Authors: Kazuki Sugimura Shougo Katano Yoshikuni Teramoto Yoshiyuki Nishio
Publish Date: 2013/02/01
Volume: 20, Issue: 1, Pages: 239-252
Abstract
Blend miscibility of cellulose propionate CP with synthetic copolymers comprising Nvinyl pyrrolidone VP and vinyl acetate VAc units was examined and a data map was constructed as a function of the degree of substitution DS of CP and the VP fraction in the copolymer component Results of differential scanning calorimetry and Fourier transform infrared measurements indicated that the pairing of CP/PVPcoVAc formed a miscible or immiscible blend system according to the balance in effectiveness of the following factors 1 hydrogen bonding between residual hydroxyls of CP and VP carbonyls of PVPcoVAc 2 steric hindrance of propionyl sidegroups to the interaction specified in 1 3 intramolecular repulsion between the two units constituting the vinyl copolymer and additionally 4 structural affinity between two segmental moieties involving the propionyl group and VAc unit respectively The factor 3 inducing intercomponent attraction is responsible for the appearance of a socalled “miscibility window” in the miscibility map and the factor 4 substantially expands the miscible region whole wider relative to those in the maps for the corresponding blend series based on cellulose acetate and butyrate In further refined estimation by dynamic mechanical analysis and T 1ρ H quantification in solidstate 13C NMR it was found that the miscible blends of hydrogenbonding type using CPs of DS 27 were completely homogeneous on a scale within a few nanometers whereas the polymer pairs situated in the window region using CPs of DS 27 formed blends exhibiting a somewhat larger size of heterogeneity ca 5–20 nm
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