Functional polymers and capsules for innovative paper products

创造具有独特性能的创新纸产品是应对加拿大保持健康和不断增长的造纸行业所面临挑战的最佳方法之一。将开发一系列具有定制结构的新型阳离子聚合物/胶囊，并用作各种增值特种纸产品的功能添加剂或提高现有纸产品的性能。该应用还可以扩展到其他领域，如生物材料和环境修复。本论文的主要研究内容包括三个方面：1）阳离子聚乙烯醇（PVA）的修饰; 2）基于纳米胶囊的星星聚合物的功能化修饰; 3）响应性纳米胶囊和功能化介孔微粒。官能团、侧链和试剂将通过各种现有技术并入聚合物/胶囊中，包括活性自由基聚合、共聚、后接枝和可控负载。这些聚合技术使我们能够通过控制臂组成/数目和侧链长度等参数来制备具有可调性质的聚合物，并合成具有可逆负载和释放功能剂的pH响应性纳米胶囊。由于阳离子和水溶性或可分散的性质，聚合物/胶囊在造纸湿部添加后将与纤维素纤维良好地保持在一起，从而促进它们的应用。 从基础理论的角度建立功能添加剂的结构-性能关系，将为进一步的高分子设计提供指导。星星聚合物的新奇的一部分依赖于功能链和装载的试剂之间的协同作用。除了消毒剂和抗真菌聚合物之外，还可以可控地装载和释放专用染料或荧光探针，从而将应用从抗真菌包装扩展到其他类型（例如，安全纸）。与此同时，具有明确链结构的阳离子PVA将提高我们对聚合物与纤维素纤维相互作用（吸附和渗透）的基本理解，并可能减少纸浆精制过程中所需的能量。

Creating innovative paper products with unique properties is one of the best approaches to address the challenges of maintaining a healthy and growing papermaking industry in Canada. A range of novel cationic polymers/capsules with tailored structures will be developed, and used as functional additives for various value-added specialty paper products or enhancing the performance of existing paper products. The application can also be extended to other areas like biomaterials and environmental remediation. The proposed research consists of three projects: 1) tailor-modified cationic-polyvinyl alcohol (PVA); 2) nanocapsule-based star polymers with functional-modified arms; 3) responsive nanocapsules and functional mesoporous microparticles. The functional groups, pendant chains and agents will be incorporated into polymers/capsules via various state-of-art techniques, including living-free radical polymerization, copolymerization, post-grafting and controllable loading. Those polymerization techniques enable us to prepare the polymers with tuneable properties by manipulating the parameters such as arm composition/numbers and pendant chain lengths, and to synthesize the pH-responsive nanocapsules with reversible loading and release of functional agents. Due to cationic and water-soluble or dispersible nature, the polymers/capsules will be well retained with cellulose fibres after being added at the wet-end of papermaking, thus facilitating their application. The establishment of structure-property relation for functional additives from a fundamental point of view will provide a guide for further macromolecular design. Part of the novelty of star polymers relies on the synergy between functional chains and agents loaded. Apart from disinfectant and antifungi polymers, specialty dye or fluorescent probes could also be controllably loaded and released, thus expanding the application from antifungi packaging to other types (e.g., security paper). Meanwhile, the cationic-PVA with well-defined chain architectures will improve our fundamental understanding of the interaction (adsorption and penetration) of polymers with cellulose fibres, and potentially reduce the energy required in pulp refining processes.