MORPHOLOGY SHRINKAGE RELATIONSHIPS IN SEMICRYSTALLINE POLYMERS - EPITAXY, A WAY OF ELIMINATING AMORPHOUS CONTRIBUTION

A new approach for achieving a highly dimensionally stable film of semi-crystalline polymers via blending is demonstrated. To illustrate this approach, a model system, polyethylene-polypropylene is investigated using TEM, TMA, DSC, and DMA. It is shown that epitaxial growth in polymer blends and laminates can induce a cross-hatch morphology which eliminates or reduces the contribution of an oriented amorphous phase. This ultimately leads to greater dimensional stability and synergism in mechanical properties as well. The presence of an appropriate low-melting component can also be used to reduce shrinkage.