Carbon and Composites Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA.
Macromol Rapid Commun. 2019 Jul;40(13):e1900059. doi: 10.1002/marc.201900059. Epub 2019 Apr 25.
An ionomeric, leathery thermoplastic with high mechanical strength is prepared by a new thermal processing method from a soft, melt-processable rubber. Compositions made by incorporation of equal-mass lignin, a renewable oligomeric feedstock, in an acrylonitrile-butadiene rubber often yield weak rubbers with large lignin domains (1-2 µm). The addition of zinc chloride (ZnCl ) in such a composition based on sinapyl alcohol-rich lignin during a solvent-free synthesis induces a strong interfacial crosslinking between lignin and rubber phases. This compositional modification results in finely interspersed lignin domains (<100 nm) that essentially reinforce the rubbery matrix with a 10-22 °C rise in the glassy-to-rubbery transition temperature. The ion-modified polymer blends also show improved materials properties, like a 100% increase in ultimate tensile strength and an order of magnitude rise in Young's modulus. Coarse-grained molecular dynamics (MD) simulations verify the morphology and dynamics of the ionomeric material. The computed result also confirms that the ionomers have glassy characteristics.
一种离子型、皮革状热塑性塑料，具有很高的机械强度，通过一种新的热加工方法由软质、可熔融加工的橡胶制备而成。在丙烯腈-丁二烯橡胶中加入等质量的木质素（一种可再生的低聚物原料），所得到的组合物通常会产生弱橡胶，其中木质素域较大（1-2 µm）。在基于富含芥子醇的木质素的这种组合物中，在无溶剂合成过程中添加氯化锌（ZnCl ）会导致木质素和橡胶相之间产生强烈的界面交联。这种组成上的改性导致木质素域很好地分散（<100nm），实质上增强了橡胶基质，玻璃化转变温度到橡胶态转变升高了 10-22°C。离子改性的聚合物共混物还表现出改善的材料性能，如极限拉伸强度增加 100%，杨氏模量提高一个数量级。粗粒度分子动力学（MD）模拟验证了离子材料的形态和动力学。计算结果还证实了离聚物具有玻璃态特性。
