Devices and methods for simultaneous determination of intrinsic viscosity and non-newtonian behavior of polymers

Abstract

To provide devices and methods for rapidly and incrementally or continuously measuring rheological properties of polymers under different shear rates.SOLUTION: A device provided herein comprises at least one pump configured to accept a continuous stream of sample solution during an interval of time, an injector configured to inject a flow of the sample solution through two or more viscometers, and a computing and processing device configured to monitor and measure rheological properties of the solution under at least two shear rates simultaneously in the two or more viscometers.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 62 / 304,775, entitled "Device and Methods for Simultaneous Determination of Intrinsic Viscosity and Non-Newtonian Behavior of Polymers," filed March 7, 2016, which is incorporated by reference in its entirety herein for all purposes.

[0002] Technical Field The present disclosure relates to a means for monitoring, characterizing, and controlling the rheological properties of a polymer during its production. The present disclosure further relates to an apparatus and method for simultaneously determining the intrinsic viscosity and non-Newtonian behavior of a polymer during its production. [Background technology]

[0003] Polymer intrinsic viscosity and diffusion properties involve time-independent quantities that occur in the absence of externally applied shear (diffusion) and very small, time-independent shear (intrinsic viscosity). Polymers in melts and solutions constitute complex fluids with complex time-dependent responses to stress and flows that reflect molecular motions on a variety of lengths and time scales. The two extremes of rheology are i) purely inviscid liquids that cannot support any shear stress and flow immediately in response to such stress, and ii) solids that do not flow or deform irreversibly in response to shear stress. Most real materials lie between these extremes. Bose-Einstein condensation in helium is a rare exception, where all atoms are phase-locked to their ground state, similar to superconductivity, and have no viscosity at all while in the superfluid state.

[0004] The Deborah number (De) is a dimensionless parameter that represents the ratio of the relaxation time of a material in response to a shear stress to the experimental or observational time. For example, an inviscid body at one extreme of the rheological state (e.g. superfluid helium) has De equal to 0, whereas for a pure solid De approaches infinity.

[0005] Polymer motions, such as bond rotation between different configurations, reptation through space, and intermolecular overlap interactions, can result in a viscoelastic response in polymer solutions that can span several orders of magnitude in time or in the frequency at which stress, its conjugate variable, is applied. Fluids with viscosities that do not change with the frequency of stress are called "Newtonian" fluids. Most polymer fluids deviate from Newtonian behavior under certain conditions and are called "non-Newtonian" fluids.

[0006] Shear thinning (thixotropy) is one of the most common manifestations of non-Newtonian behavior in polymer fluids. Increasing shear can result in partial alignment of polymer or colloidal particles and flow, resulting in a decrease in viscosity. Examples include latex paint, blood, and syrup. Shear thickening is the opposite phenomenon (inverse thixotropy), where a material becomes more viscous or stiff with increasing shear, often due to shear-induced organization, such as partial crystallization. Quicksand and cornstarch in water are examples of shear-thickening materials.

[0007] In practical terms, polymer rheology, and in particular its non-Newtonian behavior, is of great importance in polymer processing. The relationship between applied stress and polymer flow determines the processability of the polymer in applications such as injection, spinning, and film blowing. Therefore, an apparatus and method for measuring the rheological properties of a polymer under different shear rates is desirable. Furthermore, an apparatus and method for monitoring, characterizing, and controlling the rheological properties of a polymer during its production is desirable. Furthermore, an apparatus and method for simultaneously determining the intrinsic viscosity and non-Newtonian behavior of a polymer during its production is desirable.

[0008] Embodiments of the present application will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 illustrates an apparatus for rapidly and stepwise or continuously measuring rheological properties of polymer samples according to an example embodiment of the present disclosure; [Diagram 2] In accordance with an example embodiment of the present disclosure, an alternative apparatus for rapidly and stepwise or continuously measuring the rheological properties of a polymer sample is presented, in which the polymer sample can be injected at desired time intervals; [Diagram 3] In accordance with an example embodiment of the present disclosure, an alternative apparatus for rapidly and incrementally or continuously measuring the rheological properties of a polymer sample is presented, in which the polymer sample can be injected at desired time intervals while flowing continuously through the viscometer; [Figure 4] 1 shows data for a 10 mM NaCl aqueous solution containing 3 mg / ml xanthan using an apparatus and method including multiple viscometers with capillary tubes having internal diameters of 0.01 inch, 0.02 inch, 0.03 inch, and 0.04 inch according to an example embodiment of the present disclosure; [Diagram 5] According to an example embodiment of the present disclosure, data is shown for the same conditions used in FIG. 4, but using only a flow rate of Q=3 ml / min for each viscometer; [Figure 6] An alternative apparatus for rapidly and incrementally or continuously measuring the rheological properties of a polymer sample is disclosed, which comprises providing a polymer solution sample stream from an ACOMP unit to a viscometer and an optional concentration detector; and [Figure 7] 1 illustrates an ACOMP unit in accordance with an example embodiment of the present disclosure.

[0010] It should be understood that there are many possible variations and that the invention is not limited to the arrangements and instrumentality shown in the drawings. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] It will be appreciated that for brevity and clarity of description, reference numerals may be repeated among different figures where appropriate to indicate corresponding or similar elements. Additionally, a number of specific details have been described for the purpose of providing a thorough understanding of the embodiments described herein. However, it will be appreciated by those skilled in the art that the embodiments described herein may be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the relevant features being described. Likewise, the description should not be considered as limiting the scope of the embodiments described herein. The drawings are not necessarily to scale, and certain parts have been exaggerated in proportion to better show the details and features of the present disclosure.

[0012] Several definitions that apply throughout this disclosure are now presented. The term "coupled" is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to a physical connection. The term "communicatively coupled" is defined as connected, whether directly or indirectly through intervening components, and is a connection that provides for the transfer of data between the components so described. A connection may be one in which the objects are permanently connected or detachably connected. The terms "comprising," "including," and "having" are used interchangeably in this disclosure. The terms "comprising," "including," and "having" are meant to include, but are not limited to, the things so described.

[0013] The term "continuous" refers to "continuous measurements" or measurements that do not require cycles of manipulation between successive measurements, and that do not require a time gap between successive measurements, in reference to which a sample can be measured "continuously." The term "continuous," as used herein, does not require constant recording of measurements, but rather allows measurements to be made as frequently or infrequently as desired, so long as no intervening manipulation is required or performed. For example, during the implementation of the methods and techniques disclosed herein, a "continuous system" may make thousands of measurements per second, only a few measurements per second, or allow intervals of several seconds or minutes between measurements.

[0014] The present disclosure relates to a method for producing a cellulose membrane using a cellulose membrane with different shear rates ( The present invention provides an apparatus and method for rapidly and stepwise or continuously measuring the rheological properties of polymer samples under conditions of polymerization. Typically, rheological properties are measured on samples of the polymer, of the end product of a production, or of aliquots from a reaction. Such measurements are often performed in a laboratory. Although this can provide important detailed profiles of the polymer rheology, such measurements are often laborious and time consuming. If the purpose of the rheological measurements is to monitor and control the rheological properties during polymer production, approaches that merely measure multiple aliquots of the end product of a polymerization, or of individual aliquots of a polymerization process, are too slow, inaccurate, cumbersome, and ineffective.

