Desport Jessica S, Moreno Mónica, Barandiaran María J
POLYMAT, University of the Basque Country UPV/EHU, 20018 Donostia-San Sebastián, Spain.
Polymers (Basel). 2018 May 2;10(5):488. doi: 10.3390/polym10050488.
The exploration of a renewable resource for the preparation of waterborne copolymers was conducted. Low molar mass sugar resources were selected for their wide availability. A fructose-based monomer (MF) bearing a methacrylate radically polymerizable group was successfully synthesized. The latter was shown to be able to homopolymerize in emulsion. The high of the resulting polymer (about 115 °C) makes it of particular interest for adhesive and coating applications where hard materials are necessary to ensure valuable properties. As a result, its incorporation in waterborne acrylic containing formulations as an equivalent to petrochemical-based methyl methacrylate was investigated. It was found that the bio-based monomer exhibited similar behavior to that of common methacrylates, as shown by polymerization kinetics and particle size evolution. Furthermore, the homogeneous incorporation of the sugar units into the acrylate chains was confirmed by a unique glass transition temperature in differential scanning calorimeter (DSC). The potential of MF for the production of waterborne copolymers was greatly valued by the successful increase of formulation solids content up to 45 wt %. Interestingly, polymer insolubility in tetrahydrofurane increased with time due to further reactions occurring in storage. Most likely, the partial deprotection of sugar units was the reason for the creation of hydrogen bonding and, thus, physically insoluble entangled chains. This behavior highlights opportunities to make use of hydroxyl groups either for further functionalization or, eventually, for achieving enhanced adhesion on casted substrates.
开展了探索用于制备水性共聚物的可再生资源的研究。选择低摩尔质量的糖类资源是因其广泛可得。成功合成了一种带有甲基丙烯酸酯可自由基聚合基团的基于果糖的单体（MF）。结果表明该单体能够在乳液中进行均聚。所得聚合物的高玻璃化转变温度（约115℃）使其在需要硬质材料以确保具有重要性能的粘合剂和涂料应用中特别受关注。因此，研究了将其作为石化基甲基丙烯酸甲酯的等效物掺入含水性丙烯酸酯的配方中。聚合动力学和粒径演变表明，这种生物基单体表现出与普通甲基丙烯酸酯类似的行为。此外，差示扫描量热仪（DSC）中独特的玻璃化转变温度证实了糖单元均匀地掺入丙烯酸酯链中。通过将配方固体含量成功提高至45 wt％，极大地体现了MF在生产水性共聚物方面的潜力。有趣的是，聚合物在四氢呋喃中的不溶性随时间增加，这是由于储存过程中发生了进一步反应。最有可能的是，糖单元的部分脱保护是形成氢键的原因，从而导致物理上不溶性的缠结链。这种行为凸显了利用羟基进行进一步功能化或最终在浇铸基材上实现增强附着力的机会。
