489 results about "Intrinsic viscosity" patented technology

Disclosed in the present invention are a high-strength polylactic acid material, a preparation method therefor, and use thereof, belonging to the technical field of macromolecular materials. The high-strength polylactic acid material comprises the following components in parts by weight: 80-90 parts of polylactic acid, 10-20 parts of polybutylene adipate terephthalate, 1-5 parts of a nucleating agent, and 2-5 parts of a compatibilizing agent. The mesh number of the nucleating agent is 1500-2500 mesh; the compatibilizing agent is polycaprolactone, and the intrinsic viscosity thereof is 1.0-3.0 dL / g. The present invention lowers the melting temperature and shortens the melting time of PLA and PBAT, reduces the negative impact of polymer degradation and aging on mechanical properties, produces a heterogeneous nucleation effect, and performs the function of a crystallization nucleus in the cooling crystallization stage, improving crystallization speed and crystallinity, while causing the crystalline phase structure to tend toward a spherulitic state, improving the tensile strength of the polylactic acid material.

The invention provides a superfine denier profiled polyester staple fiber and a preparation method thereof.The preparation method includes the steps of raw material pretreatment, melt spinning, nascent filament treatment, heat setting and curling, oiling and cutting off and the like, polyester chips have high intrinsic viscosity and melting point, and under the action of six-zone temperature control, a high-hole-density spinneret plate and a high draft multiple, the polyester chips are subjected to melt spinning, so that the polyester chips are prepared into the superfine denier profiled polyester staple fiber. The superfine, special-shaped and hollow polyester staple fibers are prepared. The obtained polyester staple fiber has good breaking strength, rebound resilience and a low-defect structure, the bulkiness, flexibility and structural consistency of the fiber are remarkably improved, the environment and process limitation of a traditional sea-island fiber alkali stripping method is broken through, and the polyester staple fiber is suitable for the fields of high-end filling, plush imitation, non-woven materials and the like.

The invention relates to a preparation method of a low-precipitation low-volatility polyester film, which comprises the following steps: esterifying a diol monomer and an aryl diacid monomer in the presence of a catalyst, then carrying out vacuum polycondensation, adding dipentaerythritol phosphate which accounts for 0.5-0.8 wt% of the mass of the diol monomer when the intrinsic viscosity of a system product reaches 0.52-0.57 dL / g in the polycondensation stage, and carrying out vacuum polycondensation to obtain the low-precipitation low-volatility polyester film. Performing post-treatment to obtain a core layer polyester raw material; the core layer polyester raw material and the surface layer polyester raw material are respectively added into a melt extruder for three-layer co-extrusion, and then the ABA type three-layer composite structure polyester film is obtained through two-way stretching. After the polyester film obtained by the preparation method is subjected to high temperature and / or high humidity, the haze improvement value is very low. The method is very suitable for the field with high optical performance requirements. The preparation method provided by the invention can be completed on the basis of original polyester master batch synthesis equipment, does not need to add extra large expensive equipment and process, and has the advantage of industrialization.

The present invention relates to a raw material for preparing medium-high strength polyethylene fiber by melt spinning, which is mainly composed of polyethylene with an intrinsic viscosity of 4-12 dl / g, the content of polyethylene in the raw material is not less than 99%, and its melt index is 0.1-1.0 g / 10min (190°C, weight of 5kg). The polyethylene includes two components, one is polyethylene A material with an intrinsic viscosity of 5-12 dl / g and a molecular weight distribution index of ≤4, and the other is polyethylene B material with an intrinsic viscosity of 4-7 dl / g and a molecular weight distribution index of ≥20. The raw material may also contain an antioxidant, and the mass fractions of polyethylene A material, polyethylene B material, and antioxidant in the raw material are 50-95%, 5-50%, and 0-1%, respectively. Compared with the prior art, the present invention can prepare a spinning raw material with a controllable melt index by combining polyethylene raw materials with different intrinsic viscosities and different molecular weight distribution indexes without adding diluents or various additives.

