This study aims to create a novel method for fast mass-production of carbon fiber-reinforced thermoplastic (CFRTP) intermediate substrates by using in-Situ polymerizable thermoplastic epoxy resin, which is fed on reinforcing fibers in monomer mixture form in impregnation process and then allowed to rapidly polymerize into linearly-extended thermoplastic high polymer. Comparison between the monomer viscosity of this resin and the melt viscosity of polypropylene (PP) implied that thermoplastic epoxy resin can impregnate into fiber bundles approximately 103 times faster than PP. The investigation of resin applying method to carbon fiber fabrics revealed that linearly applying method was better than planarly applying method in terms of less voids. Finally, two types of polymerization catalysts were investigated to rapidly polymerize thermoplastic epoxy resin. As a result, as short as 2.5-minute polymerization using the phosphorous-type catalyst allowed the resin polymerize into high polymer enough to exhibit practical flexural strength of 900 MPa or more when used as the matrix of CFRTP in the volume fraction of about 50 %.
Mg(OH)2 particles are immobilized onto the surface of cotton fiber by simple physical heat pressing method with the aid of swelling in ionic liquid and shrinkage in water. The effect of eco-friendly surface pretreatment of cellulase, UV and plasma on Mg(OH)2 immobilization for thermal stability and flammability of cotton fabric is discussed. Improved swelling effect of cellulose after surface treatment is beneficial to contact of Mg(OH)2 particles with cotton fiber. Due to good adhesion of Mg(OH)2 particles to fiber surface after partial dissolution and resolidification of fragmented fibril, the flame retardancy of cotton fabric is significantly enhanced under plasma pretreatment with the afterflame time of 1.0 s and afterglow time of 2.0 s. It is found that cellulase treatment is a mild treating method while plasma pretreatment improves flame retardancy at a cost of damaging fiber in a reasonable range.