[0015] The disclosed apparatus and methods provide a means to rapidly characterize the rheological behavior of a polymer during its production. In at least some cases, the disclosed apparatus and methods can be used in an "on-line" production environment. The apparatus and methods can be used independent of polymer production, for example, in a laboratory or in connection with any polymer sample that may be produced.

[0016] An important tool for evaluating the rheological behavior of polymer melts and concentrated solutions is the use of dynamic mechanical analysis. It consists in studying the mechanical response, i.e. the deformation, of a polymeric material to a time-dependent stress, or conversely, in measuring the stress caused by a time-dependent deformation. For simplicity, a sinusoidal driving function is usually used. For a controlled shear stress γ(t), JPEG2024174902000003.jpg20159

[0017] The in-phase part, G'(ω,T), is often called the dynamic storage modulus, which measures the pure elastic response of the material and is usually very sensitive to both frequency (ω) and temperature (T). The out-of-phase part, G'', is called the dynamic loss modulus, which measures the energy dissipation response of the material. The phase shift between the input frequency and the response is usually denoted δ, which is the ratio of the moduli: JPEG2024174902000004.jpg11103

[0018] A purely viscous material with no elasticity can be thought of as having δ = π / 2, while a lossless elastic material can be thought of as having δ = 0. A typical polymer will exhibit a complex interplay between how G' and G'' behave with respect to ω. It is common for G' and G'' to cross one or more times as ω increases.

[0019] Polymer rheology is a very complex field, and there are many other methods available to characterize the viscoelastic and mechanical behavior of various types of polymers in concentrated solutions, melts, and rubbery states. For example, Mooney viscosity is a measure of the torque generated by a spindle rotating at a constant angular velocity, immersed in a polymeric material between heated dies. It is one of the most widely used industrial measurements of the bulk viscoelastic properties of polymeric materials, especially elastomers and rubbers. Often, Mooney viscosity is of greater practical significance than the dynamic mechanical specifications of G' and G''. The concept of Mooney viscosity is well founded in the principles of continuum mechanics, but involves experimentally determined Mooney viscosity and related parameters.

[0020] Another example of a test that evaluates the viscoelastic and mechanical behavior of a polymer is the melt flow index. The melt flow index essentially consists of measuring the amount of polymer melt that flows through a tube of certain dimensions under a certain pressure for a specified length of time. Experimentally, the apparatus is typically a small extruder. The index calculated from the data obtained has a certain inverse relationship with the viscosity at any temperature and is indirectly related to the polymer molecular weight.

[0021] In accordance with at least one aspect of the present disclosure, the apparatus and methods disclosed herein can use two or more capillary viscometers in series to form a capillary train. Each capillary can impart a different average shear rate to the liquid flowing therethrough, resulting in a partial map of solution viscosity versus average shear rate, (η), versus . The capillaries measure the reduced viscosity η of the polymer. r The capillary train may include a low shear capillary for determining the viscosity, from which the intrinsic viscosity [η] may be determined or estimated. The capillary train may optionally include one or more back pressure regulators or other devices to at least facilitate accurate measurements and avoid imperfections in the data.

[0022] The pressure drop across a capillary tube of length L and radius R, when a fluid exhibiting viscosity η flows through the capillary tube with a flow rate Q, is given by the Poiseuille equation: JPEG2024174902000005.jpg10103

[0023] The average shear rate in parabolic capillary flow is: JPEG2024174902000006.jpg10103

[0024] Viscosity η o A polymer with intrinsic viscosity [η] is added to a pure fluid of p The total fluid viscosity when added at JPEG2024174902000007.jpg8117

[0025] It is measured directly by measuring the pressure drop ΔP with a differential pressure transducer at a given Q across a capillary tube of known L and R. [η] is the polymer intrinsic viscosity (IV), which is the limit that the reduced viscosity approaches as the polymer concentration approaches zero. The reduced viscosity η r (i.e., RV) is calculated from the measured η by: JPEG2024174902000008.jpg11103

[0026] where V is the voltage or other signal from the pressure transducer (e.g., the pressure itself) and c is the known or measured polymer concentration. Note that L, R, ΔP, and Q are not present in Equation 6, which means that a viscometer utilizing a pressure transducer does not require calibration for the absolute value of ΔP, as long as the response of the viscometer is linear. From Equation 5, it can be seen that the drop in viscosity is related to IV by: JPEG2024174902000009.jpg6103

[0027] η in CGS system r and [η] is in cm 3 / g, C p is g / cm3 where η is in poise.

[0028] In at least some cases, the devices and methods disclosed herein use multiple viscometers in a fluid flow path to measure η r versus This provides the ability to identify the RV vs. JPEG2024174902000011.jpg716 is made dimensionless by simply dividing it by IV, i.e., RV / IV ratio If you change it to JPEG2024174902000012.jpg716, the density will be canceled out.

[0029] As shown in Equation 6, the polymer concentration C p is η r It is necessary to obtain C p For example, in laboratory experiments, p Prepare a known solution or in a reactor p It may be known, for example, when monitoring a p If is unknown, C p In accordance with at least one embodiment of the present disclosure, C p can be measured using a concentration detector that may be included in the devices and methods disclosed herein. Types of concentration detectors and means for including them in the devices and methods disclosed herein are described below.

[0030] Considering the ratio RV / IV, it is possible that the concentrations cancel out, providing some flexibility when the polymer solution concentration is not fully known. However, RV / IV is a non-dimensional quantity, even though it is itself a dimensionless quantity. pIt is expected that the non-Newtonian effects will be a strong function of C p However, small concentration intervals around a given concentration, such as within 10% of the given concentration, are not likely to affect RI / IV significantly. Further experiments will clarify the level of error in RV / IV as a function of concentration, i.e., what we should look for is to estimate JPEG2024174902000013.jpg913: JPEG2024174902000014.jpg13117

[0031] Any uncertain ΔC p Regarding the difference If JPEG2024174902000015.jpg413 is small enough, this formula can be very powerful because it allows us to get an accurate and precise value of RI / IV while still keeping C p This is because it means that there can be a considerable amount of uncertainty in the

[0032] 1 is a diagram illustrating an apparatus 100 for rapidly and stepwise or continuously measuring the rheological properties of a polymer sample, according to an example embodiment of the present disclosure. As shown in FIG. 1, the apparatus 100 can include a pump 110 coupled to a sample 105. The pump 110 is further coupled to a capillary viscometer 115, 120, 125 through a series of capillaries of different radii via a serial sample path, and measures the drop viscosity η at multiple average shear rates in the sample path. r(RV). The capillary viscometers 115, 120, 125 are depicted in FIG. 1 as capillaries connected to differential pressure transducers via a "T-connection." Although the apparatus 100 is depicted as having three viscometers, the apparatus 100 may have any number of viscometers in series. Thus, the viscometer 125 may be considered as "viscometer n," indicating that the apparatus 100 is any design having any "n" number of viscometers, including zero, in addition to 115, which is "viscometer 1," and 120, which is "viscometer 2." Any number of viscometer arrangements are within the spirit and scope of the present disclosure. Although FIG. 1 depicts the apparatus 100 as having viscometers 115, 120, 125 arranged in series, the apparatus 100 may have viscometers 115, 120, 125 arranged in parallel or in a combination of series and parallel. The arrangement of the viscometers is not limited to the series arrangement depicted in FIG. 1. In at least some cases, the two or more viscometers can be fluidly coupled. In other cases, the two or more viscometers cannot be fluidly coupled.

