论文部分内容阅读
Stockmayer以六氟丙酮水合物为溶剂,在25℃时测定了聚甲醛的分子量和特性粘数[η],由此计算出Flory特征比C_∞为10.5,与中等柔性聚苯乙烯的C_∞值接近。作者认为该值偏高,是由于聚甲醛与溶剂形成强的氢键所致。本文以间甲酚(100℃)和对氯苯酚(60℃)为溶剂,采用Salchard-Stockmayer-Fixman外推法求得C_∞为6.19,比聚乙烯的C_∞值还小些,并指出聚甲醛的无扰尺寸与温度的关系不大。还订定了聚甲醛在两种不同溶剂体系中的MHS方程为[η]=3.87×10~(-2)M_η~(0.705) (间甲酚,100℃) [η]=2.00×10~(-2)M_η~(0.79) (对氯苯酚,60℃)
Stockmayer hexafluoroacetone hydrate as a solvent measured at 25 ℃ polyoxymethylene molecular weight and intrinsic viscosity [η], calculated from the Flory characteristic ratio C_∞ of 10.5, and moderate flexible polystyrene C_∞ value Close to The authors consider this value to be high due to the strong hydrogen bonding formed between POM and the solvent. In this paper, C_∞ was 6.19 by the extrapolation method of Salchard-Stockmayer-Fixman using m-cresol (100 ℃) and p-chlorophenol (60 ℃) as solvent, The non-interfering size of formaldehyde has little to do with the temperature. The MHS equation of polyformaldehyde in two different solvent systems was also defined as [η] = 3.87 × 10 -2 M_η ~ 0.705 (m-cresol, 100 ° C) [η] = 2.00 × 10 ~ (-2) M_η ~ (0.79) (p-chlorophenol, 60 ℃)