摘要
对顺-1,4含量为100%的高顺式聚异戊二烯(HCPI)进行加氢反应,得到了序列结构高度规整的乙烯-丙烯交替共聚物(alt-EP).所用的HCPI有适当的分子量(Mn=41×104)和极窄的分子量分布(Mw/Mn=1.02).HCPI的加氢反应以环烷酸镍和三异丁基铝为催化剂,在60℃和4.0MPa氢压的条件下反应3h,加氢产物的加氢度为100%.GPC测试结果显示所得乙烯-丙烯交替共聚物保持了窄分布的特点,表明HCPI加氢后未发生交联和降解反应;NMR,FTIR和广角X射线衍射测试结果表明此乙烯-丙烯交替共聚物具有高度规整的序列结构,为完全交替结构的乙烯-丙烯共聚物.并通过TGA和DSC对乙烯-丙烯交替共聚物的热性能进行了表征.
Alternating ethylene-propylene copolymer （alt-EP ） was synthesized by hydrogenation of polyisoprene （HCPI） having high cis-1,4 content （ca.100% ）,suitable molecular weight （Mn = 41 × 104）,and relatively narrow molecular weight distribution （Mw/Mn = 1.02）.The hydrogenation of HCPI was carried out with Ni（naph）2/Al（i-Bu）3 catalyst at 60℃ and hydrogen pressure of 4.0 MPa in cyclohexane for 3 h.NMR and FTIR spectra showed that the characteristic peaks of carbon-carbon double bond disappeared in hydrogenated HCPI,indicating that the hydrogenation degree of the resulting polymer was up to 100% .GPC analysis indicated that the alt-EP maintained relatively narrow molecular weight distribution （Mw/Mn = 1.12）,and degradation or crosslinking reaction did not occur during hydrogenation reaction of HCPI.NMR and FTIR spectra as well as WAXD analysis showed that the alt-EP was well-defined ethylene-propylene copolymer having high alternation,and the present completely alternating ethylene and propylene copolymer was synthesized for the first time.Further,the thermal properties of HCPI and alt-EP were examined by TGA and DSC.The glass transition temperature of alt-EP was-63.3℃ ,whose value is larger than that of HCPI （-66.7℃ ）.The onset temperature of weight loss of alt-EP was 355℃ and much higher than that of HCPI （266℃ ）,which suggesting that the thermal stability is enhanced upon hydrogenation.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2010年第8期961-965,共5页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号20674007
20774015)资助项目
