Analysis of poly(vinyl alcohol) crystallizability: the hindering effect of octa(γ-chloropropyl) POSS

The PVA-g-POSS film was prepared by casting method and the effect of grafting POSS on the crystallization behavior and mechanical properties of PVA film was explored. The corresponding results showed that the crystallinity of PVA-g-POSS films was reduced to an amorphous state. This is because the introduction of POSS increases steric hindrance and it is difficult for PVA molecular chains to be discharged into the crystal lattice. Besides, the crystal growth mode has changed from three-dimensional growth (pure PVA) to a mix of two-dimensional and three-dimensional growth, in which two-dimensional growth mode predominates. Through successive self-nucleation and annealing thermal analysis (SSA), it is found that the wafer size has also changed, and the wafer thickness value has become smaller. Moreover, the eight active sites on POSS made the PVA molecular chain form a stable certain cross-linked structure, which can improve the mechanical properties of the film. In short, the introduction of POSS would hinder the crystallization of PVA, which would affect the performance of PVA products.