文献类型： 外文期刊

作者： Wang, Yueqiong ¹ ; Liu, Hongchao ¹ ; Zheng, Tingting ³ ; Peng, Zheng ¹ ; Wang, Rui ¹ ; Yu, Heping ¹ ; Wang, Qifang ¹ ; Liao, Shuangquan ² ; Liao, Lusheng ¹ ;

作者机构： 1.Chinese Acad Trop Agr Sci, Key Lab Trop Crop Prod Proc, Minist Agr & Rural Affairs, Agr Prod Proc Res Inst, Zhanjiang 524001, Guangdong, Peoples R China

2.Hainan Univ, Sch Mat Sci & Engn, Key Lab Adv Mat Trop Isl Resources, Minist Educ, Haikou 570228, Hainan, Peoples R China

3.Qiongtai Normal Univ, Haikou 571100, Hainan, Peoples R China

4.Hainan Prov Key Lab Nat Rubber Proc, Zhanjiang 524001, Peoples R China

关键词： Vulcanization bond types; Strain-induced crystallization; Tensile properties

期刊名称：POLYMER TESTING （ 影响因子：5.1； 五年影响因子：4.6 ）

ISSN： 0142-9418

年卷期： 2023 年 129 卷

页码：

收录情况： SCI

摘要： The crosslinking network structure is a crucial factor influencing the properties of natural rubber. Therefore, investigating the impact of different vulcanization bond types on the strain-induced crystallization behavior and properties of natural rubber can provide a theoretical foundation for producing high-performance natural rubber. In this study, diverse curing systems were employed to produce vulcanized natural rubbers with varying crosslink types. The crosslinking network structures of the vulcanized rubbers were analyzed using the tube model theory. Additionally, the effects of vulcanization bonds on strain-induced crystallization behavior and tensile properties were examined through in-situ X-ray diffraction and a tensile testing machine. The results revealed that the vulcanizate with monosulfidic bonds, formed under the effective vulcanization (EV) system, primarily comprised chemical crosslinking networks, resulting in a high tensile modulus, low elongation at break, and low tensile strength. Conversely, the vulcanizate under the conventional vulcanization (CV) system exhibited a distinct entanglement network impact compared to the chemical crosslinking network, resulting in a smaller tensile modulus but the highest elongation at break and the largest tensile strength. These differences stemmed from the distinct roles of vulcanization bonds within the crosslinking network. Specifically, the relatively short monosulfidic bond quickly reached the critical degree of orientation for crystallization during stretching, leading to higher crystallinity under the same strain. However, its shorter length caused earlier fracture during stretching, resulting in network heterogeneity, reduced elongation at break, and lower tensile strength. On the other hand, the longer polysulfidic bond underwent fracture recombination during stretching, with slower orientation and delayed crystallization. Nonetheless, this recombination improved network uniformity and integrity due to stress dissipation from the initial fracture, enhancing crystallinity, elongation at break, and tensile strength. This study elucidated the influence of vulcanization crosslinking on the tensile properties of vulcanizates.