聚对苯二甲酸乙二酯/聚苯乙烯共混体系的形态结构

Study on the Morphological Structure of Polyethylene Terephthalate/polystyrene Blends

本文用偏光显微镜和扫描电子显微镜研究了PET/PS共混体系在全部组成范围内的形态结构.研究结果表明:PET/PS共混体系的共混物形态为明显的2相结构,相界面清晰;当PS的质量分数小于30%时,PS为分散相,当PS的质量分数大于60%时发生相逆转,PET为分散相;在ω(PET)/ω(PS)=80/20-50/50范围内共混物的热压膜内含有复合粒子形态.PET及共混物(95/5,90/10)熔体均符合幂律方程τ=kγn,为切力变稀体系,呈假塑性流动,幂律指数n=0.9. 共混物中PS相的分散程度随剪切速率的增加而逐渐变好.

Polyethylene terephthalate/Polystyrene (PET/PS) blends were fabricated by solution mixed and melting methods, morphological structure was characterized by scanning electron microscope and optical polarizing microscope. Results indicate that the PET/PS blends are incompatible in all composition ranges, the interphase between the two components is clear. When the mass fraction of PS is below 30 %, the PS is dispersion phase, and when it is more than 60 %, the PS is continuous phase. When the ratio of PET and PS is in the range of 80/20 to 50/50, the thermocompression films have 'A-in-B-in-A' complex particles structure. When the ratio of PET and PET/PS is 95/5 and 90/10, the blends melts are pseudoplastic fluid. The dispersion degree of the melting blends can be improved with the increase of the shear rate.