近日，美国麻省理工学院Johnson, Jeremiah A.团队报道了机械基团交联增强了聚合物的弹道能量耗散。相关论文于2026年6月3日发表在《自然》杂志上。

机械失效是塑料在结构件、防护涂层等应用中面临的显著局限。特别是高速变形下的穿孔破坏，很难通过传统的分子设计加以缓解。交联被广泛用于提高聚合物的热稳定性和化学稳定性，但在机械变形下，交联通常会使材料变得更脆，从而限制其抗冲击性能和使用寿命。因此，如何解决稳定性与韧性之间的这一根本性矛盾，仍是一项核心挑战。

研究组表明，将一小部分力敏机械载体作为交联点嵌入普通聚合物中，可以从根本上扭转这一矛盾，制备出的材料具有显著增强的弹道能量耗散能力。在应变率超过 10⁷ s^-1的条件下，机械载体交联网络吸收的能量比传统热固性材料高出约115%，甚至超过了其未交联的热塑性对应物。研究组将这一行为归因于力与绝热加热驱动的局域“热固性—热塑性”转变：选择性断裂的机械载体促进了冲击部位的粘塑性变形，同时保持周围区域的网络完整性。

研究组在玻璃态的聚苯乙烯和橡胶态的苯乙烯-丁二烯-苯乙烯三嵌段共聚物中验证了该策略的普适性。这些结果表明，机械载体交联可作为将大宗聚合物转化为抗冲击材料的设计原则，并为聚合物力化学与极端应变率材料行为的交叉研究开辟了新方向。

附：英文原文

Title: Mechanophore cross-linking enhances ballistic energy dissipation of polymers

Author: Sang, Zhen, Nguyen, Suong T., Ko, Kwangwook, Lin, Senpeng, Jang, Heecheol, Gonzalez-Zapata, Simon, Fitz, Sullivan, Kai, Yun, Kooi, Steven, Deng, Chuting, Olvera de la Cruz, Monica, Koslowski, Marisol, Kulik, Heather J., Craig, Stephen L., Nelson, Keith A., Johnson, Jeremiah A.

Issue&Volume: 2026-06-03

Abstract: Mechanical failure is a marked limitation for plastics used in structural, protective and coating applications. In particular, perforation under high-rate deformation is difficult to mitigate through conventional molecular design1,2. Cross-linking is widely used to improve the thermal and chemical stability of polymers, yet under mechanical deformation, it typically renders materials more brittle, limiting impact resistance and functional lifetime3. Overcoming this fundamental trade-off between stability and toughness remains a central challenge. Here we demonstrate that embedding a small fraction of force-sensitive mechanophores as cross-links into common polymers fundamentally reverses this trade-off, producing materials with substantially enhanced ballistic energy dissipation. At strain rates exceeding 107s1, we show that mechanophore-cross-linked networks absorb up to about 115% more energy than conventional thermosets and surpass even their uncross-linked thermoplastic counterparts. We attribute this behaviour to a force- and adiabatic-heating-driven local thermoset-to-thermoplastic transition, in which selective mechanophore scission facilitates viscoplastic deformation at the impact site while preserving network integrity in the surrounding regions. We demonstrate the generality of this strategy in both glassy polystyrene and rubbery styrene–butadiene–styrene triblock copolymers. These results establish mechanophore cross-linking as a design principle for converting commodity polymers into impact-resilient materials and open directions at the intersection of polymer mechanochemistry and extreme-strain-rate material behaviour.

DOI: 10.1038/s41586-026-10557-w

Source: https://www.nature.com/articles/s41586-026-10557-w