Cellulose nanocrystals (CNCs) are sustainable rigid rod-shaped nanoparticles that have potential as reinforcing agents in polymer nanocomposites. CNCs can also act as Pickering stabilizers in emulsions and foams due to their amphiphilic nature. In this work, CNCs were rendered surface active through adsorption with the biopolymer methyl cellulose (MC) to produce MC-coated CNCs. MC-coated CNCs were used to stabilize the microsuspension polymerization of methyl methacrylate. Monomer conversion, latex size, and gel content were studied. The microsuspension polymerization resulted in a double morphology where poly(methyl methacrylate) (PMMA) microparticles and nanoparticles were produced simultaneously. The ratio of micro- to nanoparticles could be tuned based on the CNC:MC ratio. Most nanoparticles were attached to the microparticles offering hierarchically structured latexes, although approximately 2 wt % were free in suspension. Drying conditions could be used to control the surface roughness of the dry latex particles. This work provides a new strategy for the incorporation of CNCs into polymer latexes and the ability to control their morphology. This method could be used to produce CNC-based adhesives, toners, cosmetics, and coatings, providing a greener route compared to solvent-based polymerization while replacing synthetic surfactants with CNCs and MC which are derived from renewable resources.

中文翻译：

---

纤维素纳米晶体和甲基纤维素作为稳定剂的双形态纳米复合乳胶

纤维素纳米晶体（CNC）是可持续的刚性棒状纳米颗粒，在聚合物纳米复合材料中具有作为增强剂的潜力。由于具有两亲性，CNC还可在乳液和泡沫中用作Pickering稳定剂。在这项工作中，CNC通过与生物聚合物甲基纤维素（MC）吸附而具有表面活性，从而生产出MC涂层的CNC。MC涂层的CNCs用于稳定甲基丙烯酸甲酯的微悬浮聚合。研究了单体转化率，胶乳尺寸和凝胶含量。微悬浮聚合产生双重形态，其中聚（甲基丙烯酸甲酯）（PMMA）微粒和纳米颗粒同时产生。可以根据CNC：MC的比例来调整微颗粒与纳米颗粒的比例。大多数纳米颗粒附着在提供分层结构胶乳的微粒上，尽管大约2 wt％的悬浮液中没有。干燥条件可用于控制干燥的乳胶颗粒的表面粗糙度。这项工作为将CNC控制器整合到聚合物胶乳中以及控制其形态的能力提供了新的策略。该方法可用于生产基于CNC的粘合剂，调色剂，化妆品和涂料，与基于溶剂的聚合相比，它提供了一条更绿色的途径，同时用可再生资源衍生的CNC和MC替代了合成表面活性剂。这项工作为将CNC控制器整合到聚合物胶乳中以及控制其形态的能力提供了新的策略。该方法可用于生产基于CNC的粘合剂，调色剂，化妆品和涂料，与基于溶剂的聚合相比，它提供了一条更绿色的途径，同时用可再生资源衍生的CNC和MC替代了合成表面活性剂。这项工作为将CNC控制器整合到聚合物胶乳中以及控制其形态的能力提供了新的策略。该方法可用于生产基于CNC的粘合剂，调色剂，化妆品和涂料，与基于溶剂的聚合相比，它提供了一条更绿色的途径，同时用可再生资源衍生的CNC和MC替代了合成表面活性剂。