【作者】 王迎进；

【导师】 高俊刚； 闰明涛；

【作者基本信息】 河北大学 ， 材料物理与化学， 2007， 硕士

【摘要】 聚对苯二甲酸丙二酯(Polytrimethylene terephthalate,简称PTT)是继聚对苯二甲酸乙二酯(PET)工业化和聚对苯二甲酸丁二酯(PBT)产业化以后,新实现工业规模开发的可成纤的聚酯材料。近年,国外已经开始进行大规模的PTT的生产和开发,PTT优异的回弹性和易染性引起纤维材料界的瞩目,国外已把它列为21世纪的新型纤维之一。另外,PTT在工程塑料领域的研究亦逐渐开展起来,在工程塑料领域是具有发展潜力的新型材料。国内对PTT的研究还处于起步阶段,且主要集中于纤维方面的研究和开发,在工程塑料领域开展很少。本文基于PTT的化学、物理特性,并结合聚合物共混改性原理,制备了PTT/PEN共混材料,并系统研究了它们的结构和性能。用示差扫描量热仪(DSC)和偏光显微镜(POM)研究了PTT和PEN共混材料的玻璃化温度转变、结晶熔融行为、等温结晶动力学和结晶形态。分别用Avrami方程和Hoffman-Lauritzen理论对等温结晶过程进行了处理。实验发现,共混样品在无定型区是完全相容的,所有的共混样品都表现出一个相对较宽的玻璃化转变温度。等温结晶过程中的Avrami指数n在3.0～3.2范围之内,晶体增长方式为三维增长。等温结晶之后的熔融出现三重熔融峰,分别对应着PTT的熔融(低温处)和PEN不完善和比较完善晶体的熔融(高温处)。用Arrhenius方程计算了共混样品的结晶活化能,实验发现当PTT含量为40％时的结晶活化能小于PTT含量为20％时的样品,说明PTT的加入促进了PEN的结晶。从Hoffman-Lauritzen方程计算得PTT含量为20％和40％时,共混样品的Kg分别为1.5×105and 1.8×105K2,并且计算出了晶体生长时的单位面积的侧表面和折叠链表面自由能。所得结果和Avrami分析结果是一致的。共混样品的结晶形态研究发现,随着PTT含量的增加,晶体尺寸逐渐变大,晶体也变得越来越完善。用热失重分析仪研究了惰性气氛下聚对苯二甲酸丙二酯(PTT)／聚对萘二甲酸乙二酯(PEN)共混物的非等温热分解行为及其动力学。研究发现,不同PTT／PEN共混物的热降解为一个主要的热分解过程,热分解反应为一级反应。随着共混物中PEN质量分数的增加,共混物的起始分解温度逐渐升高,共混物的热稳定性逐渐提高,而且共混物的热分解反应活化能也逐渐增加,这是由于PEN分子链中萘环的热分解温度比PTT中苯环高,因此分子链的热稳定性比PTT要高。共混物中萘环的化学组成含量越高,则热稳定性愈高。更多还原

【Abstract】 Poly(trimethylene terephthalate) (PTT) is a new industrialized aromatic polyester after PET and PBT, the research and impolder have been cosmically carried out on overseas. Its outstanding elastic recovery and dyeability attract people’s attention, furthermore, its application as engineering plastic also developed. Unlucky, there is so little research about PTT in domestic, especially in engineering plastic field. In the present study, we prepared different kinds of enforced PTT composites and system studied its structure and properties.The isothermal crystallization and crystal morphology of poly(trimethylene terephthalate)/poly(ethylene 2,6-naphthalate) (PTT/PEN) blends have been investigated by using differential scanning calorimeter (DSC) and polarized optical microscopy (POM). The commonly used Avrami equation was used to fit the primary stage of isothermal crystallization. The Avrami exponents n were evaluated to be in the rage of 3.0-3.2 for isothermal crystallization. The subsequent melting endotherms of the blends after isothermal crystallization showed multi-melting peaks. The crystallization activation energy of blends with 20% and 40% PTT component were calculated to be-100.3 and-64.6 J/g for the isothermal crystallization processes by the Arrhenius’formula. The Hoffman-Lauritzen theory was also employed to fit the process of isothermal crystallization, and the kinetic parameters Kg of the blends with 20% and 40% PTT component were determined to be 1.5×105 and 1.8×105 K2, respectively.The spherulites morphology of the six binary blends formed at 190℃showed different size and perfect Maltese crosses when the PTT or PEN component varied, suggesting that the more PTT content, the larger or more perfect crystallites formed in binary blends.The non-isothermal degradation processes of poly(trimethylene terephthalate) (PTT) and poly (ethylene 2,6-naphthalate) (PEN) blends were studied by using thermogravimetry (TG) analysis in nitrogen. The non-isothermal degradation of various PTT/PEN blends were found to be two-staged degradation processes and first order reaction. The PTT/PEN blends with more PEN component exhibited with higher decomposed temperature than those with less PEN contents due to the naphthalene nucleus has a higher thermal stability than that of phenyl nucleus. The apparent activation energy (△E) of blends is calculated by Ozawa method and the results suggest that the blend with more content of PEN has a higher value of△E.更多还原