Cure Characteristics and Rheological Properties of Organically Modified Lanthanum Oxide-Natural Rubber Composites

The present work emphasizes on the cure features and rheological behaviour of organically modified gadolinium oxide-Natural rubber vulcanizates. The main aim of incorporating gadolinium oxide is to impart X-ray shielding property to rubber composites. Earlier lead based materials were used for this purpose, but due to high toxicity of lead, lanthanum based materials can be an excellent alternative. Gadolinium oxide was organically modified with methacrylic acid and is used as filler in rubber vulcanizates at different loadings from 0-40 parts per hundred rubbers. Modification was done to increase the adhesion between an inorganic gadolinium oxide and natural rubber matrix. Characterization of modified gadolinium oxide using X-ray diffraction shows that the particle size got reduced to nano regime which highly influences the vulcanizates properties. The increase in torque minimum and torque maximum with filler loading is in covenant with mechanical property studies. The swellingindex and swelling co-efficient decreaseswhile cross link densityenhances with filler percentage which reveals that a better interaction in molecular level is occurring between the modified filler and natural rubber than the unmodified one. (paper)