Differential thermal analysis of polybutene‐1

The three polymorphic forms of polybutone‐1 may be easily characterized by DTA: Form I has a DTA peak near 132°C; Form II has a peak near 118°C; and Form III has doublet peaks at 104° and 118°C. The kinetics of the room temperature transformation of Form II to Form I have been qualitatively investigated by DTA. The results indicate: (1) the thinner the film the faster the conversion rate and (2) the greater the catalysis residue in the system, the faster the conversion to Form I. The doublet in the Form III thermogram is due to the fact that the 104°C. transition corresponds to a phase change III to II with the 118°C. transition merely being the normal melting transition of Form II. Indeed, it is possible to heat Form III polybutene to 110°C, quench; and on standing it is found that the product has reverted to Form I.