Crosslinking reaction of poly(vinyl alcohol) with poly(acrylic acid) (PAA) by heat treatment: Effect of neutralization of PAA
Crosslinking reaction of poly(vinyl alcohol) with poly(acrylic acid) (PAA) by heat treatment: Effect of neutralization of PAA
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DOI：
10.1002/app.12910
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发表时间：
2003-11-28
影响因子：
3
通讯作者：
Mizoguchi, K
中科院分区：
文献类型：
--
作者：
Kumeta, K;Nagashima, I;Mizoguchi, K
以聚丙烯酸(PAA)为交联剂，研究了聚乙烯醇(PVA)的酯化交联反应，得到了高不溶的PVA材料。制备了PVA和PAA(PVA/PAA=8/2)共混膜，考察了PAA的中和度和热处理条件对交联度的影响。PAA的动态链节数不同，其交联度也有很大差异。交联反应的最佳dN为5~10mol%。对于未中和的PAA，在200℃下热处理20min，其交联度最高可达15mol%。在相同的热处理条件下，加入部分中和的PAA(dN=10摩尔%)，可使增韧程度提高到40摩尔%左右。FTIR分析表明，薄膜中PVA的羟基与未中和的PVA发生了共混。由于热处理，PAA的降解程度大于部分中和的PAA。结果表明，低pH条件下的热处理促进了PVA羟基的降解，从而减少了酯化交联点的数量。(C)2003年威利期刊公司。
The crosslinking reaction of poly(vinyl alcohol) (PVA) by esterification using poly(acrylic acid) (PAA) as a crosslinking reagent was investigated to obtain highly insoluble PVA materials. Blend films of PVA and PAA (PVA/PAA = 8/2) were prepared to examine the effect of degree of neutralization (DN) in PAA and heat-treatment conditions on the degree of crosslinking reaction. The degree of crosslinking reaction varied significantly when the DN of PAA changed. The optimum DN for the crosslinking reaction was in the range of 5 to 10 mol %. In the case of unneutralized PAA, the degree of crosslinking reaction was at most 15 mol % by heat treatment for 20 min at 200degreesC. Applying partially neutralized PAA (DN = 10 mol %) raised the degree to about 40 mol % under the same heat-treatment conditions. FTIR analysis revealed that the hydroxyl group of PVA in the film blended with unneutralized. PAA was degraded to a greater degree than that with partially neutralized PAA as a result of heat treatment. It was found that heat treatment at a low pH condition enhances the degradation of the hydroxyl group of PVA, resulting in a decrease of the number of crosslinking sites by esterification. (C) 2003 Wiley Periodicals, Inc.