Photodegradation of natural rubber latex by singlet oxygen generated from methylene blue

IF 1.2 4区化学 Q4 POLYMER SCIENCE

Journal of Rubber Research Pub Date : 2024-04-24 DOI:10.1007/s42464-024-00249-3

Suhawati Ibrahim, Nadras Othman

引用次数: 0

Abstract

Methylene blue undergoes decomposition upon the exposure to ultraviolet (UV) light and oxygen to release reactive species such as singlet and triplet oxygen. These reactive species have adequate energy to oxidise and degrade organic materials including natural rubber (NR). In this work, NR latex was exposed to UV in the presence of methylene blue and hydrogen peroxide to produce low molecular weight NR latex. The Mn of NR was reduced from 544 × 10³ g/mol to about 6 × 10³ g/mol with low gel content. During the photodegradation, the NR chain was cleaved at both C = C and C-C bonds. The molecular structure of LNR was similar to that of the NR but with new functional groups of hydroxyl and carbonyl, resulting from oxidation and chain cleavage. The rubber particles were originally pear-shaped but changed to spherical after the degradation reaction, although their size remained largely similar.

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亚甲基蓝产生的单线态氧对天然胶乳的光降解作用

亚甲基蓝在紫外线（UV）和氧气的照射下会发生分解，释放出单线态氧和三线态氧等活性物质。这些活性物质具有足够的能量来氧化和降解包括天然橡胶（NR）在内的有机材料。在这项工作中，NR 胶乳在亚甲基蓝和过氧化氢存在下暴露于紫外线下，生成低分子量的 NR 胶乳。NR 的锰含量从 544 × 103 g/mol 降至约 6 × 103 g/mol，凝胶含量较低。在光降解过程中，NR 链在 C = C 键和 C-C 键处都发生了裂解。LNR 的分子结构与 NR 相似，但由于氧化和链裂解产生了新的羟基和羰基官能团。橡胶颗粒原本是梨形的，但在降解反应后变成了球形，尽管它们的大小仍然基本相似。

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来源期刊

Journal of Rubber Research 化学-高分子科学

自引率

15.40%

发文量

审稿时长

3 months

期刊介绍： The Journal of Rubber Research is devoted to both natural and synthetic rubbers, as well as to related disciplines. The scope of the journal encompasses all aspects of rubber from the core disciplines of biology, physics and chemistry, as well as economics. As a specialised field, rubber science includes within its niche a vast potential of innovative and value-added research areas yet to be explored. This peer reviewed publication focuses on the results of active experimental research and authoritative reviews on all aspects of rubber science. The Journal of Rubber Research welcomes research on: the upstream, including crop management, crop improvement and protection, and biotechnology; the midstream, including processing and effluent management; the downstream, including rubber engineering and product design, advanced rubber technology, latex science and technology, and chemistry and materials exploratory; economics, including the economics of rubber production, consumption, and market analysis. The Journal of Rubber Research serves to build a collective knowledge base while communicating information and validating the quality of research within the discipline, and bringing together work from experts in rubber science and related disciplines. Scientists in both academia and industry involved in researching and working with all aspects of rubber will find this journal to be both source of information and a gateway for their own publications.