The copolymer of polyvinyl acetate containing lignin-vinyl acetate monomer: Synthesis and characterization
The copolymer of polyvinyl acetate containing lignin-vinyl acetate monomer: Synthesis and characterization
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DOI：
10.1016/j.eurpolymj.2019.109411
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发表时间：
2020-01
影响因子：
6
通讯作者：
Nana Zhang;Shoujuan Wang;M. Gibril;F. Kong
中科院分区：
文献类型：
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作者：
Nana Zhang;Shoujuan Wang;M. Gibril;F. Kong
木质素单体在聚合物合成中的应用将减少石化单体的使用，提高聚合物/共聚物的性能，并以有利的方式处理木质素。因此，本工作成功地合成了木质素-醋酸乙烯酯单体（LVAc）及其共聚物。为了得到LVAc，首先用二乙烯三胺（DETA）与胺活化木质素，然后在碱介质中与氯乙酸乙烯酯（CVAc）接枝。确定了制备LVAc的最佳条件为40 °C、6 h和pH 9。通过LVAc与乙酸乙烯酯（VAc）单体的悬浮共聚来合成共聚物，其在过氧化苯甲酰（引发剂）存在下在60 °C下进行3 h。采用元素分析、核磁共振氢谱（1HNMR）、X射线光电子能谱（XPS）、凝胶渗透色谱（GPC）、热重分析（TGA）、差示扫描量热法（DSC）和傅里叶变换红外光谱（FTIR）等方法对LVAc及其共聚物进行了表征。GPC分析表明，与PVAc相比，共聚物的分子量（Mw）更高，大于10，000 g/mol。值得一提的是，Mw的增加与木质素含量成正比。TGA和DSC结果显示共聚物的热稳定性有所改善。该研究显示了合成具有高分子量和增强的热性能的乙酸乙烯酯/木质素共聚物的有希望的结果，这意味着这些共聚物（生物基）可用于广泛的应用领域，包括聚乙烯醇（PVA）的前体，油漆膏，涂料膜，以及木材，纸张和纸板的粘合胶。
Application of the lignin-based monomer in polymers synthesis will reducing the use of petrochemical-based monomers, enhance the polymer/copolymers properties, and disposing lignin in a profitable way. Accordingly, in this work, the lignin-vinyl acetate monomer (LVAc) and its copolymers were synthesized successfully. To obtain the LVAc, firstly, lignin was activated with the amine using diethylenetriamine (DETA) and then followed by the grafting with chlorovinyl acetate (CVAc) in alkali medium. The optimal conditions of the preparation the LVAc were determined with the 40 °C, for 6 h, and at pH 9. The copolymers were synthesized through a suspension-copolymerization of the LVAc with vinyl acetate (VAc) monomers, which was carried out at 60 °C for 3 h in the presence of Benzoyl peroxide (initiator). The characterization of the LVAc and its copolymers were done by different methods such as elemental analysis, Proton Nuclear Magnetic Resonance (1HNMR), X-ray photoelectron spectroscopy (XPS), Gel permeation chromatography (GPC), Thermogravimetric analysis (TGA), Differential scanning calorimetric (DSC), and Fourier transform infrared spectroscopy (FTIR). GPC analysis showed that the molecular weight (Mw) for the copolymers was higher with more 10,000 g/mol compared to the PVAc. Worth mention the increasing of Mw was proportional to lignin content. The TGA and DSC results revealed an improvement in the thermal stability of the copolymers. The study showed promising results for synthesis vinyl acetate/lignin copolymers with a high molecular weights and enhanced thermal properties, which implies that these copolymers (bio-based) could be used in a wide area of applications includes precursor for polyvinyl alcohol (PVA), painting paste, coating films, and adhesion glue of wood, paper, and boards.