Journal Textile Coloration and Finishing Year / Vol., Issue, Month 2023 / V.35,no.4,Dec Title A Study on the Vulcanization System and Two-Step Foaming Properties for Natural Rubber Foam Authors Sunhee Lee, Ye-Eun Park, and Dikshita Chowdhury Institution/Affiliations Dong-A University Pages/Total page pp.246 ~ 255 / 10 Language Korean Abstract In this study, we investigated for natural rubber foam to replace petrochemical- based neoprene foam. Experiments were conducted on vulcanization system and 2-step foaming process of natural rubber. The vulcanization system were EV(Efficient Vulcanization Cure), Semi-EV(Semi-Efficient Vulcanization Cure) and CV(Conventional Vulcanization Cure). In the 2-step foaming process, first molding temperature was 14 0℃, times were 15, 20, 25, and 30minutes, and the second molding temperature was 160℃, the times 5, 10, 15, and 20minutes. The cure and viscosity characterization were evaluated by oscillating disc rheometer (ODR) and mooney viscosmeter. Various mechanical characteristics, including hardness, tensile strength, elongation at the point of rupture, and tear strength, were quantified. Subsequently, an assessment of alterations in these mechanical attributes was conducted post-immersion in a NaCl solution. In addition degree of volume change was measured after immersing the NR foam in NaCl solution and the low-temperature permanent compression set was evaluated at 4℃. And expansion ratio and shrinkage ratio of NR foam were evaluated for 28 days. As a result the EV vulcanization system showed the least change in physical properties before and after salt water immersion, and the lowest shrinkage ratio for 28 days. In addition it was confirmed that the 2-step foaming optimum condition differed depending on the appropriate vulcanization condition. Keywords natural rubber, 2-step foaming, vulcanization system, physical properties, shrinkage ratio Download   Reference http://koreascience.or.kr/journal/OSGGBT.page