STRUCTURAL IRREGULARITIES IN POLYVINYL-ALCOHOL)

被引:27
作者
ADELMAN, RL
FERGUSON, RC
机构
[1] DUPONT CO,CENT RES DEPT,WILMINGTON,DE 19898
[2] DUPONT CO,PLAST DEPT,WILMINGTON,DE 19898
关键词
ALCOHOLS - CHEMICAL REACTIONS - POLYMERIZATION - POLYMERS - Physical Properties - SPECTROSCOPIC ANALYSIS;
D O I
10.1002/pol.1975.170130409
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
In the reported investigation, PVA derived from the product of polymerization of vinyl acetate in methanol have been characterized by various physical and chemical methods before and after NaIO//4 cleavage. The 220-MHz **1H-NMR spectra confirm the reliability of NaIO//4 titrimetry for estimating 1,2-glycol content and help explain the tendency for viscometry to grossly underestimate the 1,2-glycol content for low molecular weight polymers. The spectra and related chemical evidence indicate that the major endgroups are HOCH//2CH//2 - and CH//3CH(OH)CH(OH)CH//2 - . beta -Hydroxyethyl groups also occur as short chain branches, mainly attached to alpha carbon atoms in the normal head-to-tail polymer chain sequence. The concentrations of the branch and endgroups depend on polymerization conditions and help explain polymerization ″solvent″ effects on physical properties.
引用
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页码:891 / 911
页数:21
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