A device and method for determining the molecular weight of insoluble and infusible methylene aromatic polymers

Abstract

The present invention discloses a device and method for determining the molecular weight of an insoluble and infusible methylene aromatic polymer. The device is composed of a CO gas cylinder, a nitrogen gas cylinder, a vacuum pump, a double-row pipe, a pressure-resistant reaction bottle, a vacuum gauge, and a bubbler. The device can be used to determine the number average molecular weight M of an insoluble and infusible methylene aromatic polymer obtained by condensation polymerization of monochloromethylene aromatic hydrocarbon ArCH2Cl and its mixture catalyzed by a CO / Lewis acid synergistic catalytic system, which cannot be measured by conventional methods. n , and is suitable for determining the number average molecular weight M n ≤3×10 4 For polymers, when the molecular weight of the polymer exceeds this range, the relative error is large.

Description

Technical Field

[0001] The present invention relates to the determination of the molecular weight of insoluble and infusible organic high molecular substances, and in particular to a device and a method for determining the molecular weight of insoluble and infusible methylene aromatic hydrocarbon high polymers. Background Art

[0002] Polymer molecular weight is an important characterization method for polymer materials. It is closely related to the physical properties of polymer materials. It is often necessary to measure this parameter in theoretical research and production practice. There are many methods for measuring polymer molecular weight. The statistical average molecular weight obtained by different measurement methods has different meanings and is applicable to different molecular weight ranges. At present, the main test methods for the molecular weight of polymer materials include end group titration, solution colligative property method, ultracentrifugal sedimentation method, viscosity method, gel chromatography, laser light scattering method, etc.

[0003] 1. End group titration

[0004] If the polymer chain has measurable end groups and the number of end groups on each polymer is known, the number average molecular weight Mn can be obtained by performing end group analysis on a given weight of sample. The larger the polymer molecular weight, the smaller the number of end groups that can be analyzed per unit weight, and the relative error is large.

[0005] 2. Solution colligative method

[0006] The colligative properties of dilute solutions refer to the increase in boiling point, depression in freezing point, decrease in vapor pressure, and osmotic pressure of dilute solutions, which are only related to the number of solutes in the solution and have nothing to do with the nature of the solutes. The number average molecular weight Mn can be obtained by measuring the changes in the boiling point, freezing point, membrane osmotic pressure, etc. of the solution based on the colligative properties of the solution.

[0007] 3. Ultracentrifugal sedimentation method

[0008] Ultracentrifuges operate over a wide range of speeds, allowing them to measure molecular weights from sucrose to viruses. They can also measure the average molecular weight and molecular weight distribution of polydisperse macromolecules. Ultracentrifugation measures the absolute molecular weight of molecules, and does not require any standard sample for reference, nor does it require knowledge of the shape and hydration level of the sample molecules.

[0009] 4. Viscosity method

[0010] The viscosity of polymer solution is closely related to the structure of polymer, solution concentration, nature of solvent, temperature and pressure. By measuring the viscosity of dilute polymer solution, the molecular weight of polymer can be calculated, which is called viscosity average molecular weight. This method has the advantages of simple equipment, convenient operation, short measurement and data processing cycle, and high experimental accuracy.

[0011] 5. Gel Permeation Chromatography

[0012] Gel permeation chromatography, also known as size exclusion chromatography, uses porous materials to separate molecules according to their size. It is mainly used for the analysis and separation of the relative molecular mass distribution of polymers soluble in organic solvents. Gel permeation chromatography has been widely used in various fields such as industry, agriculture, medicine, health, national defense and daily life.

[0013] 6. Laser light scattering method

[0014] Light scattering is caused by photochemical inhomogeneity caused by molecular thermal motion in the medium. For polymer solutions, the intensity of scattered light is related to the molecular weight of the solute in addition to the solvent concentration. The larger the molecular weight, the greater the scattered light intensity. Therefore, light scattering can be used to measure molecular weight.

