A quantitative method for trace silanol in MQ silicone resin

Abstract

The present invention discloses a method for quantitatively determining trace silanol groups in MQ silicone resin. The method of the present invention firstly removes water from a non-polar organic solvent, and uses an anhydrous non-polar solvent to prepare an MQ silicone resin solution from an MQ silicone resin; a derivatization agent and a catalyst are added to the MQ silicone resin solution to perform a derivatization reaction; after the reaction is completed, a base is added to the reaction system to convert the excess derivatization agent into a polar substance insoluble in the non-polar solvent, and a derivatization product is obtained after filtering; the derivatization product is subjected to gel permeation chromatography ultraviolet GPC-UV analysis, and an external standard method is used to quantify trace silanol groups in MQ silicone resin. The method of the present invention has mild reaction conditions, fast reaction speed, and the reaction product has good stability and ultraviolet absorption. The method of the present invention has high sensitivity, good selectivity and accuracy, relatively low analysis cost, and a wide range of application fields.

Description

Technical Field

[0001] The invention belongs to a detection technology method, and specifically relates to a quantitative method for trace silanol groups in methyl (or methyl vinyl) MQ silicone resin based on chemical derivatization and gel permeation chromatography ultraviolet analysis (GPC-UV). Background Art

[0002] MQ silicone resin (MQ resin for short) is a double-layer spherical silicone resin, which consists of a single functional group R 3 It is composed of Si-O unit (M unit) and internal four-functional Si-O unit (Q unit). According to the needs of different fields, silicone resins with different functional groups are synthesized, such as methyl, vinyl, amino, hydrogen-containing, phenyl silicone resins, etc. MQ silicone resin has great application value in industry. It is mainly used as reinforcing filler for addition-type liquid silicone rubber, filler and tackifier for silicone pressure-sensitive adhesive, which depends on its excellent mechanical properties, excellent heat resistance, electrical insulation, weather resistance, flexibility, film-forming and adhesion. As the active group in MQ silicone resin, even if the content is very low, silanol will directly affect the physical and chemical properties of its subsequent processed polysiloxane products. The hydroxyl content is an important indicator of the reinforcement effect in MQ silicone resin. When the hydroxyl content decreases, the tensile strength (i.e. mechanical properties) of silicone rubber is weakened, the degree of chemical bonding between silicone resin and silicone rubber increases (good compatibility), the light transmittance increases, and the conductivity decreases. Only when the mass fraction of silanol is appropriate, the reinforcement effect is the best. Therefore, the accurate determination of the silanol content in MQ silicone resin is of great value to the performance regulation and quality improvement of related products.

[0003] The patent application with publication number CN104391073A discloses a method for determining the hydroxyl value of hydroxyl silicone oil and hydroxyl fluorosilicone oil. The determination method is: let the terminal hydroxyl silicone molecules undergo condensation reaction under the action of catalysts such as sodium silanol, collect the water produced by the condensation of the terminal hydroxyl groups through a water absorbent, and convert the hydroxyl value of the terminal hydroxyl silicone molecules. This determination method actually determines the total content of hydroxyl groups in small molecules such as water and alcohols in the organosilicon molecule sample. Trace water, alcohols and other hydroxyl-containing compounds in silicone oil products, and trace water in the air absorbed by sodium alkoxide will seriously interfere with the determination of the content of silanol. At the same time, this method requires oil bath heating and is difficult to apply to the determination of trace water.

[0004] The patent application with publication number CN110988255A discloses a method for determining the silanol value of terminal hydroxyl organic silicon. The invention method is applicable to the determination of the silanol value in terminal hydroxyl organic silicon compounds such as terminal hydroxyl silicone oil, terminal hydroxyl fluorosilicone oil, and polyether modified silicone oil. The invention uses an organic bismuth catalyst to allow excess isocyanate to undergo a polycondensation reaction with terminal hydroxyl organic silicon, and calculates the terminal hydroxyl organic silicon value by measuring the content of residual isocyanate groups. However, the detection sensitivity of this method is not high enough, and it is also impossible to eliminate the interference of trace water in the sample and the environment on the determination of silanol.

