论文标题
恒星拓扑增加了薄聚合物膜中的弹道抗性
Star topology increases ballistic resistance in thin polymer films
论文作者
论文摘要
对于众多应用，具有更大影响和弹道抗性的聚合膜是高度期望的，但是最能满足该需求的分子构型仍可能会争论。我们使用粗粒分子动力学模拟研究了薄聚合物膜对弹道影响的抗性，研究线性聚合物链和恒星聚合物的融化，数字2 <= f <= 16和聚合度10 <= m <= m <= 50臂。我们表明，增加了臂f或臂M的长度，这两者都会在所研究的参数范围内产生更大的特异性穿透能量。在具有较大F的恒星中链的链条更大，可以通过内部重新排列恒星，而不是链条滑动，主要通过恒星的重排来消散能量。在膜变形过程中，具有较大F的恒星在与弹丸接触后不久显示出较高的能量吸收率，而具有较大M的恒星主要来自链条滑动，响应较大，这会导致较大的后部面部变形。我们的结果表明，恒星可能是对超薄薄膜的调整能量耗散机制有利的。这些发现为基于拓扑的策略奠定了基于抗影响的聚合物膜的策略。
Polymeric films with greater impact and ballistic resistance are highly desired for numerous applications, but molecular configurations that best address this need remain subject to debate. We study the resistance to ballistic impact of thin polymer films using coarse-grained molecular dynamics simulations, investigating melts of linear polymer chains and star polymers with varying number 2<=f<=16 and degree of polymerization 10<=M<=50 of the arms. We show that increasing the number of arms f or the length of the arms M both result in greater specific penetration energy within the parameter ranges studied. Greater interpenetration of chains in stars with larger f allows energy to be dissipated predominantly through rearrangement of the stars internally, rather than chain sliding. During film deformation, stars with large f show higher energy absorption rates soon after contact with the projectile, whereas stars with larger M have a delayed response where dissipation arises primarily from chain sliding, which results in significant back face deformation. Our results suggest that stars may be advantageous for tuning energy dissipation mechanisms of ultra-thin films. These findings set the stage for a topology-based strategy for the design of impact-resistant polymer films.
