We prepared the geometric isomers of decahydro-2-naphthols as the source materials for the synthesis of poly(decahydro-2-naphthyl methacrylate)s [poly-(DNMA)-I, -II, -III, and -IV] including alicyclic ester groups with different geometric structures. The geometry and conformational dynamics of the decahydro-2-naphthyl moieties were investigated by NMR spectroscopy and DFT calculations. We synthesized each isomer of the methacrylic monomers, polymerized them, and investigated the optical, thermal, and mechanical properties of poly(DNMA)s with different isomer compositions. The T g values of the poly-(DNMA)s were in the following order: 139.3 °C for poly(DNMA)-II < 142.7 °C for poly(DNMA)-I < 146.2 °C for poly(DNMA)-III < 152.9 °C for poly(DNMA)-III/IV. On the basis of the dynamic motion of the alicyclic substituents determined by dynamic mechanical analysis, the tan δ peaks due to the β-relaxation for the a conformation change of the side group were observed for poly(DNMA)-I, while no peak was observed for poly(DNMA)-III. The activation energies for the β-relaxation were 65 kJ/mol for poly(DNMA)-I and 56−63 kJ/mol for the poly(DNMA)s including the four isomeric ester groups with various compositions. An increase in the DNMA-II content in the repeating units accelerated a dynamic conformation change, resulting in a decrease in the tan δ peak temperature and the activation energy value, as well as the glass transition temperature of the polymers. The optical property of the resulting polymers as the transparent polymer materials was also investigated. The density, refractive index value, and Abbe number of poly(DNMA)s were 1.04−1.10 cm 3 /g, 1.489, and 42−44, respectively.

Styrene-butadiene rubber (SBR) vulcanizates were prepared using plasticizers including the four liquid types of styrene-butadiene copolymers (LPSB), polybutadiene (LPB), polyisoprene (LPI), and the hydrogenated polyisoprene (LHPI) as well as the conventional process oil, and their phase-separated structures and mechanical properties were investigated by differential scanning calorimetry and dynamic mechanical spectroscopy. The phase separation was observed for the SBR vulcanizates when LPI and LHPI were used as the plasticizers, while the LPSB and LPB gave homogeneous structures because of the good miscibility with the SBR. The phase-separated structure of the SBR vulcanizate prepared using LPI changed to the homogeneous during the thermal aging. We revealed the role of the liquid polymers as the plasticizers in maintaining the physical and mechanical properties of the SBR vulcanizates during the thermal aging process when the plasticizers were miscible to the SBR. V C 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: [434][435][436][437][438][439][440] 2011

Styrene–butadiene rubber (SBR) vulcanizates were prepared using liquid polyisoprene (PI) and hydrogenated polyisoprene (HPI) as the plasticizers, and their structure and mechanical properties were investigated. The effect of the phase-separated structures of the SBR and the liquid polymers on the mechanical properties of the SBR vulcanizates was investigated. The constant physical properties were observed for the SBR vulcanizates during the thermal aging process when SBR and the plasticizer were miscible with each other in the vulcanizates.