The invention relates to a PC / PET alloy material as well as a preparation method and application thereof, and belongs to the technical field of high polymer materials. The PC / PET alloy material disclosed by the invention is prepared from the following components in parts by weight: 38 to 57 parts of PC resin, 18 to 32 parts of PET resin, 9 to 16 parts of talcum powder, 1.5 to 8 parts of toughening agent and 0.05 to 0.35 part of ester exchange inhibitor, the pH value of the talcum powder is less than 9, and the D50 particle size is 2-3 [mu] m; the intrinsic viscosity of the PET resin is 0.7 to 0.9 dL / g; the ester exchange inhibitor comprises at least one of sodium pyrophosphate and disodium dihydrogen pyrophosphate. The PC resin and the medium-viscosity PET resin are compounded, and the talcum powder with small pH value and small particle size is selected, so that the degradation of PC can be reduced, the shear heat of a PC / PET system is reduced, and good impact performance and good appearance after heat retention are realized.

The invention discloses a process method for preparing a multi-component aramid copolymer through continuous polymerization, and relates to the technical field of high polymer material preparation, and the process method comprises the following steps: S1, preparing a premix: weighing one or more aromatic diamine monomers according to a certain mass ratio, dissolving the aromatic diamine monomers in an amide solvent or a solvent compounded by amides and hydrotropy salt, and stirring to obtain the premix; uniformly stirring and dissolving in a reaction kettle under the protection of a nitrogen environment to form a premix; s2, low-temperature pre-polycondensation reaction; s3, low-temperature polycondensation reaction; s4, post-treatment: neutralizing, washing and drying the multi-element aramid polymer powder obtained in S3, and removing the solvent and the hydrotropy salt to obtain pure and uniform-particle brown yellow powder; or the obtained polymerization stock solution is neutralized, defoamed and filtered to obtain a spinning stock solution, the intrinsic viscosity of the processed brown yellow powder or spinning stock solution is larger than 4.5 dL / g, the polymer powder / polymerization solution can be used for preparing the multi-element aramid fiber through spinning, and the method effectively reduces the industrial production cost of the multi-element cyclic aramid fiber and improves the production efficiency.

One embodiment of the present invention relates to an electrode binder, an electrode, a lithium ion secondary battery, or a method for producing the electrode, and the electrode binder includes an ultrahigh molecular weight olefinic polymer fine particle (A) that satisfies the following requirements (i) to (iii): (i) the intrinsic viscosity [η] measured in a decalin solvent at 135°C is in a range of 5 to 50 dl / g; (ii) the average particle diameter d50 in a mass-based particle size distribution by a Coulter counter method is in a range of 1 to 50 um; and (iii) 50% by mass or more of the particles passes through a mesh sieve with an opening of 45 µm.

The present disclosure relates to a melt-spun high-viscosity PET / low-viscosity PET two-component elastic fiber and a preparation method therefor. The preparation method adopts a six-reactor process. Terephthalic acid and ethylene glycol undergo first and second esterification reactions and first and second prepolymerization reactions, and an obtained ethylene terephthalate prepolymer is respectively introduced into a high-viscosity final polymerization reactor and a low-viscosity final polymerization reactor for polymerization reaction to obtain a high-viscosity melt and a low-viscosity melt, respectively, and then the two melts are spun together. The viscosity of the high-viscosity component can be significantly improved, and a wider range of viscosity difference between the high-viscosity and low-viscosity polyester melts can be obtained. A difference between the intrinsic viscosity of the high-viscosity melt and the intrinsic viscosity of the low-viscosity melt is 0.100-0.550; the prepared PET / PET two-component elastic fiber has high quality and high crimp shrinkage rate.

