The initial design of the chemical structure of PIPD aimed at introducing the hydrogen bonds to the rigid-rod polymers.
2]O) and PIPD were synthesized according to the method by Sikkema (2).
PIPD and nylon 6 of a certain weight ratio were dissolved in a mixture of formic acid/methane sulfonic acid (3:1 v/v) forming a homogeneous solution with a concentration of 5 mg polymers per 1 mL solvent.
With such a structure, crystalline PIPD did not melt until its degradation at 500[degrees]C, which was far beyond the decomposition temperature of nylon 6 (12), (13).
It was clear that the presence of PIPD influenced significantly the crystallization and melting behaviors of nylon 6.
The addition of PIPD to nylon 6 shifted the crystallization peak towards lower temperatures.
Unlike the crystallization, the PIPD species was not involved in the melting, since it was rejected from the lattice; consequently, the melting was only related to the lamella of nylon 6.
This indicates the difficulty of nucle-ation in presence of PIPD species.
The inhibition of nucleation by the presence of PIPD was further witnessed by the PLM morphology of crystalline shown in Fig.