[0015] All of the above measurement methods require that the polymer be dissolved, but most of the methylene aromatic polymers obtained by the polycondensation of methylene aromatic chloride catalyzed by the CO / Lewis acid synergistic catalytic system are insoluble and infusible, and the above measurement methods cannot measure their molecular weight. Summary of the invention

[0016] The technical problem to be solved by the present invention is to provide a method for measuring the number average molecular weight M of an insoluble and infusible methylene aromatic hydrocarbon polymer obtained by condensation of methylene aromatic hydrocarbons catalyzed by a CO / Lewis acid synergistic catalytic system. n Device and method.

[0017] The technical solution adopted to solve the above technical problems is: the air inlet of the pressure-resistant reaction bottle is connected to the inside of the double-row tube through a pipeline via a double-oblique three-way piston arranged at the lower end of the double-row tube, the left end opening of the upper tube of the double-row tube is connected to the CO gas cylinder or the nitrogen gas cylinder through a three-way stopcock arranged on the pipeline, and the right end opening is connected to the bubbler through a pipeline, the left end opening of the lower tube of the double-row tube is connected to the vacuum pump through a three-way stopcock arranged on the pipeline, and the right end opening is connected to the vacuum gauge through a pipeline.

[0018] The pressure-resistant reaction bottle is a long-necked glass reaction bottle with a Teflon stopper at the bottle mouth and a safety valve processed on the bottle neck.

[0019] The pressure-resistant reaction bottle has a pressure resistance of 1×10 -7 ~0.8×10 6 Pa, temperature resistance 0~350℃, Teflon plug pressure resistance 1×10 -7 ~0.8×10 6 Pa, temperature resistance 0~160℃, maximum working pressure of safety valve 0.6×10 6 Pa.

[0020] The method for determining the molecular weight of insoluble and infusible methylene aromatic polymer using the above device is as follows:

[0021] 1. Turn on the vacuum pump, evacuate the pressure-resistant reaction bottle to below 0.2Pa, open the nitrogen bottle and introduce N2. Add m x g monomer and m l g Lewis acid catalyst, remove the pressure-resistant reaction bottle from the double-row tube, accurately weigh its mass, record it as m 前 , unit: g.

[0022] 2. Place the pressure-resistant reaction bottle in liquid nitrogen at -196°C. After the monomer and Lewis acid catalyst in the bottle are completely frozen into solid, connect the pressure-resistant reaction bottle to a double-row tube, evacuate the bottle to below 0.2 Pa at -196°C, and remove the N2 in the bottle.

[0023] 3. Open the CO gas cylinder and replace the working gas in the double-row tube with CO. The CO gas entering the pressure-resistant reaction bottle at -196°C turns into CO liquid.

[0024] 4. Remove the pressure-resistant reaction bottle from the double-row tube, return it to room temperature, and then heat it at 100-160°C for 2-6 hours to completely polycondense the monomers to obtain methylene aromatic polymers.

[0025] 5. After the reaction is completed, release the CO gas and the generated HCl gas in the pressure-resistant reaction bottle, then evacuate the pressure-resistant reaction bottle to below 0.2Pa, and then introduce N2. Remove the pressure-resistant reaction bottle from the double-row tube and accurately weigh its mass, which is recorded as m 后 , unit: g.

[0026] 6. Calculate the number average molecular weight M n

[0027] (1) When the monomer is a methylene aromatic hydrocarbon ArCH2Cl containing a chloromethylene group, wherein Ar represents any one of phenyl, C1-C4 alkyl substituted phenyl, C1-C4 alkoxy substituted phenyl, 4-phenoxyphenyl, and naphthyl, preferably any one of phenyl, 4-methylphenyl, 4-methoxyphenyl, 4-phenoxyphenyl, and naphthyl, the methylene aromatic hydrocarbon polymer H(ArCH2) is calculated according to the following formula: n The number average molecular weight of Cl is M n :

[0028]

[0029] Where m z =m 前 -m 后 , x is the amount of substance of ArCH2Cl, y is H(ArCH2) nThe amount of Cl, z is the amount of HCl produced, m is x is the mass of ArCH2Cl, m y H(ArCH2) n The mass of Cl, m z is the mass of HCl generated, M x is the molecular weight of ArCH2Cl, M n H(ArCH2) n The number average molecular weight of Cl, M z is the molecular weight of HCl.

