摘要
用新型催化体系 Ti Cl4,Ti( OBu) 4/Mg Cl2 ,Si O2 和 Zn Cl2 /醇 /Al R3催化乙烯与 1 -丁烯气相均聚及共聚 ,制得两种共聚物弹性体 ,发现新型催化剂体系具有独特的齐聚和原位共聚性能 .采用 1 3C NMR测定了共聚物链序列分布结构 ,观察到共聚单体在聚合物链中分布不均匀 ,存在较长的乙烯链段和较多的 1 -丁烯嵌段 .产物 DSC谱图表现出复杂的结晶熔融行为 ,存在多种结晶形态 ,出现熔融肩峰及双峰 ,与通常制得的LLDPE的结晶熔融行为有很大差别 ;结晶度和密度较低 。
Two elastomers have been prepared by gas copolymerization of ethylene and 1 butene with new highly active catalyst TiCl 4, Ti(OBu) 4/MgCl 2, SiO 2, ZnCl 2/alcohol/AlR 3. Triad sequence and comonomer distributions, average sequence length, run numbers are determined using 13 C NMR. It was found that the new catalyst has the properties to catalyze ethylene and 1 butene oligamerization and copolymerization in situ . The distribution of comonomer 1 butene in copolymers is not homogeneous, and the content of [EBB] + [BBB] in triad sequence distribution of elastomer is higher than that of common LLDPE. The melting and crystallization behavior of products are investigated by the method of DSC. The products show complicated crystallization and melting behavior, and lower melting point, density and degree of crystallinity. These results can be attributed to the existence of more 1 butene blocks in the copolymers chain and their participation in crystallization. The crystallization in copolymers may be physical crosslinking points and the products display the properties of elastomer. [WT5HZ]
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2000年第4期643-646,共4页
Chemical Journal of Chinese Universities
基金
国家自然科学基金 !(批准号 :2 98740 3 9)
]广东省自然科学基金
关键词
齐聚
共聚
乙烯
1-J烯
催化剂
聚乙烯
Oligamerization
Copolymerization
Elastomers
Sequence distribution
Melting behavior