The present invention belongs to the field of polyester industrial filaments, and relates to methods for preparing a softening flame retardant and preparing a high-strength flexible flame-retardant polyester industrial yarn. The softening flame retardant is silicon dioxide which is surface grafted with polydimethylsiloxane; a preparation method therefor comprises subjecting silicon dioxide and hydroxyl-terminated polydimethylsiloxane to a grafting reaction to obtain the softening flame retardant; and the use thereof is to use the softening flame retardant and low-viscosity polyester chips as main raw materials to prepare a softening flame-retardant polyester masterbatch, which is then subjected to melt-blending and spinning together with high-viscosity polyester chips, so as to prepare a high-strength flexible flame-retardant polyester industrial yarn, wherein the intrinsic viscosity of the low-viscosity polyester chips is 0.65-0.68 dL / g, and the intrinsic viscosity of the high-viscosity polyester chips is 1.05-1.20 dL / g. The preparation methods of the present invention are simple; the flexibility and flame retardancy of the polyester industrial yarn can both be improved after the prepared softening flame retardant is added to the polyester industrial yarn as an additive; and the obtained high-strength flexible flame-retardant polyester industrial yarn has good performance.

A method for producing a polyester film, comprising mixing a recovered polyester resin (A) and a polyester resin (B) comprising an aluminum compound and a phosphorus compound, the polyester resin (A) satisfying the following (1) to (3): (1) the polyester resin (A) comprises at least one element selected from antimony, titanium, and germanium; (2) the polyester resin (A) has a total content of antimony, titanium, and germanium elements of 2 to 500 ppm by mass; and (3) the polyester resin (A) has an intrinsic viscosity of 0.5 to 0.8 dl / g.

The invention discloses a method for preparing high molecular weight thermotropic liquid crystal polyester through melt coupling solid phase polycondensation. The method comprises the following steps: mixing p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid and a catalyst 1-methylimidazole according to a specific molar ratio of (70-75): (25-30) to synthesize a liquid crystal polyester prepolymer with specific logarithmic viscosity; the preparation method comprises the following steps: crushing and drying a liquid crystal polyester prepolymer, placing prepolymer particles in a solid phase polycondensation device, accurately controlling the time and temperature of the polycondensation reaction, carrying out heating reaction in a nitrogen atmosphere to obtain high molecular weight thermotropic liquid crystal polyester, taking out the high molecular weight liquid crystal polyester, and carrying out viscosity test. In the preparation process of the prepolymer, the prepolymer with proper logarithmic viscosity can be effectively prepared by controlling the reaction temperature and time, so that the controllable preparation of the polymer is realized; the solid-phase polycondensation time required for obtaining the high-molecular-weight polymer is shortened by crushing the prepolymer into particles with different diameters, so that the solid-phase polycondensation efficiency is improved.

The invention provides a binary polyethylene composition for a lithium battery diaphragm as well as a preparation method and application of the binary polyethylene composition. The preparation method comprises the following steps: S1, carrying out first polymerization reaction on ethylene to obtain low molecular weight polyethylene with intrinsic viscosity of 2-5dl / g; the temperature of the first polymerization reaction is 60-80 DEG C, the pressure is 0.4-0.8 mPa, and the mass ratio of ethylene to hydrogen is (6000-4000): 1; s2, ethylene is subjected to a second polymerization reaction, and extra-high molecular weight polyethylene with the intrinsic viscosity of 6-12 dl / g is obtained; the temperature of the second polymerization reaction is 75-90 DEG C, the pressure is 0.5-1 mPa, and the mass ratio of ethylene to hydrogen is 4000-2000: 1; the binary polyethylene composition for the lithium battery diaphragm comprises low-molecular-weight polyethylene and extra-high-molecular-weight polyethylene. The invention effectively solves the problem of difficult processing of extra-high molecular weight polyethylene.