[0005] Chinese patent document CN112505203B discloses a method for determining the silanol value in hydroxy silicone oil: using aromatic chlorosilane to stoichiometrically convert the silanol in hydroxy silicone oil into a group that can be sensitively detected by UV, and then using gel permeation chromatography ultraviolet detection (GPC-UV) to analyze the derivatized product and quantify the silanol. This method eliminates the interference of trace water, alcohols and other small molecule compounds containing hydroxyl groups on the quantification of silanol, and greatly improves the sensitivity of silanol detection. However, this method is not very suitable for the determination of trace silanol in MQ silicone resin. This is because the molecular weight of MQ silicone resin is relatively small, and the derivatization product of MQ silicone resin and the derivatization reagent are difficult to be effectively separated on the GPC column, thereby affecting the quantification of trace silanol in MQ silicone resin. Summary of the invention

[0006] The purpose of the present invention is to provide a method for quantifying trace amounts of silanol groups in MQ silicone resin.

[0007] The method of the present invention specifically comprises:

[0008] Step (1) A non-polar organic solvent is added with a dehydrating agent for dehydration treatment, and an MQ silicone resin is prepared into an MQ silicone resin solution with a concentration of 0.1 to 100 g / L using an anhydrous non-polar solvent, wherein the MQ silicone resin is methyl MQ silicone resin or methyl vinyl MQ silicone resin.

[0009] Furthermore, the non-polar solvent is one of C5-C12 alkanes, tetrahydrofuran, xylene, and methyl tert-butyl ether. Furthermore, the non-polar solvent is n-hexane or tetrahydrofuran. The alkanes are inert solvents that do not contain any functional groups, have almost no ultraviolet absorption, have little interference with ultraviolet detection, are easy to detect by ultraviolet, and are not easy to volatilize.

[0010] Furthermore, the dehydrating agent is a neutral molecular sieve, a sodium block, anhydrous sodium sulfate or anhydrous calcium chloride, the dosage of the dehydrating agent is 1 to 10% of the mass of the non-polar organic solvent, and the dehydration time is 48 to 72 hours.

[0011] Furthermore, the concentration of the MQ silicone resin solution is 1 to 20 g / L.

[0012] Step (2) adding a derivatization agent and a catalyst to the MQ silicone resin solution to carry out a derivatization reaction for a reaction time of 0.5 to 6 hours.

[0013] Furthermore, the derivatization reagent is one of benzoyl chloride, methylbenzoyl chloride, chlorobenzoyl chloride, methoxybenzoyl chloride, and N,N-dimethylbenzoyl chloride, and the mass ratio of the added derivatization reagent to the MQ silicone resin is 1 to 100:1.

[0014] Taking benzoyl chloride as an example, the derivatization reaction equation is as follows:

[0015]

[0016] Furthermore, the catalyst is one of 1-methylimidazole, 2-methylimidazole, 4-methylimidazole, cyclohexylamine, 2-aminopyridine, 3-aminopyridine, and 4-dimethylaminopyridine, and the mass ratio of the added catalyst to the MQ silicone resin is 0.01 to 0.1:1.

[0017] After the reaction in step (3) is completed, a base is added to the reaction system to convert the excess derivatization reagent into a polar substance insoluble in the non-polar solvent, and the derivatization product is obtained after filtering.

[0018] Furthermore, the base is ammonia water, triethylamine or sodium carbonate.

[0019] Step (4) performs gel permeation chromatography (GPC-UV) analysis on the derivatized product and uses an external standard method to quantify the trace silanol groups in the MQ silicone resin.

[0020] Furthermore, the gel permeation chromatography ultraviolet GPC-UV analysis instrument is a liquid chromatograph, with a gel permeation chromatography column as a separation column, and a detector being an ultraviolet detector, a diode array detector or a fluorescence detector.

[0021] Furthermore, the gel permeation chromatography ultraviolet GPC-UV analysis uses tetrahydrofuran as the eluent. When the external standard method is used for quantification, methyl benzoate is used as the standard substance. The ultraviolet detection wavelength is set to 250-270 nm.