[0030] (2) When the monomer is a mixture of two or more methylene aromatic hydrocarbons containing one chloromethylene group, the number average molecular weight M of the methylene aromatic hydrocarbon polymer is calculated according to the following formula: n :

[0031]

[0032] Where M 平均 =m 总 / n 总 , M 平均 is the average relative molecular weight, m 总 is the sum of the masses of all components in the mixture, n 总 is the sum of the molar amounts of each component in the mixture, M z is the molecular weight of HCl, m z is the mass of HCl generated.

[0033] Taking CO / Lewis acid catalyzed ArCH2Cl as an example, the principle of the present invention for determining insoluble and infusible subunit methyl aromatic polymers is as follows:

[0034]

[0035] Each polymer molecule H(ArCH2) n Cl contains only one Cl atom, and the amount of Cl in the polymer is also y. The catalyst does not participate in the reaction, and ArCH2Cl will be converted 100% into H(ArCH2) n Cl, Cl atoms are conserved before and after the reaction, and the mass is conserved, so the relationship is:

[0036] x=y+z;m x =m y +m z ;m x =xM x ;m z =zM z

[0037] Number average molecular weight M n It can be expressed as:

[0038]

[0039] M x 、M z is a known fixed value. From the above formula, we can know that the number average molecular weight M n By m x and m z The value of is determined, that is, as long as the mass m of ArCH2Cl is measured x and the mass of HCl m z Then we can get polymer H(ArCH2) n The number average molecular weight of Cl is M n .

[0040] m x It can be obtained by weighing the mass of the reactant ArCH2Cl. HCl is a gas at room temperature. After the reaction is completed, the HCl in the pressure-resistant reaction bottle is emptied. The mass change of the pressure-resistant reaction bottle can be weighed to obtain the mass of HCl m z .

[0041] When the monomer is a mixture of multiple ArCH2Cl such as Ar1CH2Cl, Ar2CH2Cl, Ar3CH2Cl, etc., the measurement principle is the same as above, and the mixture can be regarded as a "single component". The molecular weight of this "single component" is expressed by the average relative molecular weight M 平均 Meaning: M 平均 =m 总 / n 总 , m 总 is the sum of the masses of all components in the mixture, n 总 It is the sum of the molar amounts of each component in the mixture.

[0042] The number average molecular weight M of the polymer obtained by polycondensation of the mixture n It can be expressed as:

[0043]

[0044] In the above method, the Lewis acid catalyst used is a high-boiling point solid or liquid Lewis acid, specifically AlCl3, AlBr3, BCl3, H3PO4, polyphosphoric acid, or a catalyst containing BF4 - PF6 - 、SiF6 2- Alkyl imidazolium ionic liquids with isoanions.

[0045] The present invention can only measure the number average molecular weight M n , and is suitable for determining the number average molecular weight M n ≤3×10 4For polymers, when the molecular weight of the polymer exceeds this range, the relative error is large.

[0046] The present invention is only applicable to the determination of the number average molecular weight of the polymer obtained by the polycondensation of monochloromethylene aromatic hydrocarbons ArCH2Cl and their mixtures, and polyhalogenated methylene aromatic hydrocarbons Ar(CH2Cl) n (n≥2) Polymers obtained by polycondensation cannot be determined by this method n . BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a connection relationship diagram of the testing device of the present invention. DETAILED DESCRIPTION

[0048] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0049] Example 1

[0050] like Figure 1 As shown, the device for determining the molecular weight of insoluble and infusible methylene aromatic polymer in this embodiment is composed of a CO gas cylinder 1, a nitrogen gas cylinder 2, a vacuum pump 3, a double-row pipe 4, a pressure-resistant reaction bottle 5, a vacuum gauge 6, and a bubbler 7.