[0033] The pump 110 is configured to introduce a flow of the polymer sample 105 through the viscometers 115, 120, 125 for a time interval. In at least some cases, the pump 110 is configured to introduce a flow of the polymer sample 105 such that it continuously flows the sample 105 through the viscometers 115, 120, 125. Apparatuses with multiple pumps are within the spirit and scope of the present disclosure. In at least some cases, the apparatus 100 can include multiple pumps. For example, the apparatus 100 can include two pumps, three pumps, or any number of pumps. In at least some cases, the apparatus 100 can include one pump per viscometer. In such cases, each pump 110 is configured to introduce a flow of the polymer sample 105 through one viscometer. The pump 110 can be any suitable type of pump, including, but not limited to, a piston pump or an isocratic pump, such as those found in HPLC systems, a syringe pump, or a peristaltic pump. In at least some cases, the flow in the device 100 can be continuous through all of the detectors.

[0034] According to at least one embodiment of the present disclosure, sample 105, as well as sample 205 and sample 305 depicted in Figures 2 and 3, can include a polymer sample in solution, a polymer sample in a mixture or composition, or a polymer sample without a solvent, or a polymer sample under different shear rates. In at least some cases, sample 105, 205, 305 can be drawn from a reactor or vessel containing an unreacted sample. Sample 105, 205, 305 can also include a polymer solution, as well as one selected from the group consisting of a polymer, a colloid, a product produced by a chemical reaction, an aliquot from another sample, an end product of a chemical reaction, and any combination thereof.

[0035] As depicted in FIG. 1, the apparatus 100 includes a computer system 150 coupled to the viscometers 115, 120, 125. The computer system 150 provides a means for recording signals from the viscometers as well as a means for calculating the RV from the measurements. As further depicted in FIG. 1, the apparatus 100 can optionally include a concentration detector 130 for determining the polymer concentration in the solution when the concentration is unknown. If the polymer concentration is known, the concentration detector 130 can be omitted from the apparatus 100. The concentration detector 130 can include, but is not limited to, a differential refractive index detector, an ultraviolet or visible spectrophotometer, an infrared absorption detector, a Raman detector, a polarimeter, a conductivity sensor, an evaporative light scattering detector, an NMR, or any other suitable detector. After passing through the optional concentration detector 130, the polymer sample can be discarded to waste 170.

[0036] In accordance with at least one embodiment of the present disclosure, the measurements made by viscometers 115, 120, 125, as well as the measurements of concentration by concentration detector 130, can be continuous. In such cases, computer system 150 can be configured to identify the RV based on the continuous measurements made by viscometers 115, 120, 125.

[0037] FIG. 2 depicts an alternative apparatus 200 for rapidly and stepwise or continuously measuring the rheological properties of a polymer sample according to an example embodiment of the present disclosure, where the polymer sample can be injected at desired time intervals. In at least some cases, the apparatus 200 is capable of intermittent or stepwise measurement of viscosity RV and concentration. This can be accomplished through pulsed injection of the polymer sample into a continuously flowing solvent stream, instead of continuous feeding of the polymer sample from a pump through a detector. As depicted in FIG. 2, the apparatus 200 includes a pump 210 coupled to a polymer sample 205 and an autoinjector 260. The pump 210 and the autoinjector 260 may be coupled in an injection loop 265, which together allow for pulsing of the sample through the viscometers 215, 220, 225, and an optional concentration detector 230. For example, the injection loop 265 can be similar to that used in gel permeation chromatography. The injection loop 265 can include a metering device, such as a metering pump, as well as a control valve or other type of fluid metering equipment. The volume of the injection loop can range from as little as 10 microliters for very short pulses to up to several milliliters when it is desired to achieve a pulse with a plateau value. Pulsed injection of sample 205 into detectors 215, 220, 225, 230 can be done at desired intervals, evenly or unevenly spaced. A stream of polymer sample can be injected into the entire detector train at desired intervals. Sample injection can also be automated using a programmable injection valve, which can be programmed to inject at any desired interval.

[0038] As depicted in FIG. 2, pump 210, autoinjector 260, and injection loop 265 are coupled to capillary viscometers 215, 220, 225 in a manner similar to that described above with respect to FIG. 1. Although apparatus 200 is depicted as having three viscometers, apparatus 200 may have any number of viscometers in series. Viscometer 225 may therefore be considered a "viscometer n," indicating that apparatus 200 may be any design having any "n" number of viscometers, including zero, in addition to 215, "viscometer 1," and 220, "viscometer 2." Any arrangement of any number of viscometers is within the spirit and scope of the present disclosure. Although FIG. 2 depicts apparatus 200 as having viscometers 215, 220, 225 arranged in series, apparatus 200 may have viscometers 215, 220, 225 arranged in parallel or in a combination of series and parallel. The arrangement of the viscometers is not limited to the series arrangement depicted in FIG.

[0039] In at least some cases, the apparatus 200 can include multiple pumps. For example, the apparatus 200 can include two pumps, three pumps, or any number of pumps. In at least some cases, the apparatus 200 can include one pump per viscometer.

[0040] As depicted in FIG. 2, the apparatus 200 includes a computer system 250 coupled to the viscometers 215, 220, 225. The computer system 250 provides a means for recording signals from the viscometers as well as a means for calculating the RV from the measurements. As further depicted in FIG. 2, the apparatus 200 can optionally include a concentration detector 230 for determining the polymer concentration in the solution when the concentration is unknown. If the polymer concentration is known, the concentration detector 230 can be omitted from the apparatus 200. The concentration detector 230 can include, but is not limited to, a differential refractive index detector, an ultraviolet or visible spectrophotometer, an infrared absorption detector, a Raman detector, a polarimeter, a conductivity sensor, an evaporative light scattering detector, an NMR, or any other suitable detector. After passing through the optional concentration detector 230, the polymer sample can be discarded to waste 270.

[0041] 3 depicts an alternative apparatus 300 for rapid and stepwise or continuous measurement of rheological properties of a polymer sample, according to an example embodiment of the present disclosure, in which the polymer sample can be injected at desired time intervals while flowing continuously through a viscometer. In at least some cases, the apparatus 300 can perform intermittent or stepwise measurements of concentration via an injection valve, secondary pump, or other device configured to provide periodic pulses of sample 305 to a concentration detector 330 while allowing the sample to flow continuously through the viscometers 315, 320, 325. This can be accomplished with an automatic injector 360 coupled to a pump 310 via the viscometers 315, 320, 325. As depicted in FIG. 3, the pump 310 is coupled to the sample 305. In such a case, a continuous flow through the viscometers 315, 320, 325 occurs. This periodic concentration value C is then calculated. p is fed back to a computer system 350 which is coupled to the viscometers 315, 320, 325 and the concentration detector 330, thereby providing a means for calculating the viscosity and RV results.

[0042] Pulsed injections of sample 305 into concentration detector 330 can be done at desired intervals, evenly or unevenly spaced. A stream of polymer sample can be injected into the entire detector train at desired intervals. Sample injection can also be automated using a programmable injection valve, which can be programmed to inject at any desired interval.

