Ostmark Emma, Harrisson Simon, Wooley Karen L, Malmström Eva E
Royal Institute of Technology, KTH Fibre and Polymer Technology, Teknikringen 56-58, 100 44 Stockholm, Sweden.
Biomacromolecules. 2007 Apr;8(4):1138-48. doi: 10.1021/bm061043w. Epub 2007 Mar 17.
Hydroxypropyl cellulose (HPC) was used as a core molecule for controlled grafting of monomers by ATRP, the aim being to produce densely grafted comb polymers. HPC was either allowed to react with an ATRP initiator or the first generation initiator-functionalized 2,2-bis(methylol)propionic acid dendron to create macroinitiators having high degrees of functionality. The macroinitiators were then "grafted from" using ATRP of methyl methacrylate (MMA) or hexadecyl methacrylate. Block copolymers were obtained by chain extending PMMA-grafted HPCs via the ATRP of tert-butyl acrylate. Subsequent selective acidolysis of the tert-butyl ester moieties was performed to form a block of poly(acrylic acid) resulting in amphiphilic block copolymer grafts. The graft copolymers were characterized by 1H NMR and FT-IR spectroscopies, DSC, TGA, rheological measurements, DLS, and tapping mode AFM on samples spin coated upon mica. It was found that the comb (co)polymers were in the nanometer size range and that the dendronization had an interesting effect on the rheological properties.
羟丙基纤维素（HPC）被用作通过原子转移自由基聚合（ATRP）进行单体可控接枝的核心分子，目的是制备高密度接枝的梳状聚合物。使HPC与ATRP引发剂或第一代引发剂功能化的2,2-双（羟甲基）丙酸树枝状分子反应，以生成具有高官能度的大分子引发剂。然后使用甲基丙烯酸甲酯（MMA）或甲基丙烯酸十六酯的ATRP从大分子引发剂“接枝生长”。通过丙烯酸叔丁酯的ATRP使接枝了聚甲基丙烯酸甲酯（PMMA）的HPC进行链增长，从而获得嵌段共聚物。随后对叔丁酯部分进行选择性酸解，以形成聚丙烯酸嵌段，从而得到两亲性嵌段共聚物接枝物。通过对旋涂在云母上的样品进行1H NMR和FT-IR光谱、DSC、TGA、流变学测量、DLS和敲击模式原子力显微镜对接枝共聚物进行了表征。发现梳状（共）聚合物处于纳米尺寸范围，并且树枝状化对接枝共聚物的流变性能有显著影响。
