Question

Based on the molecular structures, compare these polymers based on their properties of stiffness, air-tightness and their resistance to heat! PE, PP, PS, and PVC.

Answer 1

In PE the group attached to C is H. That to PP is methyl, to PS is phenyl and to PVC is chlorine. The properties of these polymers are a consequence of this.

For instance, in PS and PVC there can be better stacking as compared to PP. This is because the phenyl group is planar and chlorine is a single atom attached. But methyl group is tetrahedral thereby the uniformity is lost.

As compared to PE, the thermal stability of PP is also less.

Order is PP < PE < PS < PVC.

The tensile strength of the polymers are in the order

PVC > PS > PP > PE.

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