1, the rigidity of the molecular chain

The molecular chain of more rigid, melt viscosity and high polymer molecular chain movement is poor, so the high elastic deformation produced by the reversible recovery is poor, easy to produce residual stress and for example, some molecular chain containing benzene polymer, such as PC, PPO, PPS, stress the corresponding products is too large.

2, the polar molecular chain

A molecular chain with higher polarity of intermolecular forces attract each other more, so that the molecules to each other to move hard recovery increases, reversible elastic deformation degree decreases, resulting in large residual stress. For example, some of the molecular chain containing carbonyl, ester, eye base polar groups such as plastic types, the corresponding products of the large internal stress.

3. Steric hindrance effect of substituted groups

Molecular side substituted groups of larger size, while impairing the macromolecular chain free activity leads to residual stress increase.For example, the phenyl substituent of polystyrene is larger, and the residual stress of polystyrene products. The following stress in order of the size of several common polymers: PPO>PSF>PC>ABS>PA6>PP>HDPE