Huashi Liu

Synthesis of polymeric emulsifier and its application in epoxy emulsion-type sizing agent for carbon fiber

A new kind of polymeric emulsifier was readily synthesized through one-pot three-stage processes. Fourier transform infrared spectroscope (FTIR) combined with conversion rate of epoxide groups tests was applied to characterize the chemical composition of the polymeric emulsifier. The emulsion sizing based on the self-made polymeric emulsifier was prepared through phase inversion emulsification method. The stability of the sizing agent was evaluated by centrifugal sedimentation and particle size investigations. The surface morphology of CF was observed by scanning electron microscope (SEM). The effects of the sizing agent on CF handleability were examined by abrasion resistance, hairiness amount and stiffness tests. The results indicated that after sizing, the CF obtained an appreciable enhancement in handleability. Finally, interlaminar shear strength (ILSS) of sized CF/epoxy resin composite increased by 55.39% compared with that of the desized one.

The Influence of Thermal Fatigue on the Properties of Glass Fiber/ Epoxy Composites

In this paper, glass fiber reinforced epoxy composites were prepared according to laminated plates design principles by using glass fiber/epoxy composite prepreg. The mechanical property of glass fiber/epoxy composite and water absorption have been investigated before and after thermal cycles. Thermal cycles were performed in the temperature range between −40°—80°. Through different thermal cycles (0, 60, 120, 180 cycles), it was found that the mechanical property of different ply of glass fiber/epoxy matrix composites was decreased and water absorption of composites were increased. Moreover, scanning electron microscopy (SEM) was used to characterize the fracture morphologies of glass fiber/epoxy composites before and after thermal cycles. SEM images showed that after 180 thermal cycles, the bonding effect of glass fiber and epoxy matrix interfacial layer became worse and pores increased, leading to the decrease in the mechanical properties and the increase in the water absorption.

Preparation of Epoxy Sizing Agent for Carbon Fiber by Phase Inversion Emulsification

The epoxy resin and epoxidized polybutadiene were used to prepare the emulsion type epoxy sizing agent for carbon fiber by phase inversion emulsification method. Effects of weight ratio of mixed emulsifiers and emulsifiers/resin (ωe/r), shear rate and dripping speed of water on properties of emulsion were investigated by centrifugal sedimentation analysis, particle size analysis and zeta potential measurement. Results showed that the optimal emulsion was obtained when weight ratio of polyoxyethylene nonylphenol phosphoric ammonium (NP-10A) and polyoxyethylene styrenated phenol ether (602) was 2:1, ωe/r was 12%, shear rate was 10000 r/min. Conductivity of emulsion by different ωe/r was also investigated to represent the variation of conductivity during emulsification process.