【摘要】 将两种不同构型的聚L-乳酸(PLLA)与聚D-乳酸(PDLA)共混、熔融、挤出、压制成圆形薄片,利用高级旋转流变仪测试其流变性能。结果表明,聚乳酸共混熔体(PLLA-PDLA)属于典型的切力变稀非牛顿流体,其黏流活化能较大,表观黏度对温度变化敏感度高;随温度的升高共混熔体PLLA-PDLA的结构黏度指数减小,非牛顿指数增加。成核剂(TMP)的加入,使共混熔体PLLA-PDLA的非牛顿指数n减小、结构黏度指数Δη增大、可纺性下降,当m(TMP)/m(PLLAPDLA)=0.5%时共混熔体PLLA-PDLA的可纺性相对较好。更多还原

【Abstract】 Blends of poly(L-lactic acid)(PLLA)and poly(D-lactic acid)(PDLA)were melted and cut into slices in round shape.The rheological properties of the melt blends were investigated by means of advanced rheometric expansion system.Results showed that PLLA-PDLA melt blends were the typical kinds of pseudo plastic fluids and had high values of viscous flow activation energy with the apparent viscosity sensitive to the temperature.The apparent viscosity index of PLLA-PDLA melt blends decreased and the non-Newtonian index increased while the temperature increased.After different contents of nucleating agent TMP added into the melt blends,the non-Newtonian index decreased whereas the apparent viscosity index increased.The melt blends were suitable for spinning when m(TMP)/m(PLLA-PDLA) was 0.5%.更多还原