Institute of Chemical Industry of Forest Products, CAF, China.
Int J Biol Macromol. 2013 Sep;60:309-15. doi: 10.1016/j.ijbiomac.2013.06.005. Epub 2013 Jun 14.
Copolymerization of butyl methacrylate (BMA) with biobutanol lignin (BBL) was achieved by free-radical polymerization (FRP) using a lignin-based macromonomer. The lignin-based macromonomer containing acrylic groups was prepared by reacting acryloyl chloride with biobutanol lignin using triethylamine (TEA) as absorb acid agentin. From the results of elemental analysis and GPC, the average degree of polymerization (DP) of BBL was estimated to be five. A detailed molecular characterization has been performed, including techniques such as (1)H NMR, (13)C NMR and UV-vis spectroscopies, which provided quantitative information about the composition of the copolymers. The changes in the solubility of lignin-g-poly(BMA) copolymers in ethyl ether were dependent on the length of poly(BMA) side chain. TGA analysis indicated that the lignin-containing poly(BMA) graft copolymers exhibited high thermal stability. The bulky aromatic group of lignin increased the glass-transition temperature of poly(BMA). In order to confirm the main structure of copolymer, (AC-g-BBL)-co-BMA copolymer was also synthesized by atom transfer radical polymerization (ATRP), and the results revealed that the copolymer prepared by ATRP had the same solution behavior as that prepared by FRP, and the lignin-based macromonomer showed no homopolymerizability due to the steric hindrance. In addition, the lignin-co-BMA copolymer had a surprisingly higher molecular weight than poly(BMA) under the same reaction condition, suggesting that a branched lignin based polymer could be formed.
采用基于木质素的大分子单体通过自由基聚合（FRP）实现了甲基丙烯酸丁酯（BMA）与生物丁醇木质素（BBL）的共聚。含有丙烯酸酯基团的基于木质素的大分子单体是通过用三乙胺（TEA）作为吸收酸剂用丙烯酰氯与生物丁醇木质素反应制备的。根据元素分析和 GPC 的结果，估计 BBL 的平均聚合度（DP）为五。已经进行了详细的分子表征，包括（1）H NMR、（13）C NMR 和 UV-vis 光谱等技术，这些技术提供了关于共聚物组成的定量信息。木质素-g-聚（BMA）共聚物在乙醚中的溶解度变化取决于聚（BMA）侧链的长度。TGA 分析表明，含木质素的聚（BMA）接枝共聚物表现出高的热稳定性。木质素的大芳基增加了聚（BMA）的玻璃化转变温度。为了确认共聚物的主要结构，还通过原子转移自由基聚合（ATRP）合成了（AC-g-BBL）-co-BMA 共聚物，结果表明，通过 ATRP 制备的共聚物具有与通过 FRP 制备的共聚物相同的溶液行为，并且由于空间位阻，基于木质素的大分子单体没有均聚合性。此外，木质素-co-BMA 共聚物在相同的反应条件下具有比聚（BMA）高得多的分子量，这表明可以形成支化的木质素基聚合物。
