Thermal behaviors of vinyl esters of long-chain fatty acids and their comblike polymers

Phase transition behaviors of vinyl esters of long-chain fatty acids (C₁₂–C₁₈) and their comblike polymers have been investigated by the thermal analysis combining with X-ray diffraction and infrared spectroscopy. Effect of the length of hydrocarbon chain on the thermal behaviors of both monomers and polymers have been elucidated. Vinyl stearate exhibits three crystalline modifications, α (hexagonal), β₁ (monoclinic, M_∥) and β₂ (monoclinic, O⊥) forms. With shortening of the alkyl chain the polymorphic behaviors become simpler. The thermal behaviors of the resultant polymers are influenced by the packing mode of monomer molecules and the polymerization temperature.