【摘要】 用熔融共混法制备了聚己内酯(PCL)/纳米CaCO3复合材料,考察了纳米CaCO3对PCL结晶性能和纳米CaCO3含量对PCL/纳米CaCO3复合材料力学及形状记忆性能的影响。DSC结果显示纳米CaCO3对PCL的成核结晶有一定促进作用,辐照交联使PCL的结晶熔融温度和开始结晶温度分别提高3~5℃和2~5℃;DMA结果显示复合材料的模量随纳米CaCO3含量增加而增大,但高于40%后基本无变化。纳米CaCO3含量在5%~15%范围内能明显提高PCL的拉伸强度、弯曲强度和杨氏模量;辐照交联也起到增强各组分复合材料力学性能的作用,其变化的规律与交联前一致。复合材料经辐照交联后具有形状记忆特性,随着纳米CaCO3含量的增加,形变后的材料在熔融温度下开始回复所需时间缩短,回复速率加快,所有组成的样品在所测试的实验条件下最终回复率达97%以上。扫描电子显微镜观察表明纳米CaCO3粒子在PCL基质中无明显团聚现象。更多还原

【Abstract】 Poly（ε-caprolactone,PCL）/nano-CaCO₃ blends were prepared by mechanically melting mixing.The effects of nano-CaCO₃ particles on the crystallinity of PCL and the nano-CaCO₃ content on the mechanical properties as well as shape memory properties of the blends were investigated.DSC showed that nano-CaCO₃ particles promoted nucleation and crystallization of the PCL in the blends,the irradiation increased the melting temperature and crystallization temperature of PCL about 3 ℃ to 5 ℃ and 2 ℃ to 5 ℃ respectively.The modulus of the blends increased with increasing the content of nano-CaCO₃ from the DMA results until up to 40%.It was shown that there was an optimum nano-CaCO₃ mass fraction between 5% and 15% at which PCL/nano-CaCO₃ blends with higher mechanical strength and modulus could be obtained.The PCL/nano-CaCO₃ blends were also reinforced by irradiation in some extent compared with the blends unirradiated.It was confirmed that the shape memory effect could be retained in the developed blends after irradiation.The starting recovery time of the deformed blends at 60 ℃ decreased with increasing the CaCO₃ contents,while the rate of recovery increased.The total recovery ratio for all specimens reached 97% in the experimental conditions.The SEM showed that nano-CaCO₃ was dispersed homogeneously in the matrix of PCL.更多还原