Synthesis, Properties And Application Research Of Poly(Imide-ether) Rod-Coil Block Copolymer

The covalent linkage of hard rodlike chain and soft coillike chain can produce rod-coil block copolymer. The difference of structure, polarity and the chemical incompatibility between rod and coil blocks drives them to phase separate; and the covalent linkage of hard rodlike chain and soft coillike chain restricts the macroscopical phase separation. In this reseach, we synthesized the rod-coil block copolymer with imide oligomer as hard chain and polyether as soft chain, and then investigated its self-assembly properties and improvement of thermal endurance and thoughing of epoxy resin.A series of poly(imide-ether) block copolymer (b-CPI) and random copolymer (r-CPI) with hard-and-soft chain were prepared via polycondensation of polyether-amine (D2000), 4,4'-oxydianiline (ODA) , and 3, 3', 4, 4'- oxydiphthalic dianhydride (OPDA). The polymers were characterized by FT-IR, 1H-NMR spectra, and further confirmed by GPC and TGA. The results indicated that Td of soft chain increases with the increase of hard PI chain content. Atomic Force Microscope (AFM) and Transmission Electron Microscope (TEM) image indicated varies nanoscale micro-patterns, can be obtained through copolymer self-assembly phase separation on the surface of mica. The factors such as solvent, concentration, annealing temperature and time, length of hard chain affected the self-assembly pattern.Through polycondensation of polyether-amine (D2000), 4,4'- Diaminodiphenyl methane (DDM), and Bisphenol A dianhydride (BISA-DA), and also the control of hard chain polyimide (PI'), the other type of poly(imide-ether) block copolymer (b-CPI') was systhesized, and investigated as toughen agent for DGEBA/DDM epoxy resin. Dynamic Mechanic Analysis (DMA) indicated that b-CPI'can toughen the epoxy resin and improve its thermal endurance obviously: both Storage Modulus E'and Modulus Loss E"descended, but flexibility increased. The Tg increased more than 15℃with b-CPI as toughen agent. AFM indicated b-CPI'dispersed homogeneously in the cured resin as nanoscale granules, which could separate stress, toughen epoxy resin and improve its thermal endurance effectively.