[0051] The air inlet of the pressure-resistant reaction bottle 5 is connected to the double-row tube 4 through a pipeline via a double-oblique three-way piston processed at the lower end of the double-row tube 4. The left end opening of the upper tube of the double-row tube 4 is connected to the CO gas cylinder 1 or the nitrogen gas cylinder 2 through a three-way plug installed on the pipeline, and the right end opening is connected to the bubbler 7 through a two-way plug installed on the pipeline. The left end opening of the lower tube of the double-row tube 4 is connected to the vacuum pump 3 through a three-way plug installed on the pipeline, and the right end opening is connected to the vacuum gauge 6 through a two-way plug installed on the pipeline.

[0052] The pressure-resistant reaction bottle 5 is a long-necked glass reaction bottle with a wall thickness of 2 mm and a volume of 350 mL. Its pressure resistance is 1×10 -7 ~0.8×10 6 Pa, temperature resistance 0 ~ 350 ℃; the mouth of the pressure-resistant reaction bottle 5 is equipped with a Teflon stopper, and the neck of the bottle is processed with a safety valve. The pressure resistance of the Teflon stopper is 1×10 -7 ~0.8×10 6 Pa, temperature resistance 0 ~ 160 ℃, the safety valve is a glass tube with a glass film, and its maximum working pressure is 0.6 × 10 6 Pa, when the pressure in the pressure-resistant reaction bottle 5 exceeds 0.6×10 6 Pa, the glass film will burst and release the pressure to ensure the safety of the reaction.

[0053] Example 2

[0054] The device of Example 1 was used to measure the polymer H(PhCH2) obtained by the synergistic condensation of benzyl chloride catalyzed by CO / ACl3 n The number average molecular weight of Cl is M n The method is as follows:

[0055]

[0056] 1. Turn on the vacuum pump 3, evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, open the nitrogen bottle 2 to introduce N2, then remove the Teflon stopcock, and add m2 into the pressure-resistant reaction bottle 5 under the protection of N2. x =3.5001g benzyl chloride and m l = 0.0250 gAlCl3 catalyst, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 前 =290.6701g.

[0057] 2. Place the pressure-resistant reaction bottle 5 in liquid nitrogen at -196°C. After the benzyl chloride and AlCl3 catalyst in the bottle are completely frozen into solid, connect the pressure-resistant reaction bottle 5 to the double-row pipe 4, evacuate the bottle to below 0.2 Pa at -196°C, and remove the N2 in the bottle.

[0058] 3. Open the CO gas cylinder 1, replace the working gas in the double-row tube 4 with CO, control the volume of the CO gas entering the pressure-resistant reaction bottle 5 to be 1100 mL, and the CO gas entering the pressure-resistant reaction bottle 5 becomes CO liquid at -196°C.

[0059] 4. Remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and after returning to room temperature, place the pressure-resistant reaction bottle 5 in an oven and heat it at 150°C for 5 hours to completely polycondense the benzyl chloride to obtain H(PhCH2) n Cl.

[0060] 5. After the reaction is completed, return to room temperature, open the Teflon stopcock in the fume hood to release the CO gas and the generated HCl gas in the pressure-resistant reaction bottle 5, then evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, then introduce N2, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 后 =289.7516g.

[0061] 6. Calculate the number average molecular weight M n

[0062] H(PhCH2) was calculated according to the following formula: n The number average molecular weight of Cl is M n :

[0063]

[0064] Where m z =m 前 -m 后 , x is the amount of benzyl chloride, y is H(PhCH2) n The amount of Cl, z is the amount of HCl produced, m is x is the mass of benzyl chloride, m y H(PhCH2) n The mass of Cl, m z is the mass of HCl generated, M x is the molecular weight of benzyl chloride, M n H(PhCH2) n The number average molecular weight of Cl, M z is the molecular weight of HCl.