The invention relates to the technical field of chemical fibers, in particular to a low-melting-point polyester FDY (fully drawn yarn) preparation process which comprises the following steps: preparing raw materials, selecting polyester chips and a low-molecular-weight polyester copolymer, mixing the polyester chips and the low-molecular-weight polyester copolymer according to a ratio, melting and blending the polyester chips and the low-molecular-weight polyester copolymer with the additive amount of 5-8wt% and the intrinsic viscosity of 0.65-0.70 dL / g, and performing extrusion molding to obtain the low-melting-point polyester FDY. And putting the mixed raw materials into a screw extruder, and carrying out melt blending and spinning treatment at 250-260 DEG C. According to the low-melting-point polyester FDY and the preparation method thereof disclosed by the invention, a component regulation end is arranged, so that a synergistic effect mechanism of a polyester matrix and a low-melting-point copolymer is accurately matched in a preparation process of the low-melting-point polyester FDY, and the uniformity of melt components is ensured; meanwhile, the copolymerization structure design directivity acts on molecular chain regularity regulation and control, thermal stability fluctuation in the spinning process is inhibited in real time, it is guaranteed that the continuous forming capacity of fibers is maintained under the high-speed spinning condition, and the stability of a production line is improved.

The present invention relates to a sustained release microsphere and a sustained release preparation comprising a GLP-1 receptor agonist or a pharmaceutically acceptable salt thereof. The present invention relates to a sustained release formulation, and more specifically, to a sustained release formulation comprising a GLP-1 receptor agonist or a pharmaceutically acceptable salt thereof, the sustained-release microparticles comprise a GLP-1 receptor agonist or a pharmaceutically acceptable salt thereof, one kind of low-viscosity polylactic acid-glycolic acid copolymer (PLGA) having an intrinsic viscosity of 0.14 dL / g to 0.24 dL / g, and two or more kinds of high-viscosity polylactic acid-glycolic acid copolymers having an intrinsic viscosity of 0.32 dL / g to 0.60 dL / g, so that the sustained-release microparticles do not have the problems of excessive release and delayed release in the initial stage of a drug. Long-term sustained release can be realized, and the bioavailability is excellent.

The invention relates to a polypropylene material, in particular to a high-flow high-impact transparent polypropylene material. The polypropylene material has excellent flowability, impact property and optical property, and the simply supported beam impact strength IS [kJ.m <-2 >], flexural modulus FM [MPa], xylene soluble substance content XS [%], ethylene content ECXS [%] in xylene soluble substances, intrinsic viscosity IVXS [dl.g <-1 >] and haze H [%] meet a certain relational expression. The high-flowability and high-impact-resistance transparent polypropylene product provided by the invention has excellent flowability, impact property and optical property, and can meet the requirements of the market on the toughness of the high-flowability transparent material.

The invention relates to the technical field of battery diaphragms, in particular to a lithium ion battery diaphragm, a preparation method thereof and an electrochemical device. The lithium ion battery diaphragm comprises a base membrane and a coating formed on at least one surface of the base membrane, and the coating comprises polymer microspheres and a binder; wherein the particle size D90 of the polymer microspheres is a [mu] m, the particle size D50 is b [mu] m, the particle size D10 is c [mu] m, the intrinsic viscosity of the binder is d dL / g, and a / d is greater than or equal to 3.2 and less than or equal to 175, b / d is greater than or equal to 1.2 and less than or equal to 55, and c / d is greater than or equal to 0.4 and less than or equal to 10.

The invention relates to a preparation method of a PAN (Polyacrylonitrile) polymer liquid intrinsic viscosity and molecular weight test sample, which is characterized by comprising the following steps of: weighing 2g of PAN polymer liquid, flatly paving the PAN polymer liquid between the opposite surfaces of two flat and clean flat plates, and pressurizing the outer surfaces of the two flat plates under the pressure of not less than 5000Pa for 1 minute; separating the two flat plates, and washing the liquid films on the surfaces of the two flat plates with deionized water until the sample is completely in a white film state; boiling the soft white film in deionized boiling water for 30 minutes; the thin film is taken out and washed with deionized water for three times, and each time is not less than 30 seconds; putting into a clean aluminum foil plate, and drying for 1.5 hours in an electrothermal blowing drying box at 105 DEG C; and cooling the sample membrane in a dryer. The preparation method of the PAN polymerization liquid intrinsic viscosity and molecular weight test sample is reasonable in design, and instability of a detection result caused by organic solvents and impurities in the test sample can be avoided.