[0022] The method of the present invention adopts the phenyl chloride derivatization method combined with GPC-UV analysis for the first time, and establishes a sensitive quantitative method for trace silanol in methyl (or methyl vinyl) MQ silicone resin. The derivatization product of MQ silicone resin belongs to a macromolecular compound, and the reaction product of small molecules in the MQ silicone resin sample, such as water, alcohols, etc., and the derivatization reagent is a small molecular compound, and the two are easily separated on the GPC column, so the interference of small molecules such as water on the detection of silanol in MQ silicone resin can be eliminated. Under the action of the catalyst, the benzoyl chloride derivatization reaction conditions are mild and the reaction speed is fast; the reaction product has good stability and ultraviolet absorption, so that the analytical method has excellent sensitivity, selectivity and accuracy. The derivatization reagent practical for the method of the present invention can be directly obtained from the market, and can react quickly and efficiently with silanol. Excess benzoyl chloride in the reaction can be hydrolyzed or reacted with an alkali to generate a polar product insoluble in non-polarity, which can be directly filtered and removed, thereby reducing the interference with the GPC-UV analysis of the MQ silicone resin derivative product. The analytical instrument used in the method of the present invention adopts an ordinary liquid chromatography combined with a spectrum GPC chromatographic column, and the analysis cost is relatively low. The method of the invention can be used for quantitative detection of trace silanol groups in various methyl (or methyl vinyl ester) MQ silicone resin products, and has a very wide range of application fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is the GPC-UV diagram of the standard sample in Example 21;

[0024] Figure 2 is the quantitative working curve of silanol obtained by liquid chromatography analysis in Example 22;

[0025] Figure 3 is the GPC-UV chromatogram of the acylation product of methyl MQ silicone resin 1 in Example 23;

[0026] Figure 4 is the GPC-UV chromatogram of the acylation product of methyl MQ silicone resin 2 in Example 24;

[0027] Figure 5 is the GPC-UV chromatogram of the acylation product of methyl vinyl MQ silicone resin 1 in Example 25;

[0028] Figure 6 This is the GPC-UV chromatogram of the acylation product of methyl vinyl MQ silicone resin 2 in Example 26. DETAILED DESCRIPTION

[0029] Example 1. Preparation of MQ silicone resin solution:

[0030] The n-hexane solvent is added to the neutral molecular sieve for dehydration treatment, the amount of the neutral molecular sieve is 5% of the mass of the n-hexane solvent, and the dehydration time is 60 hours. The methyl MQ silicone resin is prepared into an MQ silicone resin solution with a concentration of 1g / L using an anhydrous non-polar solvent.

[0031] Example 2. Preparation of MQ silicone resin solution:

[0032] Tetrahydrofuran solvent was added to sodium block for dehydration treatment, the amount of sodium block used was 9% of the mass of n-hexane solvent, and the dehydration time was 48 hours. Methyl vinyl MQ silicone resin was prepared into MQ silicone resin solution with a concentration of 5g / L using an anhydrous non-polar solvent.

[0033] Example 3. Preparation of MQ silicone resin solution:

[0034] The n-hexane solvent was added with anhydrous sodium sulfate for dehydration treatment, the amount of anhydrous sodium sulfate used was 8% of the mass of the n-hexane solvent, and the dehydration time was 70 hours. The methyl MQ silicone resin was prepared into an MQ silicone resin solution with a concentration of 10 g / L using an anhydrous non-polar solvent.

[0035] Example 4. Preparation of MQ silicone resin solution:

[0036] The tetrahydrofuran solvent is added with anhydrous calcium chloride for dehydration treatment, the amount of anhydrous calcium chloride used is 10% of the mass of the n-hexane solvent, and the dehydration time is 48 hours. The methyl vinyl MQ silicone resin is prepared into an MQ silicone resin solution with a concentration of 15g / L using an anhydrous non-polar solvent.

[0037] Example 5. Preparation of MQ silicone resin solution:

[0038] The n-pentane solvent was added with anhydrous sodium sulfate for dehydration treatment, the amount of anhydrous sodium sulfate used was 5% of the mass of the n-hexane solvent, and the dehydration time was 54 hours. The methyl MQ silicone resin was prepared into an MQ silicone resin solution with a concentration of 20 g / L using an anhydrous non-polar solvent.

[0039] Example 6. Preparation of MQ silicone resin solution:

[0040] The n-heptane solvent was added with anhydrous calcium chloride for dehydration treatment, the amount of anhydrous calcium chloride used was 4% of the mass of the n-hexane solvent, and the dehydration time was 60 hours. The methyl vinyl MQ silicone resin was prepared into a MQ silicone resin solution with a concentration of 50 g / L using an anhydrous non-polar solvent.

[0041] Example 7. Preparation of MQ silicone resin solution:

[0042] The n-dodecane solvent was added to the neutral molecular sieve for dehydration treatment, the amount of the neutral molecular sieve was 3% of the mass of the n-hexane solvent, and the dehydration time was 66 hours. The methyl MQ silicone resin was prepared into a MQ silicone resin solution with a concentration of 100 g / L using an anhydrous non-polar solvent.

