From a practical perspective, it is important to maintain or increase the mechanical properties of functional ethylene copolymers to those of nonpolar polyethylene (PE). In this contribution, we report the enhanced mechanical properties of acrylate- and 5-vinyl-2-norbornene (VNB)-based ethylene terpolymers. Originally, phosphine-sulfonate Pd1 and Pd2 with methyl and phenyl installed para to the sulfonic group were synthesized and characterized. Subsequently, long-chain (but more challenging) polar monomers in which the polar groups combined linearly with double bonds (butyl acrylate (BA) and ethylene glycol monomethyl ether acrylate (EGMA)) were chosen to obtain more flexible chain structures. Crosslinkable and cyclic VNB were used, targeting at rapid crosslinking and enhanced material properties. Ethylene copolymerization and terpolymerization could be efficiently achieved using this strategy, and polymers exhibited improved surface and similar or enhanced mechanical properties compared with those of PE. High activity (2.9 × 10⁷ g (mol h)⁻¹) and high molecular weight (3.8 × 10⁵) were simultaneously observed in ethylene homopolymerization. E-BA(0.64) and E-EGMA(0.87) had a strain-at-break as high as 1016% and 974%, respectively, and stress-at-break up to 45 MPa compared with those of ethylene homopolymer. VNB-based terpolymers E-BA(0.68)–VNB(0.94) and E-EGMA(0.73)–VNB(1) displayed better tensile elongations (723% and 714%) than those of ENB- and DCPD-based terpolymers. Furthermore, though similar thermoplastic properties to PE (strain recovery (SR) = 10%) were observed, enhanced mechanical properties of teropolymers were obtained after sulfur vulcanization, with SR = 19–23% and Δσ (stress differences) = 3.3–10.3 MPa.

中文翻译：

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丙烯酸酯和 5-乙烯基-2-降冰片烯基乙烯三元共聚物的增强机械性能：使用远程调制的膦-磺酸盐钯络合物的合理设计和合成


从实用角度来看，保持或提高功能性乙烯共聚物的机械性能高于非极性聚乙烯 （PE） 的机械性能非常重要。在这篇文章中，我们报道了基于丙烯酸酯和 5-乙烯基-2-降冰片烯 （VNB） 的乙烯三元共聚物的增强机械性能。最初，合成了甲基和苯基对位的膦磺酸盐 Pd1 和 Pd2 并对其进行表征。随后，选择了极性基团与双键（丙烯酸丁酯 （BA） 和乙二醇单甲醚丙烯酸酯 （EGMA））线性结合的长链（但更具挑战性）极性单体，以获得更灵活的链结构。使用可交联和环状 VNB，针对快速交联和增强材料性能。使用这种策略可以有效地实现乙烯共聚和三聚反应，并且与 PE 相比，聚合物表现出更好的表面和相似或增强的机械性能。在乙烯均聚中同时观察到高活性 （2.9 × 10⁷ g （mol h）^-1） 和高分子量 （3.8 × 10⁵）。与乙烯均聚物相比，E-BA（0.64） 和 E-EGMA（0.87） 的断裂应变分别高达 1016% 和 974%，断裂应力高达 45 MPa。基于 VNB 的三元共聚物 E-BA（0.68）–VNB（0.94） 和 E-EGMA（0.73）–VNB（1） 显示出比基于 ENB 和 DCPD 的三元共聚物更好的拉伸伸长率（723% 和 714%）。 此外，尽管观察到与 PE 相似的热塑性性能（应变恢复 （SR） = 10%），但硫硫化后三聚物的机械性能得到了增强，SR = 19-23%，Δσ（应力差异）= 3.3-10.3 MPa。