[0043] Although the apparatus 300 is depicted with three viscometers, the apparatus 300 can have any number of viscometers in series. Thus, the viscometer 325 can be considered as "viscometer n" to indicate that the apparatus 300 is any design that includes any "n" number of viscometers, including zero, in addition to 315, "viscometer 1," and 320, "viscometer 2." Any number of viscometer arrangements are within the spirit and scope of the present disclosure. Although FIG. 3 depicts the apparatus 300 as including viscometers 315, 320, 325 arranged in series, the apparatus 300 can include viscometers 315, 320, 325 arranged in parallel or in a combination of series and parallel. The arrangement of the viscometers is not limited to the series arrangement depicted in FIG. 3.

[0044] In at least some cases, the apparatus 300 can include multiple pumps. For example, the apparatus 300 can include two pumps, three pumps, or any number of pumps. In at least some cases, the apparatus 300 can include one pump per viscometer.

[0045] As depicted in FIG. 3, the apparatus 300 includes a computer system 350 coupled to the viscometers 315, 320, 325. The computer system 350 provides a means for recording signals from the viscometers as well as a means for calculating RV from the measurements. As further depicted in FIG. 3, the apparatus 300 can optionally include a concentration detector 330 for determining the polymer concentration in the solution when the concentration is unknown, which can include, but is not limited to, a differential refractive index detector, an ultraviolet or visible spectrophotometer, an infrared absorption detector, a Raman detector, a polarimeter, a conductivity sensor, an evaporative light scattering detector, an NMR, or any other suitable detector. After passing through the optional concentration detector 330, the polymer sample can be discarded to waste 370.

[0046] FIG. 4 shows data for a 10 mM NaCl solution containing 3 mg / ml xanthan collected using an apparatus and method including multiple viscometers with capillaries having internal diameters of 0.01 inch, 0.02 inch, 0.03 inch, and 0.04 inch, in accordance with an example embodiment of the present disclosure. Specifically, the data shown in FIG. 4 was collected using an apparatus similar to that shown in FIG. 1, but without a concentration detector and including two viscometers. The concentration of the xanthan sample solution was known, so no concentration detector was required. The data shown in FIG. 4 was collected using flow rates ranging from 0.5 ml / min to 8 ml / min. For larger diameter capillaries, a Validyne P55-28 pressure transducer, for example, can be used in conjunction, and for smaller diameter capillaries, a Validyne P55-46 transducer, for example, can be used in series. A solution was formed by adding xanthan, a biopolymer, at 3 mg / ml to a 10 mM NaCl solution. The very strong shear thinning effect is clearly visible in Figure 4. The data points were obtained by varying the flow rate of the solution from 0.5 ml / min to 8 ml / min through a capillary with different shear rates to obtain a wider range of shear rates than would be produced by a single flow rate. However, the use of multiple flow rates is not necessary for use of the device, since at any flow rate, η rThis is because the difference is extremely large, indicating the shear thinning effect.

[0047] Figure 5 shows data for the same conditions used in Figure 4, but using only a flow rate of Q=3 ml / min for each viscometer, in accordance with an example embodiment of the present disclosure. The data shown in Figure 5 was obtained for the four capillaries shown, two taken at a time to calculate the average shear rate via Equation 4. This type of data can be useful for on-line monitoring of polymerization reactions, as it can be conveniently obtained without varying the flow rate.

[0048] According to at least one embodiment of the present disclosure, a series of atmospheric pressure transducers can be used that measure the pressure difference across each of the tubes with different diameters between them. In some cases, the apparatus herein can include: (i) the use of "T" connectors between viscometers to change polymer concentration and solvent conditions such as solvent composition, mixed solvents, or changes in ionic strength, pH, etc.; (ii) temperature changes between viscometers; (iii) the use of parallel paths in addition to or instead of serial paths; (iv) the use of flow ramps, either stepped or continuous ramps, to allow additional shear rate data to be obtained; (v) the specification that measurements are made with a continuous flow of polymer sample over a time interval, where "time interval" can include less than a minute to make only a few measurements and stop, or last for minutes or hours or the entire reaction period or polymer production cycle (e.g., months); and (vi) the specification that simultaneous rheological measurements can be used to control polymer production in continuous, batch, and semi-batch processes.

[0049] In accordance with at least one embodiment of the present disclosure, the apparatus and methods disclosed herein can be used in conjunction with automatic continuous on-line monitoring of a polymerization reaction (ACOMP), as shown in FIG. 6. As shown in FIG. 6, the viscometers 615, 620, 625, and optional concentration detector 630 of the apparatus 600 are fed a polymer solution sample stream from an ACOMP unit 690. In such a case, the "front end" of the ACOMP continuously extracts samples from the reactor, diluting and conditioning the samples to produce an analytical grade sample stream, on which highly accurate and precise measurements can be made. In some cases, the apparatus 600 can be coupled to the output of an ACOMP front end, which can provide samples to the apparatus for continuous, intermittent, or stepwise analysis. These measurements can also be used to actively control the polymerization reaction, either manually or automatically.

[0050] The ACOMP unit 690 may also include an optional reaction control module 695 coupled to the ACOMP unit 690 and the computer system 650. The reaction control module 695 may be configured to perform online monitoring of the rheological properties of the polymer sample by obtaining the rheological properties, such as RV, from the computer system 650. Based on the rheological properties obtained from the computer system 650 and / or the online monitoring of the rheological properties, the reaction control module 695 may also control the derivatization or chemical or enzymatic modification process steps to obtain a polymer or a solution or mixture of polymers with desired rheological properties. In such a control, the derivatization or modification process steps may be controlled by the reaction control module 695, including the type and amount of reagents used, temperature, pressure, and process time, which communicates one or more commands to the ACOMP unit 690, thereby causing the ACOMP unit 690 to adjust the control agent that may cause the derivatization or modification of one or more process steps. Control agents that may be controlled to obtain a polymer with desired rheological properties can include, but are not limited to, acids, bases, carboxylating agents, sulfonating agents, methylating agents, or any other suitable agents.

[0051] The reaction control module 695 can also control the production of EPDM, SBR, or other rubbers using steady state reactions, where the equipment is used to identify when the reaction has reached a desired steady state that produces a polymer with the required rheological properties. The reaction control module 695 can also be used to control and maintain the steady state once it has been reached by continuously monitoring the rheological properties of the polymer produced during the steady state. Similarly, the measurements of the reaction control module can also be used to control this type of polymerization when carried out in a batch or semi-batch process. As used herein, "batch process" refers to the use of a reactor to carry out the polymerization process without significant addition of materials to the reactor during the process. The term "semi-batch" as used herein refers to a polymerization reaction in which reagents such as monomers, initiators, catalysts, branching agents, and chain transfer agents are introduced into the reactor during the reaction.

