A Kinetic Analysis of the Thermo-Oxidative Degradation of PU/POSS nanohybrid Elastomers

作者：Janowski Bartlomiej^*; Pielichowski Krzysztof

来源：Silicon, 2016, 8(1): 65-74.

DOI：10.1007/s12633-014-9192-4

• Silsesquioxanes
• Polyurethanes
• Thermal stability
• Kinetic analysis
• Decomposition

A series of polyurethane/polyhedral oligomeric silsesquioxane (PU/POSS) nanohybrid elastomers, synthesized from diphenylmethane-4,4'-diisocyanate (MDI), polyoxytetramethylenediol (PTMG), 1,4-butanediol (BD) and 1-(1-(2,3-dihydroxypropoxy) butyl)-3,5,7,9,11,15-isobutyl-pentacyclo-[9.5.1.1(3,9).1(5,15).1(7,13)]-octasiloxane(PHIPOSS), have been submitted to thermal stability investigations under an oxidizing atmosphere. The polymers were prepared with differing amounts of silsesquioxane units in their hard segments (0, 4 and 10 wt. %). It was observed that POSS influenced the thermal stability of PU/POSS nanohybrid systems both in the first and second stage of the degradation process. Ozawa-Flynn-Wall and Friedman Kinetic analyses revealed that the activation energy (E-a) and pre-exponential factor (A) increased in the first stage and decreased in the second stage of the thermal degradation as a result of PHIPOSS introduction into PU elastomers. The best approximation of the f(alpha) function was found for a reaction of nth order with an autocatalysis/n-dimensional nucleation model in the case of neat PU and a reaction of nth order with an autocatalysis/reaction nth order model for the nanohybrid elastomers.

• 出版日期2016-1