Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada; Laboratoire de Chimie des Polymères Organiques, Université de Bordeaux, 16 avenue Pey-Berland, F-33600 Pessac, France.
Department of Chemistry, Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
Carbohydr Polym. 2019 Feb 1;205:322-329. doi: 10.1016/j.carbpol.2018.10.050. Epub 2018 Oct 25.
Both Surface-Initiated Atom Transfer Radical Polymerization (SI-ATRP) and Surface-Initiated Activator Re-Generated by Electron Transfer ATRP (SI-ARGET ATRP) were performed to graft polystyrene and poly(4-vinylpyridine) on the surface of cellulose nanocrystals (CNCs) to evaluate the potential benefits of each method. The polymer grafted CNCs and their corresponding free polymers initiated from sacrificial initiators were characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, dynamic light scattering, differential scanning calorimetry, thermogravimetric analysis, and elemental analysis, respectively. It was found that SI-ARGET ATRP favored the grafting of longer polymer chains with lower grafting density compared with the classical SI-ATRP. The surface initiation efficiency of brominated CNCs in SI-ARGET ATRP is much lower than that in SI-ATRP, which is mainly due to the much lower amount (ppm level) of catalysts and faster propagation rate in SI-ARGET ATRP system.
同时进行了表面引发原子转移自由基聚合（SI-ATRP）和表面引发电子转移再生原子转移自由基聚合（SI-ARGET ATRP），以将聚苯乙烯和聚（4-乙烯基吡啶）接枝到纤维素纳米晶体（CNC）表面，评估每种方法的潜在优势。通过傅里叶变换红外光谱、凝胶渗透色谱、动态光散射、差示扫描量热法和热重分析以及元素分析分别对接枝 CNC 的聚合物及其相应的从牺牲引发剂引发的游离聚合物进行了表征。结果发现，与经典的 SI-ATRP 相比，SI-ARGET ATRP 有利于较长聚合物链的接枝，接枝密度较低。在 SI-ARGET ATRP 中，溴化 CNC 的表面引发效率远低于 SI-ATRP，这主要是由于在 SI-ARGET ATRP 体系中催化剂的用量（ppm 级）要低得多，且增长速率更快。