[0043] Example 8. Preparation of MQ silicone resin solution:

[0044] The xylene solvent was added to the neutral molecular sieve for dehydration treatment, the amount of the neutral molecular sieve was 2% of the mass of the n-hexane solvent, and the dehydration time was 70 hours. The methyl vinyl MQ silicone resin was prepared into a MQ silicone resin solution with a concentration of 0.1 g / L using an anhydrous non-polar solvent.

[0045] Example 9. Preparation of MQ silicone resin solution:

[0046] Methyl tert-butyl ether solvent was added to sodium block for dehydration treatment, the amount of sodium block used was 1% of the mass of n-hexane solvent, and the dehydration time was 72 hours. Methyl MQ silicone resin was prepared into MQ silicone resin solution with a concentration of 0.5 g / L using an anhydrous non-polar solvent.

[0047] The derivatization reaction is carried out using the MQ silicone resin solution prepared in any one of Examples 1 to 9.

[0048] Example 10. Derivatization reaction:

[0049] Benzoyl chloride and catalyst 1-methylimidazole were added to the MQ silicone resin solution to carry out a derivatization reaction. The mass ratio of the added benzoyl chloride to the MQ silicone resin in the MQ silicone resin solution was 1:1, the mass ratio of the added 1-methylimidazole to the MQ silicone resin in the MQ silicone resin solution was 0.01:1, and the reaction time was 6 hours.

[0050] Example 11. Derivatization reaction:

[0051] Anthoxybenzoyl chloride and catalyst 2-methylimidazole were added to the MQ silicone resin solution to carry out a derivatization reaction, the mass ratio of the added methoxybenzoyl chloride to the MQ silicone resin in the MQ silicone resin solution was 10:1, the mass ratio of the added 2-methylimidazole to the MQ silicone resin in the MQ silicone resin solution was 0.08:1, and the reaction time was 1 hour.

[0052] Example 12. Derivatization reaction:

[0053] Benzoyl chloride and catalyst 4-methylimidazole were added to the MQ silicone resin solution to carry out a derivatization reaction. The mass ratio of the added benzoyl chloride to the MQ silicone resin in the MQ silicone resin solution was 20:1, the mass ratio of the added 4-methylimidazole to the MQ silicone resin in the MQ silicone resin solution was 0.06:1, and the reaction time was 2 hours.

[0054] Example 13. Derivatization reaction:

[0055] Chlorobenzoyl chloride and catalyst cyclohexylamine were added to the MQ silicone resin solution to carry out a derivatization reaction, the mass ratio of the added chlorobenzoyl chloride to the MQ silicone resin in the MQ silicone resin solution was 100:1, the mass ratio of the added cyclohexylamine to the MQ silicone resin in the MQ silicone resin solution was 0.1:1, and the reaction time was 0.5 hour.

[0056] Example 14. Derivatization reaction:

[0057] Methylbenzoyl chloride and catalyst 2-aminopyridine were added to the MQ silicone resin solution to carry out a derivatization reaction. The mass ratio of the added methylbenzoyl chloride to the MQ silicone resin in the MQ silicone resin solution was 50:1, the mass ratio of the added 2-aminopyridine to the MQ silicone resin in the MQ silicone resin solution was 0.05:1, and the reaction time was 3 hours.

[0058] Example 15. Derivatization reaction:

[0059] N,N-dimethylbenzoyl chloride and catalyst 3-aminopyridine were added to the MQ silicone resin solution to carry out a derivatization reaction. The mass ratio of the added N,N-dimethylbenzoyl chloride to the MQ silicone resin in the MQ silicone resin solution was 5:1, the mass ratio of the added 3-aminopyridine to the MQ silicone resin in the MQ silicone resin solution was 0.06:1, and the reaction time was 4 hours.

[0060] Example 16. Derivatization reaction:

[0061] Methylbenzoyl chloride and catalyst 4-dimethylaminopyridine were added to the MQ silicone resin solution to carry out a derivatization reaction, the mass ratio of the added methylbenzoyl chloride to the MQ silicone resin in the MQ silicone resin solution was 80:1, the mass ratio of the added 4-dimethylaminopyridine to the MQ silicone resin in the MQ silicone resin solution was 0.02:1, and the reaction time was 5 hours.