The invention discloses a composite catalyst for synthesizing polyester as well as a preparation method and application thereof, and relates to the technical field of catalysts. According to the technical scheme, the method comprises the following steps: in a nitrogen atmosphere, mixing a first metal catalyst, a slow release agent and an organic solvent, reacting at 130-150 DEG C for 1-3 hours, and distilling to separate by-products to obtain a reaction product; and adding a second metal catalyst and an activity regulator into the reaction product, reacting at 130-150 DEG C for 1-3 hours, and distilling to separate by-products, thereby obtaining the composite catalyst for synthesizing polyester. The composite catalyst for synthesizing polyester has good compatibility with water, ethylene glycol or PET oligomer, and has the characteristic of controllable catalytic activity compared with a traditional titanium catalyst. When the composite catalyst is applied to synthesis of polyester, the composite catalyst has the characteristics of few side reactions and fast ester exchange reaction, and the obtained polyester product has the advantages of high intrinsic viscosity and good product hue.

The invention relates to the technical field of high polymer material processing and process detection, and discloses an ultrasonic transmission-based regenerated polyester homogenization kettle on-line viscosity monitoring method, which comprises the following steps of: constructing a multi-channel ultrasonic transmission sensing array in a homogenization kettle to obtain melt acoustic propagation characteristics in real time; the intrinsic viscosity is dynamically analyzed based on a sound velocity-attenuation joint inversion model; viscosity data and stirring, heating and other execution units are subjected to closed-loop linkage, and technological parameters are regulated and controlled in a graded mode according to the deviation and the duration. According to the method, non-contact, real-time and accurate monitoring and active regulation and control of the viscosity of the regenerated polyester melt are realized, and the batch consistency of products and the intelligent level of production are remarkably improved.

The binder composition for a lithium ion battery electrode contains at least a poly (meth) acrylamide copolymer, which is a polymer of a monomer component including a (meth) acrylamide monomer and an unsaturated carboxylic acid group-containing monomer as monomer units, the monomer component having a molar ratio of 1: (1-100) relative to the total amount of the monomer component being 100: (1-100): (1-100): (1-100): (1-100): (1-100): (1-100). The poly (meth) acrylamide copolymer contains 30-80 mol% of a (meth) acrylamide monomer and 20-70 mol% of an unsaturated carboxylic acid group-containing monomer, and the intrinsic viscosity of the poly (meth) acrylamide copolymer is 3.5-7.5 dL / g.

The invention belongs to the technical field of PVC foaming agents, and particularly provides a PVC foaming regulator and a preparation process thereof, the preparation process of the PVC foaming regulator comprises the following steps: 1) blending a mixed monomer, an emulsifier and water to prepare a pre-emulsion; the mixed monomer comprises MMA (methyl methacrylate) and BA (butyl acrylate); 2) dissolving a cyclodextrin derivative, disaccharide and modified polyethylene glycol in a solvent, and then adding maleimide to react to prepare a precursor solution; 3, the pre-emulsion is taken for a polymerization reaction, when the monomer conversion rate ranges from 70% to 80%, the precursor solution is added into a reaction system, the reaction continues till the inner temperature drops, the reaction is stopped, then freezing demulsification and drying pulverization are conducted, and the PVC foaming regulator is obtained.The prepared PVC foaming regulator has the advantages of being moderate in intrinsic viscosity and good in foaming effect.

