摘要
目前,受共价交联点对橡胶分子链运动的限制,采用硫磺、过氧化物等硫化剂制备的橡胶存在断裂伸长率低的问题,难以应用于高度拉伸或高韧性需求的场合。文中通过一步法在橡胶中引入键能居于共价键和氢键之间的脂肪族二硫键作为交联剂,制备了二硫键交联的环氧化天然橡胶体系,研究了二硫键含量与环氧化天然橡胶物理力学性能之间的关系。研究表明,随二硫键交联剂含量增加,橡胶交联密度和弹性模量增大,溶胀比降低。同时,随二硫键交联点含量增加,抗蠕变能力增强,应力松弛变慢。加入1.8 phr小分子交联剂,橡胶拉伸强度达4.88 MPa,断裂伸长率达1065%。加入2.8 phr小分子交联剂,橡胶拉伸强度达5.29 MPa,断裂伸长率达842%。经过3次重复加工后,橡胶的拉伸强度均可达到3 MPa左右,断裂伸长率接近300%。
At present,rubbers crosslinked with vulcanizing agents such as sulfur or peroxides generally exhibit low elongation at break due to the restriction effect of the covalent cross-linking points on the movement of rubber molecular chains,which makes them difficult to be applied at large strain conditions.In this paper,exchangeable aliphatic disulfide bonds,the bond energy of which is between covalent bonds and hydrogen bonds,were introduced into rubbers as vulcanizing agent by one-step method.The relationship between the content of disulfide bonds and the mechanical properties of epoxidized natural rubber was studied.The study reveals that increasing disulfide content substantially increases the crosslinking density and elastic modulus of rubbers while suppressing their swelling ratio.Enhanced disulfide crosslinking networks demonstrates significantly improvements in creep resistance and delayed stress relaxation dynamics.With 1.8 phr crosslinker dosage,the rubber exhibits a tensile strength of 4.88 MPa with exceptional elongation at break(1065%).Increasing the crosslinker dosage to 2.8 phr further boosts the tensile strength to 5.29 MPa while maintaining substantial ductility(842%elongation at break).Remarkably,after three reprocessing cycles,the rubbers retain the tensile strength around 3 MPa and the elongation at break close to 300%.These findings demonstrate the potential of disulfide-crosslinked rubber systems in balancing mechanical performance and sustainable reprocessing capabilities.
作者
刘杰
翟荣洋
孙鹏
郭小仟
雷巍巍
施德安
Jie Liu;Rongyang Zhai;Peng Sun;Xiaoqian Guo;Weiwei Lei;De’an Shi(School of Materials Science and Engineering,Key Laboratory of Green Preparation and Application of Functional Materials,Hubei Key Laboratory of Polymer Materials,Hubei University,Wuhan 430062,China)
出处
《高分子材料科学与工程》
北大核心
2025年第5期47-57,共11页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(52003077)
广东省高性能与功能高分子材料重点实验室开放基金(20240002)。
关键词
环氧化天然橡胶
脂肪族二硫键
一步法
高拉伸性
epoxidized natural rubber
aliphatic disulfide bonds
one-step method
excellent stretchability
