检索规则说明:AND代表“并且”;OR代表“或者”;NOT代表“不包含”;(注意必须大写,运算符两边需空一格)
检 索 范 例 :范例一: (K=图书馆学 OR K=情报学) AND A=范并思 范例二:J=计算机应用与软件 AND (U=C++ OR U=Basic) NOT M=Visual
机构地区:[1]清华大学化工系教育部先进材料重点实验室,北京100084 [2]日本三洋化成工业株式会社,京都605-0995
出 处:《高分子学报》2009年第1期93-96,共4页Acta Polymerica Sinica
基 金:国家自然科学基金(基金号20574041,20204005,20874055)资助项目
摘 要:合成了以Upy(2-ureido-4[1H]-pyrimidone)封端的超支化聚合物并研究其涂层材料性能.首先在哌嗪与三羟甲基丙烷三丙烯酸酯摩尔比2.25∶1条件下,合成了端仲胺基超支化聚(酯-胺)(HPEA),进而在仲胺基/异氰酸酯基官能团比1∶0.3、1∶0.4和1∶0.5下,通过HPEA与单异氰酸酯基甲基异胞嘧啶反应,合成了一系列带有Upy基元的改性超支化聚合物.由于Upy基元间形成了自识别四重氢键,改性聚合物比HPEA具有更高的玻璃化转变温度和热分解温度,并且改性聚合物涂层具有优良的力学性能,这表明分子间强氢键相互作用可有效改善超支化聚合物的性能.2-ureido-4[ ^1H]-pyrimidone (Upy) telechelic hyperbranched polymers were prepared and their coating performances were investigated. First, a secondary amine terminated hyperbranched poly(ester-amine) (HPEA) was prepared from piperazine and trimethylolpropanetriacrylate at secondary amine/acrylate group ratio of 2.25/1 .At secondary amine/isocyanate stoichiometric ratios of 1 : 0.3, 1 : 0.4 and 1 : 0.5, HPEA was further reacted with monoisocyanato methylisocytosine to give three modified hyperbranched polymers bearing terminal Upy units. Based on the ^1H-NMR spectra of the modified polymers, the degree of modification was calculated, which agreed well with the feeding composition of the components. Due to the formation of self-complementary quadruple hydrogen bonding of Upy groups, the Upy modified polymers possessed improved glass transition temperature ( Tg ) and decomposing temperature ( Td ) compared to HPEA. The coating materials of the modified polymers displayed good mechanical properties. The Tg, Td and coating hardness became higher as increasing the Upy content. All the coatings possessed impact strength of 0.5 kg· m and flexibility of grade 7. This investigation demonstrated that hyperbranched polymers with improved performances could be obtained via incorporating strong hydrogen bonding, which is helpful for designing new dynamic materials.
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在链接到云南高校图书馆文献保障联盟下载...
云南高校图书馆联盟文献共享服务平台 版权所有©
您的IP:216.73.216.28