Abstract Non-isothermal crystallization kinetics of isotactic polypropylene (iPP) and its composites prepared with functionalized titanium dioxide (TiO2) were investigated by varying both heating rate and dosage of functionalized particles. Jeziorny’s and Mo’s methods were used to describe the non-isothermal crystallization process. The behavior of crystallization activation energy as a function of the crystallinity degree was evaluated by applying an isoconversional method. The modification of the TiO2 surface was done by testing three different carboxylic acids: glutaric, pimelic and azelaic acid and these particles were tested at different concentrations in iPP, 0.1, 0.5 and 1 % w/w; which had a high effect on the crystallization process of the polymer matrix. It was demonstrated the efficiency of the dry basis chemical reaction as a method to modify with dicarboxylic acids the surface of TiO2 particles. Such organic coatings chemically bonded to the surface of the TiO2 promoted a better incorporation of the iPP chains during crystallization and there is a clear effect of the length of dicarboxylic acids since the acids with more carbons, pimelic and azelaic, decreased the time to reach the crystalline state. Besides, the values of Young’s modulus were modified by functionalized TiO2 particles, being the acid with the longest chain (azelaic acid) the one that more increased this parameter.

中文翻译：

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二元羧酸中脂肪链对二氧化钛/iPP复合材料非等温结晶和力学行为的影响

摘要 通过改变加热速率和官能化粒子的用量，研究了等规聚丙烯（iPP）及其与官能化二氧化钛（TiO2）制备的复合材料的非等温结晶动力学。Jeziorny 和 Mo 的方法用于描述非等温结晶过程。通过应用等转化方法评价作为结晶度函数的结晶活化能的行为。TiO2 表面的改性是通过测试三种不同的羧酸：戊二酸、庚二酸和壬二酸来完成的，这些颗粒在 iPP 中的不同浓度下进行了测试，分别为 0.1、0.5 和 1% w/w；这对聚合物基体的结晶过程有很大影响。证明了干基化学反应作为一种用二羧酸改性二氧化钛颗粒表面的方法的效率。这种化学键合到 TiO2 表面的有机涂层促进了结晶过程中 iPP 链的更好结合，并且二元羧酸的长度有明显的影响，因为具有更多碳的酸、庚二酸和壬二酸减少了达到结晶状态。此外，杨氏模量的值通过功能化的 TiO2 颗粒进行了修改，具有最长链的酸（壬二酸）增加了该参数。这种化学键合到 TiO2 表面的有机涂层促进了结晶过程中 iPP 链的更好结合，并且二元羧酸的长度有明显的影响，因为具有更多碳的酸、庚二酸和壬二酸减少了达到结晶状态。此外，杨氏模量的值通过功能化的 TiO2 颗粒进行了修改，具有最长链的酸（壬二酸）增加了该参数。这种化学键合到 TiO2 表面的有机涂层促进了结晶过程中 iPP 链的更好结合，并且二元羧酸的长度有明显的影响，因为具有更多碳的酸、庚二酸和壬二酸减少了达到结晶状态。此外，杨氏模量的值通过功能化的 TiO2 颗粒进行了修改，具有最长链的酸（壬二酸）增加了该参数。