[0052] 6, the apparatus 600 includes an ACOMP unit 690 coupled to a pump 610, which is further coupled to viscometers 615, 620, 625. The pump 610 can deliver a polymer sample from the ACOMP unit 690 to the viscometers 615, 620, 625 via a serial sample path through a series of capillaries of different radii, and can measure the drop in viscosity η at multiple average shear rates in the sample path. r (RV). Although the apparatus 600 is depicted with three viscometers, the apparatus 600 can have any number of viscometers in series. Thus, the viscometer 625 can be considered as "viscometer n" to indicate that the apparatus 600 is any design with any "n" number of viscometers, including zero, in addition to 615, "viscometer 1," and 620, "viscometer 2." Any number of viscometer arrangements are within the spirit and scope of the present disclosure. Although FIG. 6 depicts the apparatus 600 as having viscometers 615, 620, 625 arranged in series, the apparatus 600 can have viscometers 615, 620, 625 arranged in parallel or in a combination of series and parallel. The arrangement of the viscometers is not limited to the series arrangement depicted in FIG. 6.

[0053] In at least some cases, the apparatus 600 can include multiple pumps. For example, the apparatus 600 can include two pumps, three pumps, or any number of pumps. In at least some cases, the apparatus 600 can include one pump per viscometer.

[0054] As depicted in Figure 6, the apparatus 600 includes a computer system 650 coupled to the viscometers 615, 620, 625. The computer system 650 provides a means for recording signals from the viscometers as well as a means for calculating the RV from the measurements. As further depicted in Figure 6, the apparatus 600 can include a concentration detector 630, which can include, but is not limited to, a differential refractive index detector, an ultraviolet or visible spectrophotometer, an infrared absorption detector, a Raman detector, a polarimeter, a conductivity sensor, an evaporative light scattering detector, or any other suitable detector. After passing through the concentration detector 630, the polymer sample can be disposed of in a waste section 670.

[0055] The ACOMP unit 690 depicted in Figure 6 and further described below with respect to Figure 7 can also be coupled to pumps 110, 210, 310, respectively, to deliver polymer samples to the apparatuses 100, 200, 300, respectively, of Figures 1, 2, and 3. Thus, the ACOMP unit 690 can be in fluid contact with the fully discrete mode apparatus 200 shown in Figure 2 or the discrete concentration / continuous viscometer mode apparatus 300 shown in Figure 3.

[0056] 7 illustrates an ACOMP unit 700, such as the ACOMP unit 690 depicted in FIG. 6, in accordance with an example embodiment of the present disclosure. The ACOMP unit 700 includes an ACOMP reactor control interface 701 and an ACOMP analysis control interface 702. In at least some cases, the ACOMP reactor control interface 701 and the ACOMP analysis control interface 702 are controlled by a programmable logic controller (PLC) control system (not shown), which is coupled to a computing device (not shown). The computing device can be a desktop or laptop computer, a smartphone, a tablet, or any other similar device. The computing device allows for visualization and control of process control variables and factors of the ACOMP unit 700.

[0057] The ACOMP reactor control interface 701 can control various elements of the ACOMP unit 700. One element is the reactor 710. The reactor 710 can be any reactor capable of controlling the control agent described above with respect to FIG. 6. The ACOMP unit 700 can further include a mixer 740, which can be located outside the reactor 710 and can mix the sample entering the reactor 710. The ACOMP unit 700 can further include flow controllers 720, 722, which can deliver gas to the reactor 710. As depicted in FIG. 7, the ACOMP unit 700 can further include pumps 730, 732, 734, which can deliver solutions or liquids to the reactor 710. The reactor 710 and the contents contained therein can also be heated or cooled by a temperature controller 736. Reactor 710 may also be connected to a recycle pump 750, which is connected to the bottom of reactor 710 via an outlet (not shown) and a ball valve (not shown). The contents of reactor 710 are continuously extracted through recycle pump 750 and recycled back to the top of reactor 710. Extraction pump 760 connects ACOMP system interface 702 to reactor control interface 701 via recycle pump 750.

[0058] As depicted in FIG. 7, the extracted reactor contents can be combined with a stream of quench solvent from a solvent source 768. Once the reactor contents are combined with the quench solvent, the combined stream can be sent to a dynamic mixing chamber 770 via inert propylene tubing. The mixing chamber 770 can be used to actively mix and mix the two continuous streams of reactor contents and solvent into one homogenous mixture. After the homogenous solution leaves the mixing chamber, it can be passed through a filtration system 772 to remove any particles or gels that may have been removed from the reaction 710 involving the reactor contents. The filtered homogenous solution can then be run through one or more in-line analytical detectors, such as a UV / Visible spectrophotometer 774. A portion of the sample stream can be diverted by a pump 790 to one or more viscometers 792, such as those described above with respect to FIGS. 1-3, and a multi-angle laser light scattering (MALLS) detector 794. The ACOMP unit 700 includes an on-board analytical package 776 that can analyze data obtained by the detectors 774, 792, 794. The analytical package 776 can, in some cases, respond to manually operated triggers in conjunction with the automation and control software. These triggers instruct the analytical software to perform key analytical algorithms appropriate for each step or stage of the polymer reaction process. Process characteristics 778 can be identified based on the analysis performed by the analytical package 776.

[0059] The ACOMP unit 700 may further include a process controller 780 coupled to the ACOMP reactor control interface 701 and the ACOMP analytical control interface 702 to provide a means for a user to communicate with the ACOMP reactor control interface 701 to perform operations that can control or affect the polymer reaction in the reactor 710.

[0060] Potential applications of the apparatus and methods disclosed herein include the measurement of any synthetic or natural polymeric material that utilizes rheological, viscosity, or viscoelastic measurements to characterize the final product and affect the quality and performance of the polymeric material. Conventional rheological measurements include, but are not limited to, melt flow index, Mooney viscosity, and bulk viscosity, but the apparatus and methods disclosed herein allow for rapid and continuous, intermittent, or stepwise measurement of rheological properties. These properties are directly related to molecular weight, molecular weight distribution and polydispersity, branching and crosslinking, polymer architecture, processability, supramolecular architecture, self-assembly properties, viscosity control, and other similar properties. Typical products for which this type of measurement is important include, but are not limited to, biopolymers, such as xanthan, guar, alginates, pectins, gum arabic, carrageenan, chemically modified variants thereof, and derivatives thereof. Some of these applications include, but are not limited to, modification of fluid viscosity in energy, personal care, nutrition, mining, metallurgy, paper, and water treatment applications. Many synthetic polymers are also used in these fields, including, but not limited to, polyacrylamide and its copolymers and derivatives, such as p(n-isopropylacrylamide), polyvinylpyrrolidone and its copolymers, polyethylene glycol and its copolymers, and other similar synthetic polymers.

[0061] Such measurements may be important for many types of synthetic rubbers, such as styrene butadiene rubber (SBR), ethylene propylene diene monomer rubber (EPDM), ethylene propylene rubber (EP), acrylonitrile butadiene styrene (ABS), polyacrylate rubber, ethylene acrylate rubber, polybutadiene, isobutylene isoprene butyl, polyurethane, silicone rubber, or any other suitable synthetic rubber. Such measurements may also be important for many types of synthetic plastic materials, such as polyolefins, specialty styrene or acrylic plastics, etc. Using data obtained using the apparatus and methods herein, it is possible to measure RV and adjust manufacturing processes based on real-time rheologically similar measurements.

