KTH Royal Institute of Technology, School of Chemical Science and Engineering, Department of Fibre and Polymer Technology, Teknikringen 56, SE-100 44 Stockholm, Sweden.
McMaster University, Department of Chemical Engineering, 1280 Main Street West, Hamilton, Ontario L8S 4L7, Canada.
Carbohydr Polym. 2017 Feb 10;157:1033-1040. doi: 10.1016/j.carbpol.2016.10.064. Epub 2016 Oct 21.
In this work we describe the grafting of cellulose nanocrystals (CNCs) by surface-initiated photoinduced Cu-mediated reversible-deactivation radical polymerization (RDRP). Initially, CNCs obtained through sulfuric acid hydrolysis were functionalized with a tertiary bromo-ester moiety as an initiating group for the subsequent RDRP of methyl acrylate, targeting three different degrees of polymerization for the polymer grafts: 50, 300 and 600. The polymerizations proceeded in DMSO in the presence of CuBr and MeTREN as the catalytic system utilizing a UV source (λ≈360nm). The technique proved highly versatile for the modification of CNCs with poly(methyl acrylate), where considerably high grafting was achieved in short reaction times (90min), with simple purification steps. CNC morphology was maintained and polymer grafts were evident through FT-IR spectroscopy, thermal analysis, contact angle measurements, X-ray photoelectron microscopy and x-ray diffraction.
在这项工作中，我们描述了通过表面引发光诱导铜介导的可逆失活自由基聚合（RDRP）接枝纤维素纳米晶体（CNC）。最初，通过硫酸水解获得的 CNC 用叔溴酯部分官能化，作为随后甲基丙烯酸酯的 RDRP 的引发基团，针对聚合物接枝的三个不同聚合度：50、300 和 600。聚合在 DMSO 中进行，在 CuBr 和 MeTREN 作为催化体系的存在下，利用 UV 源（λ≈360nm）。该技术在使用短反应时间（90min）和简单的纯化步骤对 CNC 进行聚甲基丙烯酸甲酯的改性方面非常通用，接枝率高。FT-IR 光谱、热分析、接触角测量、X 射线光电子能谱和 X 射线衍射表明保持了 CNC 的形态，并且可以明显看到聚合物接枝。
