PET/PTT共混体系的相容特性及力学性能研究

通过熔融共混法制备了聚对苯二甲酸乙二醇酯(PET)与聚对苯二甲酸醇酯(PTT)的共混物，采用差示扫描量热仪、动态热机械分析仪、万能电子试验机等对共混体系的热性能、动态力学性能及拉伸性能进行了测试。测得PET/PTT共混体系只有1个玻璃化转变温度(Tg)和损耗峰，表明在非晶区完全相容，其中纯PET的Tg为84℃，纯PTT的Tg低于50℃; 而双重熔融峰及热结晶峰宽化现象的出现表明，共混体系在晶区是部分相容，各组分倾向于分别进行有序化排列、单独结晶，其中纯PET的熔点为256℃，纯PTT的熔点为229 ℃;共混体系的拉伸模量和拉伸强度随PTT含量的增加呈上升趋势;但当共混比例接近时体系的拉伸模量和拉伸强度有所下降，共混比为5/5时的拉伸模量和拉伸强度分别低达1098MPa和51MPa。

Compatibilization and Mechanical Properties of PET/PTT Blends

Poly(ethylene terephathalatc)(PET)was blended with poly(trimcthylcnc tcrcphthalatc)(PTT) via melt blending. The thermal，dynamically mechanical and tensile properties of PET/PTT blends were investigated by DSC, DMA,and tensile test. It shows that PET/PTT blends possess an excellent compatibility in amorphous phase. The To of neat PET and PTT is 84 and below 50℃，the melting points arc 256℃and 229℃，respectively. The chain segments of PET and PTT tend to crystallize separately in crystal phase corresponding to the appearances of two melting peaks and the width of the peak. Tensile modulus and tensile strength of blends increased with ascending PTT content. However, tensile modulus and tensile strength of blends decrease with the blend ratio approaching 0.5.The minimum tensile modulus and tensile strength of PET/P"IT blends arc 1098 MPa and 51 MPa, respectively.