[0062] The statements in this disclosure include: Statement 1: An apparatus, comprising: at least one pump configured to receive a sample solution for a time interval; two or more viscometers; an injector configured to introduce a flow of the sample solution through the two or more viscometers; and a computer system configured to monitor and measure rheological properties of the sample solution under at least two shear rates in the two or more viscometers; The rheological properties include the viscosity of the solution. The apparatus.

[0063] Statement 2: The apparatus of statement 2, wherein the two or more viscometers are connected to one another.

[0064] Statement 3: The apparatus of statement 2 or statement 3, wherein the injector is configured to introduce the flow of the sample solution through the two or more viscometers as discrete volumetric pulses.

[0065] Statement 4: The apparatus of any one of statements 1 to 3, wherein the two or more viscometers are single capillary viscometers.

[0066] Statement 5: The apparatus according to any one of statements 1 to 4, wherein the two or more viscometers are connected in series.

[0067] Statement 6: The apparatus of any one of statements 1 to 4, wherein the two or more viscometers are connected in parallel.

[0068] Statement 7: The apparatus according to any one of statements 1 to 4, wherein the two or more viscometers are connected in a combination of serial and parallel flow paths.

[0069] Statement 8: The apparatus of any one of statements 1 to 7, wherein the change in the experimental parameters of the polymer solution is made between at least two of the two or more viscometers.

[0070] Statement 9: The apparatus of statement 8, wherein the modification is made by a "T" connection between the at least two of the two or more viscometers, the "T" connection configured to input liquid between the at least two of the two or more viscometers.

[0071] Statement 10: The apparatus of statement 8, wherein the change is an increase or decrease in the polymer concentration between the at least two of the two or more viscometers.

[0072] Statement 11: The apparatus of statement 8, wherein the change is an increase or decrease in ionic strength and / or pH between the at least two of the two or more viscometers.

[0073] Statement 12: The apparatus of statement 8, wherein the modification is the introduction of a mixed solvent between the at least two of the two or more viscometers.

[0074] Statement 13: The apparatus of statement 8, wherein the change is an increase or decrease in temperature between the at least two of the two or more viscometers.

[0075] Statement 14: The apparatus of statement 8, wherein the change is an increase or decrease in shear rate between the at least two of the two or more viscometers, and the shear rate is changed by increasing or decreasing the flow rate through the at least two or more viscometers.

[0076] Statement 15: The apparatus of statement 14, wherein the flow rate is increased or decreased intermittently or in steps.

[0077] Statement 16: The apparatus of statement 14, wherein the flow rate is increased or decreased continuously.

[0078] Statement 17: The apparatus of any one of statements 1 to 16, wherein the time interval is on the order of seconds.

[0079] Statement 18: The apparatus of any one of statements 1 to 16, wherein the time interval is on the scale of minutes.

[0080] Statement 19: The apparatus of any one of statements 1-16, wherein the time interval is on the order of one hour or longer.

[0081] Statement 20: The apparatus of any one of statements 1 to 18, wherein the time interval is from the start of the polymerization reaction process to the end of the polymerization reaction process.

[0082] Statement 21: The apparatus of any one of statements 1 to 20, wherein discrete amounts of the continuous flow of polymer solution are injected into the apparatus at timed intervals.

[0083] Statement 22: The apparatus according to any one of statements 1 to 21, further comprising a detector for measuring a polymer concentration of the sample solution.

[0084] Statement 23: The apparatus of any one of statements 1-22, further configured to inject discrete amounts of the continuous flow of polymer solution into the concentration detector at timed intervals, and configured to continuously flow a sample solution through the two or more viscometers.

[0085] Statement 24: An apparatus as described in any one of statements 1 to 23, wherein the polymer in the continuous flow sample solution received by the apparatus is produced during a polymerization reaction, and the polymerization reaction is monitored by the apparatus as described in claim 1.

[0086] Statement 25: The apparatus of any one of statements 1 to 24, wherein the polymer in the stream is provided to the apparatus by an ACOMP system.

[0087] Statement 26: The apparatus according to any one of statements 1 to 25, wherein the measurement results obtained by the apparatus are used to control the polymerization reaction.

[0088] Statement 27: The device of any one of statements 1 to 26, wherein the sample solution comprises one selected from the group consisting of a polymer, a colloid, a product produced by a chemical reaction, an aliquot from another sample, an end product of a chemical reaction, and any combination thereof.

[0089] Statement 28: A method comprising: generating a flow of a sample solution for a time interval; directing the flow of the sample solution through two or more viscometers; monitoring and measuring the viscosity of the sample solution under at least two different shear rates; and characterizing the sample based on at least two viscosity measurements obtained under the at least two different shear rates.

[0090] Statement 29: The method of statement 28, wherein the sample solution comprises a polymer.

[0091] Statement 30: The method of statement 29, further comprising determining a concentration of the polymer.

[0092] Statement 31: The method of statement 29 or statement 30, further comprising evaluating the quality of the polymer produced by the polymerization process based on the results of the characteristic analysis of the polymer.

[0093] Statement 32: The method of any one of statements 29-31, further comprising making control decisions during the polymerization process based on the characterization results of the polymer.

[0094] Statement 33: The method of any one of statements 29-32, further comprising establishing a grade switch during a continuous polymer production process based on the results of the property analysis of the polymer.

[0095] Statement 34: The method of any one of statements 29-33, further comprising maintaining a steady state of operation during the continuous polymer production process based on the results of said characterization of the polymer.

[0096] Statement 35: The method of any one of statements 29-34, further comprising reaction conditions for the polymer being produced in a batch or semi-batch reactor based on the characterization results of the polymer.

[0097] Statement 36: The method of any one of statements 29-35, further comprising controlling one or more reaction conditions, the one or more reaction conditions including a flow of monomer into the reactor, a flow of initiator or catalyst into the reactor, a flow of a branching or crosslinking agent into the reactor, a flow of a chain transfer agent into the reactor, a flow of a reaction inhibitor into the reactor, a temperature of the reactor, and an agitation speed of the reactor.

[0098] Statement 37: The method of any one of statements 29 to 36, wherein the two or more viscometers are single capillary viscometers.

[0099] Statement 38: The method of any one of statements 29 to 37, wherein the two or more viscometers are connected in series.

[0100] Statement 39: The method of any one of statements 29 to 37, wherein the two or more viscometers are connected in parallel.

[0101] Statement 40: The method of any one of statements 29 to 37, wherein the two or more viscometers are connected in a combination of serial and parallel flow paths.

[0102] Statement 41: The method of any one of statements 29-40, further comprising varying an experimental parameter of the polymer solution between at least two of the two or more viscometers.

[0103] Statement 42: The method of any one of statements 29-41, wherein the modification is made by a "T" connection between the at least two of the two or more viscometers, the "T" connection configured to input liquid between the at least two of the two or more viscometers.

[0104] Statement 43: The method of statement 41, wherein varying the experimental parameters comprises increasing or decreasing the polymer concentration between the at least two of the two or more viscometers.

[0105] Statement 44: The method of statement 41, wherein varying the experimental parameters includes increasing or decreasing ionic strength and / or pH between the at least two of the two or more viscometers.

[0106] Statement 45: The method of statement 41, wherein altering the experimental parameters includes introducing a mixed solvent between the at least two of the two or more viscometers.

[0107] Statement 46: The method of statement 41, wherein varying the experimental parameters includes increasing or decreasing the temperature between the at least two of the two or more viscometers.

