Crystallization of Polycarbonate in Solvent/Nonsolvent System and Its Application to High-Density polyethylene Composite as a Filler

摘要

Crystallization of polycarbonate (PC) was attempted by a precipitated method in a ternary system of PC/sol-ventonsolvent. Chloroform was used as a solvent, and isoprppanol was used as a nonsolvent. Crystallization of PC was clearly observed as a powdery state when chloroform/isopropanol mixtures were prepared by 68/32 and 61/39 vol%. Crystallinity of PC was evaluated by differential scanning calorimeter and X-ray diffractometer. As the difference of solubility parameters between PC and binary solventonsolvent mixtures became smaller, the relative crystallinity of PC was increased. The highest degree of PC crystallization was obtained when chloroform/isopropanol was mixed by 61/39 vol%. Subsequently, crystallized PC was used as a filler to high-density polyethylene (HDPE) composite. HDPE composite incorporated by crystallized PC filler improved its mechanical and thermal properties. Flexural modulus was increased from 620 to 990 N/mm2, and flexural strength was increased from 720 to 1080 N/mm2. And heat deflection temperature measurement and flammability test supported the enhancement of thermal property when crystallized PC was added to HDPE composite up to 40 wt%.