[0065] Calculated H(PhCH2) n The number average molecular weight of Cl is:

[0066]

[0067] Example 3

[0068] The device of Example 1 was used to measure CO / dimethylimidazole PF6 - Polymer H(PhCH2) synthesized by condensation of benzyl chloride catalyzed by salt n The number average molecular weight of Cl is M n The method is as follows:

[0069]

[0070] 1. Turn on the vacuum pump 3, evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, open the nitrogen bottle 2 to introduce N2, then remove the Teflon stopcock, and add m2 into the pressure-resistant reaction bottle 5 under the protection of N2. x =4.000g benzyl chloride and m l =0.028g dimethylimidazole PF6 - salt, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 前 =291.1735g.

[0071] 2. Place the pressure-resistant reaction bottle 5 in liquid nitrogen at -196°C and wait for the benzyl chloride and dimethylimidazole PF6 - After the salt is completely frozen into a solid, the pressure-resistant reaction bottle 5 is connected to the double-row tube 4, and vacuum is evacuated to below 0.2 Pa at -196°C to remove the N2 in the bottle.

[0072] 3. Open the CO gas cylinder 1, replace the working gas in the double-row tube 4 with CO, control the volume of the CO gas entering the pressure-resistant reaction bottle 5 to be 1300 mL, and the CO gas entering the pressure-resistant reaction bottle 5 becomes CO liquid at -196°C.

[0073] 4. Remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and after returning to room temperature, place the pressure-resistant reaction bottle 5 in an oven and heat it at 150°C for 5 hours to completely polycondense the benzyl chloride to obtain H(PhCH2) n Cl.

[0074] 5. After the reaction is completed, return to room temperature, open the Teflon stopcock in the fume hood to release the CO gas and the generated HCl gas in the pressure-resistant reaction bottle 5, then evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, then introduce N2, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 后 =290.0305g.

[0075] 6. Calculate the number average molecular weight M n

[0076] H(PhCH2) was calculated according to the following formula: n The number average molecular weight of Cl is M n :

[0077]

[0078] Where m z =m 前 -m 后 , x is the amount of benzyl chloride, y is H(PhCH2) n The amount of Cl, z is the amount of HCl produced, m is x is the mass of benzyl chloride, m y H(PhCH2) n The mass of Cl, m z is the mass of HCl generated, M x is the molecular weight of benzyl chloride, M n H(PhCH2) n The number average molecular weight of Cl, M z is the molecular weight of HCl.

[0079] Calculated H(PhCH2) n The number average molecular weight of Cl is:

[0080]

[0081] Example 4

[0082] The device of Example 1 was used to measure CO / dimethylimidazole PF6 - Polymer H(C6H4-O-C6H4CH2) synthesized by condensation of 4-chloromethyl diphenyl ether catalyzed by salt n The number average molecular weight of Cl is M n The method is as follows:

[0083]

[0084] 1. Turn on the vacuum pump 3, evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, open the nitrogen bottle 2 to introduce N2, then remove the Teflon stopcock, and add m2 into the pressure-resistant reaction bottle 5 under the protection of N2. x =5.000g 4-chloromethyl diphenyl ether and m l =0.030g dimethylimidazole PF6 - salt, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 前 =292.1753g.

[0085] 2. Place the pressure-resistant reaction bottle 5 in liquid nitrogen at -196°C and wait for the 4-chloromethyl diphenyl ether and dimethylimidazole PF6 - After the salt is completely frozen into a solid, the pressure-resistant reaction bottle 5 is connected to the double-row tube 4, and vacuum is evacuated to below 0.2 Pa at -196°C to remove the N2 in the bottle.