[0108] Statement 47: The method of statement 41, wherein varying the experimental parameters includes increasing or decreasing a shear rate between the at least two of the two or more viscometers, the shear rate being varied by increasing or decreasing the flow rate through the at least two or more viscometers.

[0109] Statement 48: The method of any one of statements 28 to 47, wherein the flow rate is increased or decreased intermittently or in stages.

[0110] Statement 49: The method of any one of statements 28 to 47, wherein the flow rate is increased or decreased continuously.

[0111] Statement 50: The method of any one of statements 28-49, wherein the time interval is on the order of seconds.

[0112] Statement 51: The method of any one of statements 28 to 49, wherein the time interval is on the scale of minutes.

[0113] Statement 52: The method of any one of statements 28 to 49, wherein the time interval is on the order of one hour or longer.

[0114] Statement 53. The method of any one of statements 29 to 52, wherein the time interval is from the start of the polymerization reaction process to the end of the polymerization reaction process.

[0115] Statement 54: The method of any one of statements 29-53, wherein discrete amounts of the sample are injected through the at least two or more viscometers at timed intervals.

[0116] Statement 55: The method of any one of statements 29-54, further comprising measuring the polymer concentration using a detector.

[0117] Statement 56: The method of any one of statements 29-54, further comprising injecting discrete amounts of the continuous flow of sample solution into the concentration detector at timed intervals, and continuously flowing the sample solution through the two or more viscometers.

[0118] Statement 57: The method of any one of statements 29 to 56, wherein the polymer in the polymer solution stream is produced during a polymerization reaction.

[0119] Statement 58: The method of any one of statements 29 to 57, wherein the polymer in the stream is provided by an ACOMP system.

[0120] Statement 59: The method of any one of statements 29 to 58, wherein the measured viscosity is used to control the polymerization reaction.

[0121] Statement 60: An apparatus comprising: two or more viscometers; at least one pump configured to introduce a sample solution through the two or more viscometers for a time interval; and a computer system configured to monitor and measure rheological properties of the sample under at least two shear rates in the two or more viscometers, the rheological properties including the viscosity of the sample.

[0122] Statement 61: The apparatus of statement 60, wherein the sample comprises a polymer solution.

[0123] Statement 62: The apparatus of statement 60 or statement 61, wherein the at least one pump is configured to continuously introduce a sample solution through the two or more viscometers for a time interval.

[0124] Statement 63: The apparatus of any one of statements 60 to 62, wherein the two or more viscometers are connected to each other.

[0125] Statement 64: The apparatus of any one of statements 60 to 63, wherein the two or more viscometers are single capillary viscometers.

[0126] Statement 65: The apparatus of any one of statements 60 to 64, wherein the two or more viscometers are connected in series.

[0127] Statement 66: The apparatus of any one of statements 60 to 64, wherein the two or more viscometers are connected in parallel.

[0128] Statement 67: The apparatus of any one of statements 60 to 64, wherein the two or more viscometers are connected in a combination of serial and parallel flow paths.

[0129] Statement 68: The apparatus of any one of statements 61 to 67, wherein the change in the experimental parameters of the polymer solution is made between at least two of the two or more viscometers.

[0130] Statement 69: The apparatus of statement 68, wherein the modification is made by a "T" connection between the at least two of the two or more viscometers, the "T" connection configured to input liquid between the at least two of the two or more viscometers.

[0131] Statement 70: The apparatus of statement 68, wherein the change is an increase or decrease in the polymer concentration between the at least two of the two or more viscometers.

[0132] Statement 71: The apparatus of statement 68, wherein the change is an increase or decrease in ionic strength and / or pH between the at least two of the two or more viscometers.

[0133] Statement 72: The apparatus of statement 68, wherein the modification is the introduction of a mixed solvent between the at least two of the two or more viscometers.

[0134] Statement 73: The apparatus of statement 68, wherein the change is an increase or decrease in temperature between the at least two of the two or more viscometers.

[0135] Statement 74: The apparatus of statement 68, wherein the change is an increase or decrease in shear rate between the at least two of the two or more viscometers, and the shear rate is changed by increasing or decreasing the flow rate through the at least two or more viscometers.

[0136] Statement 75: The apparatus of statement 74, wherein the flow rate is increased or decreased intermittently or in steps.

[0137] Statement 76: The apparatus of statement 74, wherein the flow rate is increased or decreased continuously.

[0138] Statement 77: The apparatus of any one of statements 60-76, wherein the time interval is on the order of seconds.

[0139] Statement 78: The apparatus of any one of statements 60 to 76, wherein the time interval is on the scale of minutes.

[0140] Statement 79: The apparatus of any one of statements 60-76, wherein the time interval is on the order of one hour or longer.

[0141] Statement 80: The apparatus of any one of statements 61-78, wherein the time interval is from the start of the polymerization reaction process to the end of the polymerization reaction process.

[0142] Statement 81: The apparatus of any one of statements 61-80, wherein discrete amounts of the continuous flow of polymer solution are injected into the apparatus at timed intervals.

[0143] Statement 82: The apparatus of any one of statements 61 to 81, further comprising a detector for measuring a polymer concentration of the sample solution.

[0144] Statement 83: The apparatus of statement 82, further configured to inject discrete amounts of the continuous flow of polymer solution into the concentration detector at timed intervals, and configured to continuously flow a sample solution through the two or more viscometers.

[0145] Statement 84: An apparatus as described in any one of statements 61 to 83, wherein the polymer in the continuous flow sample solution received by the apparatus is produced during a polymerization reaction, and the polymerization reaction is monitored by the apparatus as described in claim 1.

[0146] Statement 85: The apparatus of statement 84, further comprising an ACOMP unit configured to deliver the sample to the at least one pump.

[0147] Statement 86: The apparatus of statement 85, wherein the measurement results obtained by the apparatus are used to control the polymerization reaction.

[0148] Statement 87: An apparatus comprising: two or more viscometers; at least one pump configured to introduce a sample solution through the two or more viscometers during a time interval; and a computer system configured to monitor and measure rheological properties of the sample solution under at least two shear rates in the two or more viscometers, wherein the rheological properties include the viscosity of the sample.

[0149] Statement 88: The apparatus of statement 87, wherein the sample solution comprises a polymer.

[0150] Statement 89: The apparatus of statement 87 or 88, wherein the two or more viscometers are connected to each other.

[0151] Statement 90: The apparatus of any one of statements 87-89, further comprising an injector coupled to the at least one pump and the two or more viscometers.

[0152] Statement 91: The apparatus of statement 90, wherein the injector is configured to introduce the flow of the sample solution through the two or more viscometers as discrete volumetric pulses.

[0153] Statement 92: The apparatus of any one of statements 87-89, wherein the at least one pump is configured to continuously introduce a sample solution through the two or more viscometers for a time interval.

[0154] Statement 93: The apparatus of any one of statements 87 to 92, wherein the two or more viscometers are single capillary viscometers.

[0155] Statement 94: The apparatus of any one of statements 87 to 93, wherein the two or more viscometers are connected in series.

[0156] Statement 95: The apparatus of any one of statements 87 to 93, wherein the two or more viscometers are connected in parallel.