The preparation method comprises the following steps: sequentially carrying out esterification reaction and polycondensation reaction on terephthalic acid, ethylene glycol, equol or a derivative thereof in the presence of the catalyst to generate the modified polyester, wherein the catalyst is prepared by enabling antimony trioxide, stannous octoate, tetrabutyl titanate and triphenyl phosphite to react in a solvent at the temperature of 100 DEG C or above; the modified polyester prepared by the method has relatively high intrinsic viscosity and fracture tensile strength, can meet the application requirements of special high polymer materials, and solves the problem that the application of semi-biomass PET copolyester in the field of special high polymer materials is limited in the prior art.

The present invention addresses the problem of providing a method for producing a polyester film that uses a polyester resin that has been used and that uses at least one compound selected from the group consisting of antimony compounds, titanium compounds, and germanium compounds as a polymerization catalyst, that is not susceptible to discoloration and reduction in molecular weight even when recycled multiple times, and that has high recycling efficiency. The present invention relates to a method for producing a polyester film, the method comprising a step for mixing a recovered polyester resin (A) and a polyester resin (B) containing an aluminum compound and a phosphorus compound, the polyester resin (A) satisfying the following (1)-(3), and the polyester resin (B) satisfying the following (4). (1) The polyester resin (A) contains at least one element selected from among elemental antimony, elemental titanium, and elemental germanium. (2) The total content of elemental antimony, elemental titanium, and elemental germanium in the polyester resin (A) is 2-500 mass ppm. (3) The intrinsic viscosity of the polyester resin (A) is 0.5-0.8 dl / g. (4) The polyester resin (B) The present invention is a resin obtained by polycondensing a starting material containing di-2-hydroxyethyl terephthalate obtained by decomposing a polyester resin.

To provide a crystalline resin composition for three-dimensional modeling and a three-dimensional modeled object, which suppress thermal collapse and warping.SOLUTION: There is provided a crystalline resin composition for three-dimensional modeling, comprising a crystalline polyethylene terephthalate resin having an intrinsic viscosity of 0.81 dl / g or more.SELECTED DRAWING: None

The present disclosure provides a composition comprising a first polymer having a high intrinsic viscosity [η] of at least 500 ml / g and a second polymer having a low intrinsic viscosity [η] lower than that of the first polymer and less than 1800 ml / g. More specifically, the present disclosure provides a hydrogel and a drug formed from the composition, and a method for producing a hydrogel.

The invention relates to the technical field of polyester yarns, in particular to a high-strength polyester yarn and a preparation method thereof.The method comprises the steps that PET slices with the intrinsic viscosity of 0.85-1.00 dL / g are subjected to melt spinning and cooled through circular blowing to obtain nascent fibers, the nascent fibers are subjected to surface activating treatment through low-temperature plasma or esterase bio-enzyme, and the high-strength polyester yarn is obtained; the preparation method comprises the following steps: firstly, activating fibers, then carrying out graft copolymerization reaction on the activated fibers and graft monomer solutions such as fluorinated acrylate and acrylic acid, and finally, cleaning, drying, carrying out thermal network and winding on the composite fibers, so that the prepared polyester yarn has the breaking strength of more than or equal to 7.7 g / D, the dry heat shrinkage rate of less than or equal to 3.5% and the shrinkage tension of less than or equal to 0.03 g / D, has the high functional characteristics of lasting super-hydrophobicity, antibacterial property and the like, is excellent in washing resistance, and is suitable for industrial production. The problem that functionalization is difficult due to surface inertia of the polyester fiber is solved, and the mechanical property and the surface characteristic of the polyester fiber are comprehensively improved.

