High Modulus, Strength, and Toughness Polyurethane Elastomer Based on Unmodified Lignin
High Modulus, Strength, and Toughness Polyurethane Elastomer Based on Unmodified Lignin
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DOI：
10.1021/acssuschemeng.7b01481
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发表时间：
2017-09-01
影响因子：
8.4
通讯作者：
He, Chaobin
中科院分区：
文献类型：
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作者：
Li, Hui;Sun, Jiao-Tong;He, Chaobin
以未官能化的木质素为硬段，端聚丙二醇甲苯二异氰酸酯（PPGTDI）为软段，采用直接交联法制备了高刚度、高强度、高韧性的木质素基聚氨酯弹性体（LPUe）。研究了木质素分子量（3600和600 g mol（-1））和质量分数（5-40 wt %）对LPUe热性能和力学性能的影响。随着木质素含量的增加，LPUe表现出改善的热稳定性，并且玻璃化转变温度（T-g）也增加，特别是对于来自具有600 g mol（-1）的低木质素分子量的木质素的LPUe（600-LPUe）。此外，LPUe还具有优异的机械性能。对于具有40wt%木质素的600-LPUe，杨氏模量、拉伸强度和断裂应变分别达到176.4MPa、33.0MPa和1394%，这可以归因于低分子量木质素在弹性体中的更好的分散，如从DSC、SEM和TEM研究中显而易见的。我们的研究结果表明，未改性木质素在开发生物基高性能聚氨酯材料中的潜在应用。这与需要木质素改性以制备PU材料的LPUe系统的许多当前研究相反。
Lignin-based polyurethane elastomers (LPUe) with high stiffness, strength, and toughness were facilely prepared by direct cross-linking of unfunctionized lignin as hard segments and poly (propylene glycol) tolylene 2,4-diisocyanate terminated (PPGTDI) as soft domains. The effects of lignin molecular weight (3600 and 600 g mol(-1)) and weight fraction (5-40 wt %) on the thermal and mechanical properties of LPUe were studied. With an increase in lignin content, LPUe exhibited improved thermal stability, and the glass transition temperature (T-g) also increased, especially for LPUe derived from lignin with low lignin molecular weight of 600 g mol(-1) (600-LPUe). Furthermore, LPUe also exhibits excellent mechanical properties. For 600-LPUe with 40 wt % of lignin, the Young's modulus, tensile strength, and strain at break reach 176.4 MPa, 33.0 MPa, and 1394%, respectively, which could be attributed to better dispersion of low molecular weight lignin in elastomers as evident from DSC, SEM, and TEM studies. Our results demonstrate the potential application of unmodified lignin in developing biobased high-performance PU materials. This is in contrast to many current studies of LPUe systems that need lignin modification to prepare PU materials.