Ferulic acid-based reactive core-shell latex by seeded emulsion polymerization
Ferulic acid-based reactive core-shell latex by seeded emulsion polymerization
复制标题
种子乳液聚合阿魏酸基反应性核壳胶乳
DOI：
10.1039/c9py00079h
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发表时间：
2019
影响因子：
4.6
通讯作者：
Sylvain Caillol
中科院分区：
文献类型：
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作者：
Wing Sze Jennifer Li;Vincent Ladmiral;Hisaaki Takeshima;Kotaro Satoh;Masami Kamigaito;Mona Semsarilar;Claire Negrell;Patrick Lacroix-Desmazes;Sylvain Caillol
最近重新审视的一种生物基苯乙烯单体，乙酰基保护的 4-乙烯基愈创木酚 (AC4VG)，被用于合成部分生物基的功能性核壳聚合物。采用两步种子自由基乳液聚合工艺制备了具有 PAC4VG 壳的 P(S-co-BA)@PAC4VG 和 PBA@PAC4VG 乳胶颗粒。首先合成 P(S-co-BA) 和 PBA 种子颗粒，随后随着时间的推移将 AC4VG 单体作为预乳液添加。使用过硫酸铵作为自由基引发剂和十二烷基硫酸钠作为表面活性剂，在80℃下以10wt%固体进行水乳液聚合。这些聚合反应产生了具有高单体转化率（> 95%）的胶体稳定乳胶。所得颗粒直径为 80-90 nm（平均强度），TEM 观察显示核壳和部分封装的颗粒形态。 P(S-co-BA)@PAC4VG 乳胶中高达 70% 的 PAC4VG 乙酰氧基在温和碱性条件下经过 18 小时脱保护，生成表面装饰有酚基官能团的核壳聚合物。该脱保护程序不会对胶乳的粒径或胶体稳定性产生不利影响。最后，通过与乙二醛（一种天然来源的二醛）交联，由这些功能性核壳颗粒产生部分生物基酚醛网络（酚醛树脂）。
A recently revisited biobased styrenic monomer, acetyl-protected 4-vinylguaiacol (AC4VG), was used for the synthesis of partially biobased, functional core–shell polymers. P(S-co-BA)@PAC4VG and PBA@PAC4VG latex particles with a PAC4VG shell were prepared using a two-step seeded radical emulsion polymerization process. The P(S-co-BA) and PBA seed particles were synthesized first, and the AC4VG monomer was subsequently added as a pre-emulsion over time. The aqueous emulsion polymerizations were carried out at 10 wt% solids at 80 °C using ammonium persulfate as a radical initiator and sodium dodecyl sulfate as a surfactant. These polymerizations resulted in colloidally stable latexes with high monomer conversions (>95%). The resulting particles were 80–90 nm in diameter (intensity-average) and TEM observations revealed core–shell and partially encapsulated particle morphologies. Up to 70% of the acetoxy groups of PAC4VG in the P(S-co-BA)@PAC4VG latex were deprotected under mild basic conditions over 18 hours to produce core–shell polymers decorated with phenolic functions on their surface. This deprotection procedure did not adversely affect the particle size or colloidal stability of the latex. Finally, partially biobased phenolic networks (phenolic resins) were produced from these functional core–shell particles by crosslinking with glyoxal, a naturally-sourced dialdehyde.