orphology transformation during stretching is investigated by SEM forβ-form polypropylene sheets at room temperatere and at low elongation rate.When stress whining or even yielding in specimen has occured

the β-formspherulites did not obviously change

but a lot of crazes and microcracks insidespherulites have developed Perpendicular to the stretching direction.As perfect neckis formed at 60% of drawing strain and microfibrillar structure is created. Thespherulites is broken by interlamellar sliPPage and rotation at stretching direction.