[0157] Statement 96: The apparatus of any one of statements 87 to 93, wherein the two or more viscometers are connected in a combination of serial and parallel flow paths.

[0158] Statement 97: The apparatus of any one of statements 87 to 96, wherein the change in the experimental parameters of the polymer solution is made between at least two of the two or more viscometers.

[0159] Statement 98: The apparatus of statement 97, wherein the modification is made by a "T" connection between at least two of the two or more viscometers, the "T" connection configured to input liquid between the at least two of the two or more viscometers.

[0160] Statement 99: The apparatus of statement 97, wherein the change is an increase or decrease in the polymer concentration between the at least two of the two or more viscometers.

[0161] Statement 100: The apparatus of statement 97, wherein the change is an increase or decrease in ionic strength and / or pH between the at least two of the two or more viscometers.

[0162] Statement 101: The apparatus of statement 97, wherein the modification is the introduction of a mixed solvent between the at least two of the two or more viscometers.

[0163] Statement 102: The apparatus of statement 97, wherein the change is an increase or decrease in temperature between the at least two of the two or more viscometers.

[0164] Statement 103: The apparatus of statement 97, wherein the change is an increase or decrease in shear rate between the at least two of the two or more viscometers, and the shear rate is changed by increasing or decreasing the flow rate through the at least two or more viscometers.

[0165] Statement 104: The apparatus of statement 103, wherein the flow rate is increased or decreased intermittently or in steps.

[0166] Statement 105: The apparatus of statement 103, wherein the flow rate is increased or decreased continuously.

[0167] Statement 106: The apparatus of any one of statements 87 to 105, wherein the time interval is on the order of seconds.

[0168] Statement 107: The apparatus of any one of statements 87 to 105, wherein the time interval is on the scale of minutes.

[0169] Statement 108: The apparatus of any one of statements 87 to 105, wherein the time interval is on the order of one hour or longer.

[0170] Statement 109: The apparatus of any one of statements 87 to 108, wherein the time interval is from the start of the polymerization reaction process to the end of the polymerization reaction process.

[0171] Statement 110: The apparatus of any one of statements 87-109, wherein discrete amounts of the continuous flow of polymer solution are injected into the apparatus at timed intervals.

[0172] Statement 111: The apparatus of any one of statements 87 to 110, further comprising a detector for measuring a polymer concentration of the sample solution.

[0173] Statement 112: The apparatus of statement 111, further configured to inject discrete amounts of the continuous flow of polymer solution into the concentration detector at timed intervals, and configured to continuously flow a sample solution through the two or more viscometers.

[0174] Statement 113: An apparatus as described in any one of statements 87 to 112, wherein the polymer in the continuous flow sample solution received by the apparatus is produced during a polymerization reaction, and the polymerization reaction is monitored by the apparatus as described in claim 1.

[0175] Statement 114: The apparatus of any one of statements 87-113, further comprising an ACOMP unit capable of providing a sample to the pump.

[0176] Statement 115: The apparatus of any one of statements 87 to 114, further comprising a reaction control unit configured to control the polymerization reaction based on measurement results obtained by the computer system.

[0177] Statement 116: The apparatus of statement 87, wherein the sample solution comprises one selected from the group consisting of a polymer, a colloid, a product of a chemical reaction, an aliquot from another sample, an end product of a chemical reaction, and any combination thereof.

Claims

1. 1. An apparatus comprising: Two or more viscometers; at least one pump configured to introduce a sample solution through the two or more viscometers for a time interval; and a computer system configured to monitor and measure the rheological properties of the sample solution under at least two different shear rates in the two or more viscometers; The rheological properties include the viscosity of the solution. The apparatus.

2. The device of claim 1 , wherein the sample solution comprises a polymer.

3. The apparatus of claim 1 , wherein the two or more viscometers are coupled to one another.

4. The apparatus of claim 1 , further comprising a syringe coupled to the at least one pump and the two or more viscometers.

5. 5. The apparatus of claim 4, wherein the injector is configured to introduce the flow of the sample solution through the two or more viscometers as discrete volumetric pulses.

6. 10. The apparatus of claim 1, wherein the at least one pump is configured to continuously introduce a sample solution through the two or more viscometers for an interval of time.

7. The apparatus of claim 1 , wherein the two or more viscometers are single capillary viscometers.

8. The apparatus of claim 2 , wherein the variation in the experimental parameters of the sample solution is between at least two of the two or more viscometers.

9. The apparatus of claim 8 , wherein the change is an increase or decrease in the polymer concentration between the at least two of the two or more viscometers.

10. 9. The apparatus of claim 8, wherein the alteration is an increase or decrease in shear rate between the at least two of the two or more viscometers, the shear rate being altered by increasing or decreasing the flow rate through the at least two or more viscometers.

11. The apparatus of claim 10 , wherein the flow rate is increased or decreased in an intermittent or stepwise manner.

12. The apparatus of claim 10 , wherein the flow rate is increased or decreased continuously.

13. 6. The apparatus of claim 5, further comprising a detector for measuring a polymer concentration of the sample solution.

14. 14. The apparatus of claim 13, further configured to inject discrete amounts of the continuous flow of polymer solution into the concentration detector at timed intervals and to continuously flow a sample solution through the two or more viscometers.

15. 14. The apparatus of claim 13, further comprising an ACOMP unit configured to provide a sample to the pump.

16. 16. The apparatus of claim 15, further comprising a reaction control unit configured to control the polymerization reaction based on the measurements obtained by the computer system.

17. 1. A method comprising: generating a flow of sample solution for a time interval; conducting said sample solution stream through two or more viscometers; monitoring and measuring the viscosity of the sample solution under at least two different shear rates; and and analyzing the characteristics of the sample based on at least two viscosity measurements obtained under the at least two different shear rates. The method comprising:

18. The method of claim 17 , wherein the sample solution comprises a polymer.

19. 20. The method of claim 18, further comprising determining a concentration of the polymer.

20. 20. The method of claim 18, further comprising making reaction control decisions during the polymerization process based on the polymer characterization results.

21. 20. The method of claim 18, further comprising maintaining a steady state of operation during the continuous polymer production process based on the polymer characterization results.

22. 22. The method of claim 21, comprising controlling one or more reaction conditions, the one or more reaction conditions including: flow of monomer into the reactor, flow of initiator or catalyst into the reactor, flow of branching or crosslinking agent into the reactor, flow of chain transfer agent into the reactor, flow of reaction inhibitor into the reactor, temperature of the reactor, agitation speed of the reactor.

23. 20. The method of claim 18, further comprising varying an experimental parameter of the polymer solution between at least two of the two or more viscometers.

24. 24. The method of claim 23, wherein varying the experimental parameters comprises increasing or decreasing the polymer concentration between the at least two of the two or more viscometers.

25. 24. The method of claim 23, wherein varying the experimental parameters comprises increasing or decreasing a shear rate between the at least two of the two or more viscometers, the shear rate being varied by increasing or decreasing the flow rate through the at least two or more viscometers.

26. 20. The method of claim 18, further comprising measuring the polymer concentration using a detector.

27. 20. The method of claim 18, wherein the polymer in the continuous stream is provided by an ACOMP system.

28. 20. The method of claim 18, wherein the measured viscosity is used to control the polymerization reaction.

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