This is the first report on studies carried out in detail on high-pressure oxygen copolymerization (>50 psi) of the vinyl monomers styrene and R-methylstyrene (AMS). The saturation pressure of oxygen for AMS oxidation, hitherto obscure, is found to be 300 psi. Whereas the ease of oxidation is more favorable for styrene, the rate and yield of polyperoxide formation are higher for AMS. This is explained on the basis of the reactivity of the corresponding alkyl and peroxy radicals. Below 50 °C, degradation of the poly(styrene peroxide) formed is about 2.5 times less than that observed above 50 °C, so much so that it gives a break in the rate curve, and thereafter the rate is lowered. Normal free radical kinetics is followed before the break point, after which the monomer and initiator exponents become unusually high. This is interpreted on the basis of chain transfer to the degradation products. The low molecular weight of polyperoxides has been attributed to the (i) low reactivity of RO2 • toward the monomer, (ii) chain transfer to degradation products, (iii) facile cleavage of O-O bond, followed by unzipping to nonradical products, and (iv) higher stability of the reinitiating radicals. At lower temperatures, (i) predominates, whereas at higher temperatures, chiefly (ii)-(iv) are the case.

In an effort to understand the role of molecular structure on the thermal properties of polyesters and copolyesters, the following polyesters were synthesized:  poly(1,4-cyclohexane dimethylene terephthalate) (PCT), poly(butylene-1,4-cyclohexane dicarboxylate) (PBCD), poly(1,3-cyclopentane dimethylene terephthalate) (PCPDT), and poly(butylene-1,3-cyclopentane dicarboxylate) (PBCP). PCT and PCPDT are semicrystalline polymers with crystallization and melting temperatures higher than poly(butylene terephthalate) (PBT). However, PBCD and PBCP have lower glass transition temperature than PBT. From these homopolymers a series of poly(butylene-co-1,4-cyclohexane dimethylene terephthalate) (P(BT-co-CT)), poly(butylene terephthalate-co-1,4-cyclohexane dicarboxylate) (P(BT-co-BCD)), poly(butylene-co-1,3-cyclopentylene dimethylene) (P(BT-co-CPDT)), and poly(butylene terephthalate-co-1,3-cyclopentane dicarboyxlate) (P(BT-co-PBCP)) random copolyesters were synthesized for the first time, and their cocrystallization behavior was investigated using differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The copolymers were found to be statistically random and crystallized in all compositions. The P(BT-co-CT) and (P(BT-co-CPDT) copolyesters exhibited typical eutectic behavior in melting and crystallization, which indicated isodimorphic cocrystallization behavior. On the other hand, in the case of P(BT-co-BCD) and P(BT-co-PBCP) copolymers, the melting and crystallization temperatures showed linear dependency with composition, indicating isomorphic-like crystallization behavior.

Poly(butylene terephthalate‐co‐cyclohexylene dimethylene terephthalate) copolymers PBTCT, were synthesized by melt condensation with compositions ranging from 94/08 to 23/77. 13C NMR spectroscopy was used to study the microstructure of the copolyesters and was found to be completely random. The melting temperature, crystallization temperature on cooling, enthalpy of melting and crystallization followed an eutectic behaviour. Thermal and x‐ray diffraction studies indicated that the copolyesters in all composition could crystallize. The XRD studies further indicated that PBT rich copolyesters in the range 75 to 100% BT, crystallized in the PBT lattice while the copolyesters rich in PCT having 38 to 100% CT, crystallized in the PCT lattice.

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N-(2-Aminobenzylidene)-4-methylanilines-Stable and Cheap Alternate for 2-Aminobenzaldehydes: Concise Synthesis of 3-Unsubstituted-2-aroylindoles. -(VIVEKANAND, T.; SANDHYA, T.; VINOTH, P.; NAGARAJAN, S.; MAHESWARI, C. U.; SRIDHARAN*, V.; Tetrahedron Lett. 56 (2015) 38, 5291-5294, http://dx.