Effect of Heterogeneous Resin Curing Agent on Micro-mechanical Uniformity of Resin Matrix of Composites

Abstract

Preparation of prepregs by hot melt method is generally involved the infiltration of resin. For the epoxy resin with a heterogeneous curing system, the preparation of large thickness prepregs may be affected by the uneven distribution of curing agent. A nanomechanical method was used to study the micro-mechanical uniformity of the resin matrix of the composites prepared by thin thickness glass fibre prepregs and the glass fibre reinforced composites prepared by resin vacuum suction technology. The results show that to the composites prepared by thin thickness prepregs, the resin exhibits good micro-mechanical uniformity, the nano-hardness and wear properties of the resin at the different regions of the composite cross-section have a good uniformity. The composites prepared by resin vacuum suction method exhibits obvious layered distribution, the particles of the curing agent and accelerator are enriched at the outer surface of the fiber layer. The resin at the outer layer of the fibre layer has higher nano hardness and wear resistance, while to the resin about 0.4mm inside the fiber layer, its hardness goes down, a very low nano hardness of the resin deeply inside the fiber layer is observed.

Keywords

• latent curing agent
• epoxy resin
• composites
• nano-indentation
• micro-mechanical uniformity