Polyacetaldehyde may exist in atactic , syndiotactic and isotactic forms .
聚乙醛可以以无规，间同和全同形式存在。
The best way to represent the isotactic structure is with molecular models .
表示等规结构的最好方法是用分子模型。
High isotactic poly ( 1-butene ) ( ipb ) was synthesized with ziegler-natta catalyst , and the effects of three external electron donors on polymerization of 1-butene were investigated .
