Crystallization derivation of amine functionalized T-12 polyhedral oligomeric silsesquioxane-conjugated poly(ethylene terephthalate)

Abstract

Most inorganic nucleating agents for poly(ethylene terephthalate) (PET) have limited nucleating ability due to poor compatibility with PET. Polyhedral oligomeric silsesquioxanes (FOSS) is a type of cage shaped organic/inorganic hybrid nanoparticles with three different particle sizes: octameric (T-8), decameric (T-10), and dodecameric (T-12). FOSS is considered as a promising nucleating agent for PET because the inorganic moieties contribute to high thermal stability and nucleation and the organic moieties can be tethered to PET chains. In contrast to T-8 FOSS, the nucleation ability of T-12 FOSS for PET has been poorly reported. In this study, our newly synthesized aminopropyl functionalized T-12 FOSS (A-FOSS) is proposed as a potential nucleating agent for PET. The amine group of A-FOSS is able to be chemically conjugated to PET chains, thereby giving a more homogeneous dispersion of T-12 POSS in PET than nonfunctional T-12 Phenyl POSS (N-POSS). Its PET composites gave a similar to 1.2 fold higher crystallization temperature and similar to 2.7 fold higher shear-induced crystallization rate over pristine PET. Such nucleating effects for PET is more effective than those of non-functional T-12 FOSS and the more widely studied T-8 POSS. This strategy is potentially beneficial for the high-shear melt processes of PET such as spinning and film extrusion. (C) 2017 Elsevier Ltd. All rights reserved.