Naddeo Simone, Barbera Vincenzina, Galimberti Maurizio
Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Via Mancinelli 7, 20131 Milano, Italy.
Polymers (Basel). 2024 Oct 3;16(19):2802. doi: 10.3390/polym16192802.
Driving a car at extreme speeds, road holding, and sustainability do not go together well. Formula 1 racing is exciting but is not an example of sustainability. The aim of this work was to use materials, suitable for the treads of high-performance racing tyres, that can favour both high performance and sustainability. In particular, the objective was to achieve high dynamic rigidity at high temperatures (>100 °C) and a stable crosslinking network. A copolymer from an industrial waste such as sulphur and a comonomer from a circular biosourced material were used as the crosslinking agent of an elastomer composite based on poly(styrene-co-butadiene) from solution anionic polymerization and a carbon black with a high surface area. The biosourced circular material was 1,6-(2,5-dimethyl-1-pyrrol-1-yl)hexane (HMDP), the di-pyrrole derivative of hexamethylenediamine. Two poly(S-co-HMDP) copolymers, with different S/HMDP ratios (6 and 8.9, Copolymer 1 and Copolymer 2) were carefully characterized by means of H-, C-, 2DH-H-COSY and 2D H-C HSQC NMR. The comparison of the spectra highlighted the substitution with sulphur of the β-position of the pyrrole ring: mono-substitution largely prevailed in Copolymer 1 and also bi-substitution in Copolymer 2. The copolymers were used as additives in the vulcanization system. Compared with a reference composite, they allowed us to achieve more efficient vulcanization, a higher density of the crosslinking network, higher dynamic rigidity, better ultimate tensile properties, and better stability of the crosslinking network at high temperatures. Compared with a traditional oil-based crosslinking agent for elastomer composites with high rigidity and a stable structure at high temperatures, such as the perthiocarbamate 6-((dibenzylcarbamothioyl)disulfaneyl)hexyl 1,3-diphenylpropane-2-sulfinodithioate, the poly(S-co-HMDP) copolymers led to higher dynamic rigidity and better ultimate tensile properties. These improvements occurring simultaneously are definitely unusual. This work paves the way for the upcycling of circular materials in a large-scale application such as in tyres.
以极高速度驾驶汽车、抓地力和可持续性很难兼顾。一级方程式赛车令人兴奋，但并非可持续性的典范。这项工作的目的是使用适合高性能赛车轮胎胎面的材料，使其既能兼顾高性能又能实现可持续性。具体而言，目标是在高温（>100°C）下实现高动态刚度以及稳定的交联网络。一种由工业废料硫磺制成的共聚物和一种来自循环生物源材料的共聚单体被用作基于溶液阴离子聚合的聚（苯乙烯 - 共 - 丁二烯）弹性体复合材料以及高比表面积炭黑的交联剂。这种生物源循环材料是1,6 -（2,5 - 二甲基 - 1 - 吡咯 - 1 - 基）己烷（HMDP），即六亚甲基二胺的二吡咯衍生物。通过H -、C -、2D H - H - COSY和2D H - C HSQC NMR对两种具有不同S/HMDP比例（6和8.9，分别为共聚物1和共聚物2）的聚（S - 共 - HMDP）共聚物进行了详细表征。光谱比较突出了吡咯环β位的硫取代情况：单取代在共聚物1中占主导，双取代在共聚物2中也存在。这些共聚物被用作硫化体系中的添加剂。与参考复合材料相比，它们使我们能够实现更高效的硫化、更高密度的交联网络、更高的动态刚度、更好的极限拉伸性能以及在高温下更好的交联网络稳定性。与传统的用于在高温下具有高刚性和稳定结构的弹性体复合材料的油基交联剂（如过硫代氨基甲酸盐6 -（（二苄基氨基甲硫酰基）二硫烷基）己基1,3 - 二苯基丙烷 -2 - 亚磺酰二硫代酸酯）相比，聚（S - 共 - HMDP）共聚物具有更高的动态刚度和更好的极限拉伸性能。这些改进同时出现确实不同寻常。这项工作为循环材料在轮胎等大规模应用中的升级再利用铺平了道路。
