Structure-property relationships in copolyester fibers and composite fibers

Poly(ethylene terephthalate) is one of the most important engineering thermal plastics used for fibers, films and bottles. Despite its wide applications and vast global market, PET has shortcomings, which limits its usage in many areas. PET has a glass transition temperature (Tg) of 80°C, this temperature is too low for certain applications. Increase in glass transition temperature, high temperature mechanical properties, and dimensional stability is of great importance to further expand the applications of PET. Significant research efforts have been made toward this goal, using a variety of approaches. In this work, we attempt to improve the properties of PET melt spun filament. Three strategies have been investigated; (i) copolymerization of more rigid linear comonomer, 4,4'-bibenzoate unit into PET, (ii) UV crosslinking of functionalized PET fiber, and (iii) Reinforcement of PET with carbon nanofibers.