Abstract. Two novel azobenzene-functionalized polythiophenes, poly [4-((4-(phenyl)azo)phenoxy)butyl-3-thienylacetate] (P4) and the copolymer of 3-hexylthiophene and 4-((4-(phenyl)azo)phenoxy)butyl-3-thienylacetate (COP64) have been synthesized. The structure dependence of photoluminescence features and thermochromic behaviors of both azobenzenefunctionalized polymers was investigated. The results show that polymer structure has a strong influence on the conformation and optical properties of the resulting polythiophene derivatives. The photochemical control of photoluminescence property was achieved with homopolymer P4 using photoactive azobenzene side chains.

Polybutadiene-based polyurethane/poly (methyl methacrylateco-glycol dimethacrylate) interpenetrating polymer networks (PU (HTPB)/P(MMA-co-EGDMA)-IPN) was synthesized by simultaneous polymerization. FTIR and dynamic mechanical spectra (DMS) show no apparent chemical bonds between the two component polymers. The results of DMS also demonstrated that the interpenetration of networks exists mainly between P(MMA-co-EGDMA) and the hard segments of PU(HTPB). The results of transmitting electron microscopy (TEM) indicate that when the amounts of P(MMA-co-EGD-MA) are from 20 to 80 wt%, the domain sizes increase from 100 to 200 Å to several microns, and the morphology features vary from the interpenetration of microphase separation structure to the boundary interpenetration of cellular structure. Besides, the IPN has dual phase continuity. With increasing amounts of P(MMA-co-EGDMA), the stress-strain curves indicate that the corresponding IPN materials transform from reinforced rubbers to toughened plastics. The mechanical properties of the full-IPN are far superior to those of the corresponding linear blends, and also higher than those of the corresponding semi-IPN.