[0086] 3. Open the CO gas cylinder 1, replace the working gas in the double-row tube 4 with CO, control the volume of the CO gas entering the pressure-resistant reaction bottle 5 to be 1350 mL, and the CO gas entering the pressure-resistant reaction bottle 5 becomes CO liquid at -196°C.

[0087] 4. Remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and after returning to room temperature, place the pressure-resistant reaction bottle 5 in an oven and heat it at 150°C for 5 hours to completely polycondense the benzyl chloride to obtain H(C6H4-O-C6H4CH2) n Cl.

[0088] 5. After the reaction is completed, return to room temperature, open the Teflon stopcock in the fume hood to release the CO gas and the generated HCl gas in the pressure-resistant reaction bottle 5, then evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, then introduce N2, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 后 =291.3516g.

[0089] 6. Calculate the number average molecular weight M n

[0090] H(C6H4-O-C6H4CH2) was calculated according to the following formula:n The number average molecular weight of Cl is M n :

[0091]

[0092] Where m z =m 前 -m 后 , x is the amount of 4-chloromethyl diphenyl ether, y is H(C6H4-O-C6H4CH2) n The amount of Cl, z is the amount of HCl produced, m is x is the mass of 4-chloromethyl diphenyl ether, m y H(C6H4-O-C6H4CH2) n The mass of Cl, m z is the mass of HCl generated, M x is the molecular weight of 4-chloromethyl diphenyl ether, M n H(C6H4-O-C6H4CH2) n The number average molecular weight of Cl, M z is the molecular weight of HCl.

[0093] Calculated H(C6H4-O-C6H4CH2) n The number average molecular weight of Cl is:

[0094]

[0095] Example 5

[0096] The device of Example 1 was used to measure the high polymer H(C 10 H6CH2) n The number average molecular weight of Cl is M n The method is as follows:

[0097]

[0098] 1. Turn on the vacuum pump 3, evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, open the nitrogen bottle 2 to introduce N2, then remove the Teflon stopcock, and add m2 into the pressure-resistant reaction bottle 5 under the protection of N2. x =5.100g 1-chloromethylnaphthalene and m l = 0.020 g BCl3, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 前 =292.2658g.

[0099] 2. Place the pressure-resistant reaction bottle 5 in liquid nitrogen at -196°C and wait for the 1-chloromethylnaphthalene and dimethylimidazole PF6- After the salt is completely frozen into a solid, the pressure-resistant reaction bottle 5 is connected to the double-row tube 4, and vacuum is evacuated to below 0.2 Pa at -196°C to remove the N2 in the bottle.

[0100] 3. Open the CO gas cylinder 1, replace the working gas in the double-row tube 4 with CO, control the volume of the CO gas entering the pressure-resistant reaction bottle 5 to be 1220 mL, and the CO gas entering the pressure-resistant reaction bottle 5 becomes CO liquid at -196°C.

[0101] 4. Remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and after returning to room temperature, place the pressure-resistant reaction bottle 5 in an oven and heat it at 150°C for 5 hours to completely polycondense benzyl chloride to obtain H(C 10 H6CH2) n Cl.

[0102] 5. After the reaction is completed, return to room temperature, open the Teflon stopcock in the fume hood to release the CO gas and the generated HCl gas in the pressure-resistant reaction bottle 5, then evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, then introduce N2, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 后 =291.2305g.

[0103] 6. Calculate the number average molecular weight M n

[0104] The H(C 10 H6CH2) n The number average molecular weight of Cl is M n :

[0105]

[0106] Where m z =m 前 -m 后 , x is the amount of 1-chloromethylnaphthalene, y is H(C 10 H6CH2) n The amount of Cl, z is the amount of HCl produced, m is x is the mass of 1-chloromethylnaphthalene, m y H(C 10 H6CH2) n The mass of Cl, m z is the mass of HCl generated, M x is the molecular weight of 1-chloromethylnaphthalene, M n H(C 10 H6CH2) n The number average molecular weight of Cl, M z is the molecular weight of HCl.