[0062] After the derivatization reaction of any one of Examples 10 to 16 is completed, the following treatment is performed:

[0063] Example 17.

[0064] Ammonia water is added to the reaction system to convert the excess derivatization reagent into a polar substance insoluble in the non-polar solvent, and the derivatization product is obtained after filtering.

[0065] Example 18.

[0066] Triethylamine is added to the reaction system to convert the excess derivatization reagent into a polar substance insoluble in the non-polar solvent, and the derivatization product is obtained after filtration.

[0067] Example 19.

[0068] Sodium carbonate is added to the reaction system to convert the excess derivatization reagent into a polar substance insoluble in the non-polar solvent, and the derivatization product is obtained after filtering.

[0069] Example 20.

[0070] The derivatized product prepared in any of the above embodiments is subjected to gel permeation chromatography ultraviolet (GPC-UV) analysis, and the trace silanol groups in the MQ silicone resin are quantified using an external standard method.

[0071] The Gel Permeation Chromatography UV GPC-UV analysis instrument is a liquid chromatograph, with a gel permeation chromatography column as the separation column, and a UV detector, a diode array detector or a fluorescence detector. Tetrahydrofuran is used as the eluent for the Gel Permeation Chromatography UV GPC-UV analysis. When the external standard method is used for quantification, methyl benzoate is selected as the standard. The UV detection wavelength is set to 250-270nm.

[0072] Example 21. Preparation of working curve for silanol detection:

[0073] A 5000nmol / mL methyl benzoate standard stock solution was prepared, and the phenyl concentration in the stock solution was calculated to be 5000nmol / mL according to the silanol concentration measured in the embodiment. The standard stock solution was diluted stepwise by 5 times, 10 times, 50 times, 100 times, and 500 times to prepare a standard solution series, and the corresponding phenyl concentrations were 1000nmol / mL, 500nmol / mL, 100nmol / mL, 50nmol / mL, and 10nmol / mL, respectively.

[0074] The above series of standard solutions were subjected to GPC-UV analysis (such as Figure 1 The results show that the detection limit is 5.0nmol / mL and the quantification limit is 10.0nmol / mL. Among them, phenyl is derived from silanol, so the phenyl concentration can be equivalently calculated as the silanol concentration. The working curve of the peak area versus phenyl concentration (i.e. silanol concentration) is as follows: Figure 2 The relevant working curve data are summarized in the following table (regression equation, correlation coefficient and linear range of quantitative analysis of silanol).

[0075]

[0076] Example 22. Detection of silanol content of methyl MQ silicone resin sample 1:

[0077] Take MQ silicone resin sample 1 and dissolve it in anhydrous tetrahydrofuran to prepare 2 mg / mL sample stock solution 1. Take 1 mL of stock solution 1, add 30 μL of benzoyl chloride reagent and 30 μL of cyclohexylamine solution (1 mg / mL), stir and react for 4 hours at 40°C, then add 20 μL of triethylamine and stir and react for 0.5 hours. After filtering the derivatized product solution 1 with a 0.45 μm organic filter membrane, directly perform GPC-UV analysis. The liquid chromatogram of the derivatized product of MQ silicone resin sample 1 is shown in Figure 3 As shown in the figure, the retention time of the derivatized product is 8.47 min and the peak area is 2782. The test results are substituted into the standard working curve and the silanol content of the MQ silicone resin sample is calculated to be 1.53 mg / g.

[0078] Example 23: Detection of silanol content of methyl MQ silicone resin sample 2:

[0079] Take methyl MQ silicone resin sample 2 and dissolve it in anhydrous tetrahydrofuran to prepare 2 mg / mL sample stock solution 2. Take 1 mL of stock solution 2, add 30 μL of benzoyl chloride reagent and 30 μL of 1-methylimidazole solution (1 mg / mL), stir and react at 40°C for 4 hours, then add 20 μL of triethylamine and stir and react for 2.0 hours. After filtering the acylated product solution 2 with a 0.45 μm organic filter membrane, directly perform GPC-UV analysis. The liquid chromatogram of the acylated product of methyl MQ silicone resin sample 2 is shown in Figure 4 As shown in the figure, the retention time of the derivatized product is 8.24 min and the peak area is 3372. The test results are substituted into the standard working curve and the silanol content of the MQ silicone resin sample is calculated to be 1.86 mg / g.

