Powdered Rubber: Fabrication and Evaluation of Its Physical/Biological Property

Because of its difficulty in manipulation and short shelf-life, the colloidal form of natural latex presents pitfalls when used in the manufacture of small medical and dental elastic products. Objective: To fabricate natural latex into powder form and to evaluate the physical and biological properties of the powdered rubber. Methods: Natural latex was vulcanized and grafted with ethylmethacrylate by gamma irradiation. Grafted vulcanized latex was fabricated into powder form by agitation in a container and was dried at 80°C for 24 hrs. The powdered rubber was analyzed for its powder size and grafting efficiency, then cast in sheet form for evaluation of water absorption, tensile strength, tear strength, and cytotoxicity. Results: The average particle size diameter was 1.2 mm, and grafting efficiency was 90%. The grafted rubber showed lower water absorption and higher tensile strength and tear strength, compared with pure rubber, in the control group. No cytotoxic effect was observed in the in vitro study. Conclusion: Fabrication of natural rubber latex into powder form by this technique improved the physical and biological properties of natural rubber. Therefore, it would be worth introducing the powdered rubber, and its method of fabrication, into the field of polymers for medical and dental materials.