Li Xiaofan, Zhang Xiaohu, Ji Huan, Wei Yanxing, Xie Xinzheng, Zhu Wenbin, Bi Jifu
Huangpu Institute of Materials, Centers for Aircraft Science, Guangzhou 510700, China.
Changchun Institute of Applied Chemistry Chinese Academy of Sciences, Changchun 130102, China.
Polymers (Basel). 2024 Jan 26;16(3):342. doi: 10.3390/polym16030342.
This study investigates the influence of poly(butadiene-isoprene) copolymer rubber (BIR) and TDAE oil on the crystallization and melting behavior of neodymium-based butadiene rubber (Nd-BR). The study demonstrates that the melting points of Nd-BR and its blends decrease with lower crystallization temperatures. Below the critical crystallization temperature (), the melting behavior shows dual peaks in distinct temperature ranges, which are attributed to different spherulitic sizes. The addition of BIR or TDAE oil lowers the , with TDAE oil exerting a more substantial effect. These diluents mainly influence the nucleation temperature and crystallinity level of Nd-BR while having a minimal effect on the crystallization mechanism. A master curve, which overlaps for various samples, is developed by correlating the peak melting temperature () with the . This curve facilitates a quantitative assessment of the effects of BIR and TDAE oil on Nd-BR, highlighting the greater influence of TDAE oil on the crystalline structure compared with BIR at equivalent mass fractions. By applying the Lorentz equation and multi-peak fitting, a relationship between the melting points and crystallization temperatures is established, enabling the calculation of the equilibrium melting points () for different samples. The findings show a reduction in the due to the diluents; specifically, the is approximately 0 °C for pure Nd-BR, and it decreases to -4.579 °C and -6.579 °C for samples with 50 PHR TDAE oil and 60 wt.% BIR, respectively.
本研究考察了聚（丁二烯-异戊二烯）共聚物橡胶（BIR）和环烷油对钕系顺丁橡胶（Nd-BR）结晶和熔融行为的影响。研究表明，Nd-BR及其共混物的熔点随结晶温度降低而降低。在临界结晶温度以下，熔融行为在不同温度范围内出现双峰，这归因于球晶尺寸不同。添加BIR或环烷油会降低临界结晶温度，其中环烷油的影响更为显著。这些稀释剂主要影响Nd-BR的成核温度和结晶度水平，而对结晶机理的影响最小。通过将峰值熔融温度与临界结晶温度相关联，绘制了一条适用于各种样品的主曲线。该曲线有助于定量评估BIR和环烷油对Nd-BR的影响，突出了在等量质量分数下，环烷油对晶体结构的影响比BIR更大。通过应用洛伦兹方程和多峰拟合，建立了熔点与结晶温度之间的关系，从而能够计算不同样品的平衡熔点。结果表明，稀释剂会使平衡熔点降低；具体而言，纯Nd-BR的平衡熔点约为0℃，对于含有50份/百份橡胶环烷油和60 wt.% BIR的样品，平衡熔点分别降至-4.579℃和-6.579℃。
