【摘要】 以磺化木质素黄原酸酯（lignin-CTA）为链转移剂，与甲基丙烯酸甲酯（MMA）进行可逆加成-断裂链转移（RAFT）乳液聚合，并将得到的木质素-聚甲基丙烯酸甲酯（lignin-g-PMMA）接枝共聚物作为大分子链转移剂，然后加入甲基丙烯酸月桂酯（LMA）进行扩链反应，合成一种具有压敏性能的木质素基嵌段共聚物（lignin-g-PMMA-b-PLMA）,并探究了其对豆粕胶黏剂初黏性的影响。红外光谱（FT-IR）、核磁共振氢谱（¹H NMR）、凝胶渗透色谱（GPC）及差示扫描量热（DSC）分析结果均证实了LMA与lignin-g-PMMA反应形成了嵌段共聚物，所得lignin-g-PMMA-b-PLMA的红外光谱图在1 729 cm^-1处有MMA中酯基的振动吸收峰，2 922、 2 853 cm^-1处有—CH₂—吸收峰，¹H NMR谱图中δ 3.57处有PMMA中—OCH₃的氢质子峰，δ 4.04处有PLMA中—O—CH₂—的氢质子峰；相比lignin-g-PMMA,嵌段共聚物的相对分子质量显著增加，平均粒径有所增大，相对分子质量分布变宽（PDI为2.68）,玻璃化转变温度（T_g）为-24℃,低于lignin-g-PMMA的114℃。“环形法”测试发现嵌段共聚物的最大拉力值为0.79 N,显示出一定压敏性，将其用于改性豆粕胶黏剂的饰面板贴面实验，lignin-g-PMMA-b-PLMA乳液的添加量为10%时，饰面板不会产生翘曲，说明改性后豆粕胶的初黏性有了较大的改善。更多还原

【Abstract】 Sulfonated lignin xanthate（lignin-CTA） was used as a chain transfer agent for the reversible addition-fragmentation chain transfer（RAFT） emulsion polymerization of methyl methacrylate（MMA）. The obtained lignin-g-PMMA graft copolymer was further employed as a macromolecular chain transfer agent, and then lauryl methacrylate（LMA） was added for chain extension reaction to synthesize a lignin-based block copolymer（lignin-g-PMMA-b-PLMA） with pressure-sensitive property. The effect of this block copolymer on the initial adhesion of soybean meal adhesive was also investigated. The analysis results of FT-IR, ¹H NMR, GPC and DSC all confirmed that LMA reacted with lignin-g-PMMA to form a block copolymer. The FT-IR spectrum of obtained lignin-g-PMMA-b-PLMA showed that the vibration absorption peak of ester group in MMA segment appeared near 1 729 cm^-1, and the absorption peak of —CH₂— appeared at 2 922 and 2 853 cm^-1. The ¹H NMR spectrum displayed a hydrogen proton peak of —OCH₃ from PMMA at δ 3.57 and a hydrogen proton peak of —O—CH₂— from PLMA at δ 4.04. The block copolymer exhibited a significantly increased relative molecular mass, larger average particle size, broader relative molecular mass distribution（PDI=2.68）, and a lower glass transition temperature（T_g=-24 ℃） compared with lignin-g-PMMA（T_g=114 ℃）. The maximum force value of block copolymer tested via the loop tack test was 0.79 N, indicating certain pressure sensitivity. It was used in the veneering experiment for modifying soybean meal adhesives. The results showed that the decorative veneer would not warp when 10% block copolymer emulsion was added into soybean meal adhesive, showing that the initial tack of modified adhesive had been greatly improved.更多还原