The role of the hydrogen bonding network for the shear modulus of PIPD

The hydrogen bonding network plays a crucial-but indirect-role in explaining the high compressive strength. It replaces the weak components of the lateral bonding, such as present in many high performance polymer materials with low compressive strength, e.g. PBO and PBZT, with much stronger hydrogen bonds. This makes that in PIPD the relatively strong π-π interaction has the weakest resistance against shear.