This disclosure relates to ethylene interpolymer products comprising a Melt Flow-Intrinsic Viscosity Index value, MFIVI, of from ≥0.05 to ≤0.80; a first derivative of a melt flow distribution function, formula (I) at a loading of 4000 g, of from ≥−1.85 to ≤−1.51; a sum of unsaturation, SUMU, from ≥0.047 to ≤0.100 unsaturations per 100 carbon atoms; and a residual QC catalytic metal of from ≥0.03 to ≤5 ppm of hafnium. Ethylene interpolymer products comprise at least two ethylene interpolymers. Ethylene interpolymer products are characterized by a melt index (I2) from 0.3 to 500 dg / minute, a density from 0.855 to 0.975 g / cc and from 0 to 25 mole percent of one or more a-olefins. Ethylene interpolymer products have polydispersity, Mw / Mn, from 1.7 to 25; and CDBI50 values from 1% to 98%. These ethylene interpolymer products have utility in flexible as well as rigid applications.

This invention discloses a method for preparing poly(glycolic acid-caprolactone) copolymers, belonging to the field of polymer synthesis technology. The method includes: prepolymerizing ε-caprolactone with a catalyst and initiator at 40–60°C below the melting point of glycolide under an inert atmosphere; adding glycolide and heating to 160–220°C for the main polymerization reaction; after the reaction, dissolving, precipitating, washing, and drying to obtain the poly(glycolic acid-caprolactone) copolymer. This invention utilizes the physical difference in melting points between glycolide and ε-caprolactone, preferentially prepolymerizing ε-caprolactone at a temperature below the melting point of glycolide, resulting in a higher conversion rate of ε-caprolactone than glycolide in the initial stage of the main polymerization, effectively controlling the copolymerization reaction pathway. Using this method, copolymers with a weight-average molecular weight of not less than 100,000 Da and an intrinsic viscosity of 1.8–3.5 dL / g can be obtained within a wide range of glycolide molar content from 15% to 85%, and the degradation behavior is stable and controllable. This method is simple and requires no special equipment or chain extender, making it suitable for the large-scale preparation of medical materials such as absorbable sutures and tissue repair scaffolds.

This application provides a method and device for determining the health of a silk artifact. The method includes: obtaining the initial brightness, initial intrinsic viscosity, parameter values of multiple environmental parameters, cumulative illumination time, and cumulative exposure time of the silk artifact; determining the brightness change of the silk artifact to a target prediction time using a brightness change function model based on the cumulative illumination time, cumulative exposure time, and parameter values of the multiple environmental parameters; determining the intrinsic viscosity change of the silk artifact to a target prediction time using an intrinsic viscosity change function model based on the cumulative illumination time, cumulative exposure time, and parameter values of the multiple environmental parameters; and determining the health of the silk artifact at the target prediction time based on the initial brightness, initial intrinsic viscosity, brightness change, and intrinsic viscosity change. This solution can relatively accurately predict the health of a silk artifact at a specific time, reducing the complexity of determining the health of the silk artifact.

The invention provides an anti-ultraviolet aging high-strength and high-modulus PBO (poly (p-phenylene benzobisoxazole)) fiber and a preparation method thereof. The strength of the PBO fiber is 31.6-32.3 cN / dtex. The strength retention rate is greater than or equal to 62.5%, and preferably, the strength retention rate is 62.5-90.5%. The intermittent pre-polymerization process is used for intermittently preparing a pre-polymerized material, starting from a material storage kettle, continuously conveying the material, defoaming, pre-filtering, feeding the material into a final polymerization system, adding an ultraviolet light absorber before the material enters the final polymerization system for blending modification, and then spinning, washing, oiling, drying and densifying to obtain the anti-ultraviolet aging fiber. The PBO spinning solution is high in viscosity and is easy to block equipment and pipelines, so that equipment such as a pre-polymerization kettle, a middle kettle, a defoaming kettle and a double-screw extruder should be compactly arranged in space arrangement. Meanwhile, the reaction time and the reaction temperature need to be strictly controlled, the intrinsic viscosity of materials in each process is guaranteed, the process stability is guaranteed, and the anti-ultraviolet aging fiber can be obtained.