Highly Solvent-Resistant Polystyrene Based on Uniform Tetraamide Units

ABSTRACT In this article, segmented multiblock copolymers are synthesized using monodispersed tetraamide (T6T6T or T6A6T dimethyl) as hard segments and hydroxy‐terminated polystyrene (PSt) with a low molecular weight of 2500 g/mol as a soft segment. The soft segment length was varied from 2500 to 11,000 g/mol using dimethylterephthalate as a chain extender. The copolymers are characterized by inherent viscosity measurements, Fourier‐transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), water absorption, and solvent resistivity. The inherent viscosity increases with increasing soft segment length. Depending on the amide concentration in the copolymers, the hard segment melting temperature ranged between 248 and 287°C. From the FTIR, DSC, and wide angle X‐ray diffraction results, it is concluded that the hard segments in the copolymer are crystallized completely. All the polymers showed single‐stage decomposition temperature centered around 430°C. The solvent resistivity of these materials is extremely very high even at a low concentration of amide content (7%).