Hayeemasae Nabil, Saiwari Sitisaiyidah, Soontaranon Siriwat, Masa Abdulhakim
Department of Rubber Technology and Polymer Science, Faculty of Science and Technology, Prince of Songkla University, Pattani Campus, Pattani 94000, Thailand.
Research Unit of Advanced Elastomeric Materials and Innovations for BCG Economy (AEMI), Faculty of Science and Technology, Prince of Songkla University, Pattani Campus, Pattani 94000, Thailand.
Polymers (Basel). 2022 Jul 2;14(13):2713. doi: 10.3390/polym14132713.
Natural rubber latex (NRL) is a polymer (blend) extracted from the milky sap of para rubber trees. Due to being a natural biopolymer, NRL contains various proteins that may be allergenic to humans when in skin contact. Attempts have been made to use deproteinized natural rubber (DPNR) instead of impure NRL, and the final properties of these two types of rubber tend to differ. Thus, the correlations between their chemistry and properties are of focal interest in this work. DPNR was prepared by incubating NRL with urea, followed by aqueous washing/centrifugation. The physical, mechanical, and dynamic properties of incubated NRL before and after washing/centrifugation were examined to distinguish its influences from those of incubation with urea. According to the findings, the proteins, phospholipids, and chain entanglements were responsible for natural polymer networks formed in the NR. Although the proteins were largely removed from the latex by incubation, the properties of high ammonia natural rubber (HANR) were still maintained in its DPNR form, showing that other network linkages dominated over those contributed by the proteins. In the incubated latex, the naturally occurring linkages were consistently reduced with the number of wash cycles.
天然橡胶乳胶（NRL）是从巴拉橡胶树的乳状汁液中提取的一种聚合物（混合物）。由于是天然生物聚合物，NRL含有多种蛋白质，当与皮肤接触时可能会引起人类过敏。人们已尝试使用脱蛋白天然橡胶（DPNR）来替代不纯的NRL，这两种橡胶的最终性能往往有所不同。因此，它们的化学性质与性能之间的相关性是本研究的重点。DPNR是通过将NRL与尿素一起孵育，然后进行水洗/离心制备而成。对水洗/离心前后孵育的NRL的物理、机械和动态性能进行了检测，以区分尿素孵育的影响和水洗/离心的影响。根据研究结果，蛋白质、磷脂和链缠结是天然橡胶中形成天然聚合物网络的原因。尽管通过孵育从乳胶中大量去除了蛋白质，但高氨天然橡胶（HANR）的性能仍以其DPNR形式得以保持，这表明其他网络键合比蛋白质贡献的键合起主导作用。在孵育的乳胶中，随着洗涤次数的增加，天然存在的键合不断减少。