[0107] Calculate H(C 10 H6CH2) n The number average molecular weight of Cl is:

[0108]

[0109] Example 6

[0110] The device of Example 1 was used to measure CO / dimethylimidazole PF6 - Polymer H[C6H3(OCH3)CH2] synthesized by condensation of 4-methoxybenzyl chloride catalyzed by salt n The number average molecular weight of Cl is M n The method is as follows:

[0111]

[0112] 1. Turn on the vacuum pump 3, evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, open the nitrogen bottle 2 to introduce N2, then remove the Teflon stopcock, and add m2 into the pressure-resistant reaction bottle 5 under the protection of N2. x = 4.200 g 4-methoxybenzyl chloride and m l =0.033g dimethylimidazole PF6 - salt, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 前 =291.3787g.

[0113] 2. Place the pressure-resistant reaction bottle 5 in liquid nitrogen at -196°C and wait for the 4-methoxybenzyl chloride and dimethylimidazole PF6 - After the salt is completely frozen into a solid, the pressure-resistant reaction bottle 5 is connected to the double-row tube 4, and vacuum is evacuated to below 0.2 Pa at -196°C to remove the N2 in the bottle.

[0114] 3. Open the CO gas cylinder 1, replace the working gas in the double-row tube 4 with CO, control the volume of the CO gas entering the pressure-resistant reaction bottle 5 to be 1300 mL, and the CO gas entering the pressure-resistant reaction bottle 5 becomes CO liquid at -196°C.

[0115] 4. Remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and after returning to room temperature, place the pressure-resistant reaction bottle 5 in an oven and heat it at 150°C for 5 hours to completely polycondense the benzyl chloride to obtain H[C6H3(OCH3)CH2] n Cl.

[0116] 5. After the reaction is completed, return to room temperature, open the Teflon stopcock in the fume hood to release the CO gas and the generated HCl gas in the pressure-resistant reaction bottle 5, then evacuate the pressure-resistant reaction bottle 5 to below 0.2 Pa, then introduce N2, close the Teflon stopcock, remove the pressure-resistant reaction bottle 5 from the double-row tube 4, and accurately weigh its mass m 后 =290.4105g.

[0117] 6. Calculate the number average molecular weight M n

[0118] H[C6H3(OCH3)CH2] was calculated according to the following formula: n The number average molecular weight of Cl is M n :

[0119]

[0120] Where m z =m 前 -m 后 , x is the amount of 4-methoxybenzyl chloride, y is H[C6H3(OCH3)CH2] n The amount of Cl, z is the amount of HCl produced, m is x is the mass of 4-methoxybenzyl chloride, m y H[C6H3(OCH3)CH2] n The mass of Cl, m z is the mass of HCl generated, M x is the molecular weight of 4-methoxybenzyl chloride, M n H[C6H3(OCH3)CH2] n The number average molecular weight of Cl, M z is the molecular weight of HCl.

[0121] Calculated H[C6H3(OCH3)CH2] n The number average molecular weight of Cl is:

[0122]