[0080] Example 24. Detection of silanol content of methyl vinyl MQ silicone resin sample 3:

[0081] Take methyl vinyl MQ silicone resin sample 3 and dissolve it in anhydrous tetrahydrofuran to prepare 2 mg / mL sample stock solution 3. Take 1 mL of stock solution 3, add 200 μL of benzoyl chloride reagent and 30 uL of 2-methylimidazole solution (1 mg / mL), stir and react at 40°C for 4 hours, then add 20 μL of triethylamine and stir and react for 1.5 hours. After filtering the acylated product solution 3 using a 0.45 μm organic filter membrane, directly perform GPC-UV analysis. The liquid chromatogram of the acylated product of methyl vinyl MQ silicone resin sample 3 is shown in Figure 2. Figure 5 As shown in the figure, the retention time of the derivatized product is 8.37 min and the peak area is 4107. The test results are substituted into the standard working curve and the silanol content of the MQ silicone resin sample is calculated to be 2.88 mg / g.

[0082] Example 25. Detection of silanol content of methyl vinyl MQ silicone resin sample 4:

[0083] Take methyl vinyl MQ silicone resin sample 4 and dissolve it in anhydrous tetrahydrofuran to prepare 2 mg / mL sample stock solution 4. Take 1 mL of stock solution 4, add 200 μL of benzoyl chloride reagent and 30 μL of 4-dimethylaminopyridine solution (1 mg / mL), stir and react at 40°C for 4 hours, then add 20 μL of triethylamine and stir and react for 3.0 hours. After filtering the acylated product solution 4 using a 0.45 μm organic filter membrane, directly perform GPC-UV analysis. The liquid chromatogram of the acylated product of methyl vinyl MQ silicone resin sample 4 is shown in FIG. Figure 6 As shown in the figure, the retention time of the derivatized product is 8.68 min and the peak area is 3493. The test results are substituted into the standard working curve and the silanol content of the MQ silicone resin sample is calculated to be 1.93 mg / g.

Claims

1. A method for quantitative determination of trace silanol groups in MQ silicone resin, wherein the MQ silicone resin is methyl MQ silicone resin or methyl vinyl MQ silicone resin; characterized in that: Step (1) A dehydrating agent is added to a non-polar organic solvent for dehydration treatment, and an MQ silicone resin is prepared into an MQ silicone resin solution with a concentration of 0.1 to 100 g / L using an anhydrous non-polar solvent; the non-polar solvent is one of C5 to C12 alkanes, tetrahydrofuran, xylene, and methyl tert-butyl ether; the dehydrating agent is a neutral molecular sieve, a sodium block, anhydrous sodium sulfate or anhydrous calcium chloride, the amount of the dehydrating agent is 1 to 10% of the mass of the non-polar organic solvent, and the dehydration time is 48 to 72 hours; Step (2) adding a derivatization agent and a catalyst to the MQ silicone resin solution to carry out a derivatization reaction for 0.5 to 6 hours; The derivatization reagent is one of benzoyl chloride, methylbenzoyl chloride and methoxybenzoyl chloride, and the mass ratio of the added derivatization reagent to the MQ silicone resin is 1 to 100:1; The catalyst is one of 1-methylimidazole, cyclohexylamine and 2-aminopyridine, and the mass ratio of the added catalyst to the MQ silicone resin is 0.01-0.1:1; After the reaction in step (3) is completed, a base is added to the reaction system to convert the excess derivatization reagent into a polar substance insoluble in the non-polar solvent, and the derivatization product is obtained after filtering; Step (4) GPC-UV analysis is performed on the derivatized product, and the trace silanol groups in the MQ silicone resin are quantified by an external standard method, with methyl benzoate being selected as the standard substance; tetrahydrofuran is used as the eluent for the GPC-UV analysis, and the UV detection wavelength is set to 250-270 nm.

2. A method for quantitative determination of trace silanol groups in MQ silicone resin as claimed in claim 1, characterized in that: The base described in step (3) is aqueous ammonia, triethylamine or sodium carbonate.

3. A method for quantitative determination of trace silanol groups in MQ silicone resin as claimed in claim 1, characterized in that: In step (4), the gel permeation chromatography ultraviolet GPC-UV analysis instrument is a liquid chromatograph, a gel permeation chromatography column is used as a separation column, and a detector is a UV detector.

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