Influence of the rigid amorphous fraction and segregation during crystallization in PHB/DGEBA blends

SEBASTIÁN TOGNANA; WALTER SALGUEIRO

POLYMER JOURNAL

SOC POLYMER SCIENCE JAPAN

Año: 2015 vol. 47 p. 789 - 795

0032-3896

A SAXS study of the crystallization process in PHB and PHB/DGEBA (poly(3-hydroxybutyrate/ diglycidyl ether of bisphenol A) blends with PHB/DGEBA weight ratios of 100/0, 90/10, 70/30 and 50/50 crystallized at 60°C and 100°C was performed. The measurements were performed at different stabilized temperatures between 30°C and 140°C. The relaxation of the rigid amorphous fraction influences the crystallization process at crystallization temperatures higher than 70°C, and the same rigid amorphous fraction constrains the development of crystals at temperatures less than 70°C. Evidence for interlamellar segregation without influence from the crystallization temperature for DGEBA contents less than 30% and indications of interfibrillar or interspherulitic segregation for DGEBA contents greater than 30% were observed. The results are discussed based on the segregation of DGEBA affecting the re-crystallization process of PHB. At high temperatures, the co-existence of lamellae with different dimensions was observed. The results also indicate that DGEBA reduces the possibility of secondary crystallization in the blends.