Effects of vacuum infusion processing parameters on the impact behavior of carbon fiber reinforced cyclic butylene terephthalate composites

Abstract

Carbon fiber reinforced cyclic butylene terephthalate composites have been processed by vacuum infusion under two different non-isothermal processing routes starting from a one-component cyclic butylene terephthalate resin system. One of them was processed under a short cycle with fast cooling, and another one was processed under a long cycle with slow cooling. Both the micro-structure and low-energy impact properties of the composites have been investigated. On one hand, the fast cooling generates randomly dispersed voids and porosities in the resin-rich regions during the crystallization-induced shrinkage. On the other hand, the slow cooling generates a highly crystalline and brittle matrix without porosity. However, many micro-cracks appear in the resin-rich regions due to the combination of the brittleness and longitudinal shrinkage of the matrix. The critical delamination energy of the slow cooled composite is slightly higher than that of the fast cooled one, whereas this latter absorbs over 25% more energy before being penetrated, as well as performing in a less brittle way. The lower interlaminar shear strength of the fast cooled composite is suggested to be the origin of its higher energy absorbing capability and less brittle behavior.

Mechanical Properties of Layered-Carbon Fiber Reinforced with Vacuum Infusion Process

“…It increases when the core thickness is increase [16]. The molding time and the density of composites [17], [18]. The shortest time of molding process causes uneven thickness and different width of specimen.…”

Monomer Selection for In Situ Polymerization Infusion Manufacture of Natural-Fiber Reinforced Thermoplastic-Matrix Marine Composites

“…Many researchers have reported LCM production of thermoplastic polybutylene terephthalate (PBT) composite from cyclic butylene terephthalate (CBT) oligomers. Commercial CBT was usually used in these studies, with the polymerization temperature ranging from 190-260 • C [64,[109][110][111][112][113]. Commercial CBT is normally a mixture of oligomers between two and seven repeat units, i.e., from the dimer to the heptamer [111,114].…”

A Review of the Recent Advances in Cyclic Butylene Terephthalate Technology and its Composites

“…194 As already mentioned earlier, Yu and co-workers 76 Agirregomezkorta and associates [198][199][200][201][202] used vacuum infusion to produce woven CF fabric-reinforced pCBT composites and compared them to equally produced epoxy-based composites. The pCBT-based composite presented a higher shrinkage and void content than the epoxy-based one due to the volumetric shrinkage associated with pCBT crystallisation.…”