Thermal Insulator Made from Solid Natural Rubber: Part 1 - Formulation of Rubber Compounding, Appropriate Forming Condition and Basic Properties

摘要

Closed cell rubber sponge applied as thermal insulator made from solid natural rubber (NR) was prepared by using Supercell DPT as a blowing agent. Rubber chemicals and STR 20, solid NR, were mixed on a two roll mill prior to prepare the specimen by hot press machine. Curing behaviors of the compounded solid NR with various types of sulfur and peroxide vulcanizations were characterized with moving die rheometer (MDR) at 150 and 170°C. Tensile and compressive strengths of the rubber insulator were measured by universal tensile testing machine followed by ASTM D412 and ASTM D395, respectively. Bubble size of the blown up rubber was inspected by an average maximum length of the bubble by using optical microscope. It should be notice from the experimental that all rubber formula both of sulfur and peroxide systems showed loading percentages to completely expand in a mold by about 38 to 48. Rubber insulator blown up with Supercell DPT used by semi-efficient vulcanization (semi-E.V.) unconcealed predominant results among all curing systems so that further investigations of the formulation as heat stuff will be discussed in next paper.