Preparation and Properties of Modified Poly(amide-imide) with Oligo dimethylsiloxane = Preparation and Properties of Modified Poly(amide-imide) with Oligo dimethylsiloxane

다국어 초록 (Multilingual Abstract)

Poly(amide-imide)(PAI) is an important class of tractable polyimide. However, PAI is difficult to process by conventional means. The properties of PAI can easily be altered by incoporating siloxane blocks into PAI main chain. Therefore, many researchers have focused on the synthesis of siloxane PAI copolymer(SPAI).
Table 1 shows the recipe of the polymerization. Trimellitic anhydride acid chloride dissolved in THF dropped slowly into the mixture of phenylene diamine(PDA) and silicone diamine(SDA) mixture in THF under nitrogen atmosphere with vigorous stirring. The reaction was carried out for 1 day under N₂ atmostphere. The resulting polymeric solution was precipitated with acetone and the product was filltered. The product was dissolved in NMP and reprecipitated in distilled water for further purification. The silicone modified polyamide acid was dried in an oven for an imidization at 100, 150, 200 and 250°C.
SPAIs were easily dissolved in NMP, DMAc and DMF. Methanol and toluene was non-solvents. SPAI film was prepared from casting SPAI solution onto glass plate and drying in an oven.
The analysis of the structure of SPAIs was conducted by using FT-IR. The characteristic peaks of imide appeared 1778 and 1720cm^-1. The stretching vibrations of amide showed at ca, 1720, 1650 and 1545cm^-1. The characteristic peaks of Si-CH₃ appeared at 1260 and 860cm^-1 and that of Si-O show at 1090cm^-1. In our study, the thermal properties, X-ray diffraction and mechanical properties of SPAIs were also disscussed.