Synthesis and optical properties of a new series of side-chain poly(amic acid)s with p-π conjugation

After the condensation polymerization of benzoguanamine (BGA) and pyromellitic dianhydride (PMDA) under microwave irradiation, the resulting p-pi conjugate poly(amic acid) was grafted via the azo coupling reaction. The obtained side-chain polymers were further grafted with TDI-aliphatic alcohol derivatives and TDI-aniline derivatives. The third-order NLO coefficient and response time of PAA and graft polymers were measured by degenerated four wave mixing (DFWM) technique and their fluorescent properties were also investigated. All of the graft polymers have larger NLO coefficients and film-formability than PAA. Their fluorescent properties were also changed by the different electronic effect of the side-chains. The influences of the introduction of side-chains, the side-chain length and the electronic effect of the substituting groups on the azobenzol side-chain to both optical properties of the polymers by varying the conjugation degree were investigated.