1. Thus atactic polystyrene is amorphous but isotactic polystyrene is semi-crystalline.

2. Polyacetadehyde may exist in atactic, syndiotactic and isotactic forms.

3. Polyacetaldehyde may exist in atactic, syndiotactic and isotactic forms.

4. The best way to represent the isotactic structure is with molecular models.

5. Isotactic diad decreases with the increase of radiation dose . Meanwhile, atactic and syndiotactic diad increases.

6. Isotactic polypropylene ( iPP ) flat sheet microporous membranes were prepared via thermally induced phase separation ( TIPS ).

7. High isotactic polybutene-1(HIPB-1)was chlorinated by aqueous suspension method. Chlorination products CHIPB-1 were tested and analyzed through DSC.