Thermoplastic Elastomers Based on Functionalized Polystyrene with Crystallizable Diamide Segment: Synthesis and Characterization

ABSTRACT This article describes the synthesis and characterization of semicrystalline copolymer based on dihydroxy‐terminated polystyrene and a uniform crystallizable diamide (TΦT or T6T) hard segment. The concentration of the diamide in the copolymer varies from 3 to 15 wt% by changing the length of soft segments using dimethylterephthalate as a chain extender. The inherent viscosity of the polymer is very high ranging between 1.6 and 2.9 dL/g. Differential scanning calorimetry spectrum shows Tg for soft and Tm for hard segment as expected for crystalline copolymer. The products are semicrystalline materials with a crystallization window of 3–9°C. Depending on the amide concentration in the copolymer, the hard segments melting temperature ranged between 149 and 275°C. Fourier‐transform infrared spectroscopy (FT‐IR) results show that the degree of crystallinity of the hard segment in the copolymer is very high, that is up to 97%. Temperature‐dependent FT‐IR shows that crystallinity is highly reversible with respect to temperature. Wide angle X‐ray scattering data also confirm that the materials are semicrystalline in nature. The solvent resistivity of these materials is extremely high even at a low concentration of (3%) amide content. The entire polymer shows low water absorption, depending on the concentration of amide segments.