摘要
合成了带树枝状聚苯甲醚修饰基团的苯乙炔单体,在Rh[(nbd)Cl2]2催化剂的作用下得到了侧链带聚苯甲醚树枝的新型聚苯乙炔衍生物,用红外吸收光谱、核磁共振谱、紫外可见吸收光谱和凝胶渗透色谱表征了聚合物的结构.发现聚合物的重均分子量达到了57300,在氯仿、N,N-二甲基甲酰胺、四氢呋喃等有机溶剂中有良好的溶解性能.由于侧链上聚苯甲醚树枝体积庞大,聚合物主链采取立构规整的顺-顺式构象,紫外可见吸收光谱在440nm附近出现了显著的共轭主链的吸收肩峰;立构规整的顺-顺式构象使树枝状侧链形成了对主链保护的"夹套效应",聚合物热分解温度从聚苯乙炔母体的225℃提高到295℃.
Polymerization of a phenylacetylene monomer bearing a dendron moiety was carried out by using a rhodium complex Rh [ （nbd） C12 ] 2 as catalyst. The structure of the resultant was characterized with infrared （IR）, nuclear magnetic resonance （NMR）, and UV-Visible absorption spectroscopic techniques; the experimental data confirmed the generation of the expected polyphenylacetylene derivative （P1） with dendron pendants. P1 was soluble in common organic solvents such as chloroform, N, N-dimethylformamide oxide, and tetrahydrofurran （THF）, and its average molecular weight was about 57300. The steric repulsion of between the bulky dendritic side chains make the polymer main-chain take a stereoregular cis-cisoid conformation. Consequently, P1 exhibits a pronounced shoulder at around 440 nm in the absorption spectrum its THF solution. Meanwhile, the bulky dendrons around the polymer main-chain protect the main-chain from thermal-induced decomposition via the ＂jacket effect＂, thus P1 lost 5 % of its weight at a temperature of 295 ℃, which is about 70℃ higher than its parent polymer, or polyphenylacetylene.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2009年第4期293-297,共5页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号20634020,50573065)
国家重点基础研究发展计划(973计划,项目号2002CB613401)资助项目
关键词
官能化聚炔
树枝状聚合物
构象
稳定性
Functional Polyacetylenes, Dendron, Conformation, Stability.
