Howard Allen Colvin

Anionic polymerization and polymer properties of 2-isopropenylnaphthalene and 2-vinylnaphthalene

Abstract 2-Isopropenylnaphthalene (2-IPN) and 2-vinylnaphthalene (2-VN) were polymerized in toluene with sec-butyllithium initiator. For 2-IPN, equilibrium monomer concentrations were determined, as well as the enthalpy, entropy and ‘absolute’ ceiling temperature, for its polymerization. Densities of both polymers were measured and their solubility parameters were calculated. They are, respectively, for 2-IPN, 1.105 g cm−3 and 9.2 cal 1 2 cm −3 2 , and for 2-VN, 1.108 g cm−3 and 9.4 cal 1 2 cm −3 2 .

Sulfur/Olefin Copolymers as Vulcanizing Agents for Rubber

Abstract Sulfur/olefin copolymers are known as vulcanizing agents for rubber, but synthetic procedures for these materials are poor and there is little in the literature to relate the structure of the copolymer with the vulcanizate properties of the rubber. This study discusses a new suspension process for the preparation of sulfur/dicyclopentadiene and sulfur/dicyclopentadiene/styrene copolymers. The relationship between the sulfur/olefin copolymer and vulcanizate properties is discussed in terms of the structure of the copolymer and other reaction products.

REACTIVELY CURABLE RUBBERS. I, DIENE ELASTOMERS WITH PENDANT ISOCYANATE AND/OR HYDROXYL FUNCTIONALITY

Abstract In conclusion, we have demonstrated that modified diene elastomers containing active hydrogens and/or blocked-isocyanate derivatives can be crosslinked (cured) by three distinct methods. These methods include: 1. reaction of polymer-bound active hydrogens with monomeric polyisocyanates (Type I), 2. reaction of polymer-bound isocyanates with compounds containing two or more active hydrogens (Type II), and 3. reaction between polymer segments that contain both polymer-bound isocyanates and active hydrogens (Type III). Additionally, we have shown that the new polymerizable blocked-isocyanate derivatives (Type II and III systems) can be readily incorporated into SBR and NBR elastomers by standard emulsion-polymerization techniques. The degree and distribution of these monomers within the elastomer matrix were shown to be controlled by knowledge of their reactivity ratios. Furthermore, we have shown that the processing and properties of these systems can be readily controlled by the proper combination...

Synthesis of copolymers of m-diisopropenylbenzene and m-dimethoxybenzene

The polymerization of diisopropenylbenzenes (DIPB’s) was first reported over 25 years ago. As opposed to free radical initiated polymerizations, which produce cross-linked gels ionic initiated polymerizations produce soluble (uncrosslinked) polymer. Anioic techniques, for examples, can produce linear polymer in which only on unsaturation of each DIPB is consumed. The aromatic ring of each pendant group thus carries an unreacted isopropenyl group.1