Effect of aliphatic chain in dicarboxylic acids on non-isothermal crystallization and mechanical behavior of titanium dioxide/iPP composites Article uri icon

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%27s and Mo%27s 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 %25 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%27s modulus were modified by functionalized TiO2 particles, being the acid with the longest chain (azelaic acid) the one that more increased this parameter. © 2020 Elsevier B.V.
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publication date

  • 2020-01-01