Mohammad Hosein Nasirtabrizi - Department of Applied Chemistry, Islamic Azad University, Ardabil Branch, Ardabil, Iran.
Hamideh Khosroshahi - Department of Applied Chemistry, Islamic Azad University, Ardabil Branch, Ardabil, Iran.

Synthesis of some novel indole derivatives has been undertaken by the reaction of poly(maleic anhydride-co-styrene), P(MA-co-St), poly(maleic anhydride-co-chloromethyl styrene), P(MA-co-CMS), poly(maleic anhydride-co-methyl methacrylate), P(MA-co-MMAc) and poly(maleic anhydride-co-methacrylate) P(MA–co–MAc), copolymers with indole in the presence of NaH at -5ºC. Compositions of the copolymers were obtained using related 1H NMR spectra and the polydispersity indices of the copolymers determined using gel permeation chromatography (GPC). The anhydride group possesses a higher reactivity with the indole group. The ring opening reaction between the anhydride group and the indole is simple and fast. All the resulted polymers were characterized by FT-IR and 1H NMR spectroscopic techniques. The glass transition temperature (Tg) of all the copolymers was determined by dynamic mechanical thermal analysis (DMTA). All the polymers containing indole groups showed a high glass transition temperature in comparison with the unmodified copolymers (I-IV). It was found that these polymers with indole moieties have high thermal stability and the presence of bulky indole groups in polymer side chains leads to an increase in the rigidity of polymers.

Chemical modification, Maleic anhydride, Indole, dynamic mechanical thermal analysis (DMTA), glass transition temperature