Preparation and Properties of Thermoplastic Polyamide-imide and Polyurea-amide-imide/Copper Foil Composites

Abstract

Polyamide-imide (PAI) and polyurea-amide-imide (PUAI) resins were polymerized from five reactants: 4,4'-oxydianiline, 4-nitrobenzoyl chloride, 4,4'-diphenylmethane diisocyanate, 1,2,4,5-benzenetetracarboxylic dianhydride, and 3,3'-4,4'-benzophenone tetracarboxylic dianhydride. Their chemical structures were characterized using elemental analysis, FTIR and 1H NMR spectroscopy. Their thermal properties, adhesive properties, electrical properties, heat resistance, and chemical resistance were studied. The experimental results show that the glass transition temperatures of PAI and PUAI films occurred respectively at 360 °C and 229 °C, and the 10% weight loss occurred respectively at approximately 481 °C and 420 °C. The optimal hot-press conditions for PAI/copper foil (CU) composite were 380°C and 4.90 MPa, whereas those for PUAI/copper foil (CU) composites were 250 °C and 4.90 MPa. Values of the peel strength, dielectric constant, and dissipation factor were obtained and the peel strength was re-measured after a thermal stability test. The chemical resistance tests showed that the peel strength retention values of the PAI/CU and PUAI/CU composites were respectively more than 95% and more than 94% after immersing in 10% H2SO4 solution at 70 °C for 1 h.