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Analysis method of cross-linking degree of moisture-curable polyurethane

An analytical method and polyurethane technology, applied in the field of polymer chemistry, can solve problems such as large errors, complicated prepolymerization and curing processes, and inability to accurately test the cross-linking reaction ratio.

Active Publication Date: 2017-05-10
GUANGZHOU BAIYUN CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This test method only tests the degree of cross-linking of EVA packaging materials at a single temperature range, and the cross-linking reaction in EVA packaging materials is not one, this method cannot accurately test the proportion of various cross-linking reactions, and the error is large
[0006] In summary, the actual prepolymerization and curing process of moisture-curing polyurethane adhesives is very complicated, and its cross-linking structure and degree of cross-linking play a decisive role in performance, but there is no effective method to characterize it at this stage, so currently only through Try to improve the formula to meet certain performance requirements

Method used

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  • Analysis method of cross-linking degree of moisture-curable polyurethane
  • Analysis method of cross-linking degree of moisture-curable polyurethane

Examples

Experimental program
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Effect test

Embodiment 1

[0066] A method for analyzing the degree of crosslinking of moisture-cured polyurethane, said method comprising the following steps:

[0067] (1) The moisture-cured polyurethane sample is packed into an iron mesh bag, and the seal is obtained to obtain a test sample;

[0068] (2) Put the test sample obtained in step (2) into the extraction device equipped with NMP, respectively in the first temperature section 85°C, the second temperature section 110°C, the third temperature section 120°C and the fourth temperature section 200°C, extract the test sample for 8 hours, dry the test sample after the extraction, and weigh it;

[0069] (3) According to the formula C=(m 2 -m 0 ) / (m 1 -m 0 ) to calculate the degree of cross-linking of the test sample;

[0070] Wherein, C is the degree of cross-linking of the test sample in the formula, m 2 is the quality of the test sample after extraction in each temperature section, m1 is the quality of the test sample in advance of extraction...

Embodiment 2

[0073] A method for analyzing the degree of crosslinking of moisture-cured polyurethane, said method except that the raw materials of moisture-cured polyurethane are cured for 7 days at 15° C. and 30% RH after prepolymerization, and other conditions are the same as in Example 1.

Embodiment 3

[0075] A method for analyzing the crosslinking degree of moisture-cured polyurethane, except that the raw material prepolymerization temperature of moisture-cured polyurethane is 100°C, other conditions are the same as in Example 1.

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Abstract

The invention relates to an analysis method of the cross-linking degree of moisture-curable polyurethane. The method comprises the following steps: feeding a moisture-curable polyurethane sample into a net-shaped covering object and sealing to obtain a testing sample; putting the obtained testing sample into an extraction device filled with a solvent; extracting the testing sample at a first temperature range of 60 DEG C to 90 DEG C, a second temperature range of 100 DEG C to 110 DEG C, a third temperature range of 120 DEG C to 130 DEG C and a fourth temperature range of 140 DEG C to 260 DEG C; after extracting, drying the testing sample and weighing; calculating the cross-linking degree of the testing sample according to an equation C=(m2-m0) / (m1-m0). According to the analysis method, the testing sample is extracted under the four different temperature ranges and is calculated, so that a cross-linking type and a ratio in the moisture-curable polyurethane are analyzed, and furthermore, performances of the moisture-curable polyurethane are analyzed; the analysis method has certain guidance meanings on formula, process and utilization condition selection of a moisture-curable polyurethane adhesive product.

Description

technical field [0001] The invention belongs to the field of macromolecule chemistry and relates to an analysis method for the crosslinking degree of moisture-cured polyurethane. Background technique [0002] The moisture-curing polyurethane adhesive contains active NCO groups. When it is exposed to the air, it can react with trace moisture in the air; The hydrogen group reacts chemically to form a urea bond structure. The following five reactions will occur during its prepolymerization and moisture curing: [0003] [0004] Among them, reaction formulas I and II mainly occur in the prepolymerization stage, reaction formula V mainly occurs in the moisture curing stage, and reaction formulas III and IV may occur in both prepolymerization and moisture curing stages, wherein reaction formulas I, III and IV are in a certain There is a clear reversibility of the reaction under certain conditions. If the components of each of the above reactions contain more than two functio...

Claims

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Application Information

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IPC IPC(8): G01N5/04
Inventor 石俊杰陈精华张健臻陈建军黄恒超
Owner GUANGZHOU BAIYUN CHEM IND
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