添加聚氨酯對於聚(3-羥基丁酸酯)/聚(L-乳酸)摻混系統相分離與結晶行為之影響

Abstract

The compatibility of poly(3-hydroxybutyrate) (PHB)/poly(L-lactide) (PLLA) blend in various compositions (100/0, 80/20, 50/50, 20/80, and 0/100), with and without compatibilizer, was investigated,. The compatibilizer was prepared from poly(3-hydroxybutyrate)-diol (PHB-diol) and poly(L-lactic acid)-diol (PLLA-diol) using 1,6-hexamethylene diisocyanate (HMDI) as a coupling reagent. With the evidence from GPC, IR and NMR results, we have confirmed that poly(PHB/PLLA urethane) (PEU) was successfully synthesized from PHB-diol and PLLA-diol. The thermal properties of PHB/PLLA with and without compatibilizer were observed by differential scanning calorimetry (DSC), and the crystallization behaviors and crystalline structures were analyzed by wild-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS). The miscibility was confirmed by an etching treatment and tensile test. When PEU was added in the blends, Tc of PHB and Tg of PLLA shifted to lower temperature. According to the results of WAXD, the crystalline lattice structure of PHB and PLLA, respectively, was not influenced by PEU. As indicated by the SAXS patterns, the lamellar thickness of the crystalline phase of PHB in the blends was become thick by PEU. The miscibility of the blends was slightly improved and the mechanical properties of the blends were increased by adding PEU. In a conclusion, PEU can improve the interfacial adhesion between PHB phase and PLLA phase in blends.