Claims

1. A method for determining the molecular weight of an insoluble and infusible methylene aromatic polymer, characterized in that: The structure of the measuring device used in the method is as follows: the air inlet of the pressure-resistant reaction bottle (5) is connected to the inside of the double-row tube (4) through a pipeline via a double-inclined three-way piston arranged at the lower end of the double-row tube (4); the left end opening of the upper tube of the double-row tube (4) is connected to the CO gas cylinder (1) or the nitrogen gas cylinder (2) through a three-way cock arranged on the pipeline, and the right end opening is connected to the bubbler (7) through a pipeline; the left end opening of the lower tube of the double-row tube (4) is connected to the vacuum pump (3) through a three-way cock arranged on the pipeline, and the right end opening is connected to the vacuum gauge (6) through a pipeline; The method comprises the following steps: Step 1: Turn on the vacuum pump (3) to evacuate the pressure-resistant reaction bottle (5) to below 0.2 Pa, then open the nitrogen bottle (2) to introduce N2, and add m into the pressure-resistant reaction bottle (5) under the protection of N2. x g monomer and m l g Lewis acid catalyst, remove the pressure-resistant reaction bottle (5) from the double-row tube (4), accurately weigh its mass, record it as m 前 , unit: g; Step 2: Place the pressure-resistant reaction bottle (5) in liquid nitrogen at -196°C. After the monomer and Lewis acid catalyst in the bottle are completely frozen into solid, connect the pressure-resistant reaction bottle (5) to the double-row tube (4), evacuate the pressure-resistant reaction bottle to below 0.2 Pa at -196°C, and remove the N2 in the bottle; Step 3: Open the CO gas cylinder (1), replace the working gas in the double-row tube (4) with CO, and the CO gas entering the pressure-resistant reaction bottle (5) at -196°C turns into CO liquid; Step 4: removing the pressure-resistant reaction bottle (5) from the double-row tube (4), returning the bottle to room temperature, and then heating the bottle at 100 to 160° C. for 2 to 6 hours to completely polycondense the monomers to obtain a methylene aromatic polymer; Step 5: After the reaction is completed, the CO gas and the generated HCl gas in the pressure-resistant reaction bottle (5) are released, and then the pressure-resistant reaction bottle (5) is evacuated to below 0.2 Pa, and then N2 is introduced. The pressure-resistant reaction bottle (5) is removed from the double-row tube (4), and its mass is accurately weighed and recorded as m 后 , unit: g; Step 6: Calculate the number average molecular weight M n ① When the monomer is a methylene aromatic hydrocarbon ArCH2Cl containing a chloromethylene group, wherein Ar represents any one of phenyl, C1-C4 alkyl substituted phenyl, C1-C4 alkoxy substituted phenyl, 4-phenoxyphenyl, and naphthyl, the methylene aromatic hydrocarbon polymer H(ArCH2) is calculated according to the following formula: n The number average molecular weight of Cl is M n : Where m z =m 前 -m 后 , x is the amount of substance of ArCH2Cl, y is H(ArCH2) n The amount of Cl, z is the amount of HCl produced, m is x is the mass of ArCH2Cl, m y H(ArCH2) n The mass of Cl, m z is the mass of HCl generated, M x is the molecular weight of ArCH2Cl, M n H(ArCH2) n The number average molecular weight of Cl, M z is the molecular weight of HCl; ② When the monomer is a mixture of two or more methylene aromatic hydrocarbons containing one chloromethylene group, the number average molecular weight M of the methylene aromatic hydrocarbon polymer is calculated according to the following formula: n : Where M 平均 =m 总 / n 总 , M 平均 is the average relative molecular weight, m 总 is the sum of the masses of all components in the mixture, n 总 is the sum of the molar amounts of each component in the mixture, M z is the molecular weight of HCl, m z is the mass of HCl generated.

2. The method for determining the molecular weight of an insoluble and infusible methylene aromatic polymer according to claim 1, characterized in that: The pressure-resistant reaction bottle (5) is a long-necked glass reaction bottle with a Teflon stopper at the bottle mouth and a safety valve processed on the bottle neck.

3. The method for determining the molecular weight of an insoluble and infusible methylene aromatic polymer according to claim 2, characterized in that: The pressure-resistant reaction bottle (5) has a pressure resistance of 1×10 -7 ~0.8×10 6 Pa, temperature resistance 0~350℃, Teflon plug pressure resistance 1×10 -7 ~0.8×10 6 Pa, temperature resistance 0~160℃, maximum working pressure of safety valve 0.6×10 6 Pa.

4. The method for determining the molecular weight of an insoluble and infusible methylene aromatic polymer according to claim 1, characterized in that: The Ar represents any one of phenyl, 4-methylphenyl, 4-methoxyphenyl, 4-phenoxyphenyl and naphthyl.

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