Morphology Control of Aromatic Polymers during Polymerization

Morphology and formation mechanism of poly (4'-oxy-4-biphenylcarbonyl) (POBP) crystals obtained by solution polymerization were firstly treated. It was concluded that the formation mechanism of the bundlelike aggregates of fibrillar crystals in POBP was fundamentally simillar to that in POB whiskers. Secondly the copolymerization effects of m-acetoxybenzoic acid and 4-(4-acetoxyphenyl) benzoic acid on the morphology of POB whiskers were studied. The experimental results strongly supported our proposal for the formation mechanism of whiskers which was consisted of crystallization of oligomers with a critical length as lamellae from solution and solid state polymerizationof oligomers between lamellae. Finally, the formation mechanism of poly (p-oxycinnamoyl) spherical products during solution polymerization was treated. The formation of these spherical products could be understood by overlapped phase diagram of melting depression curve and consolute curve of oligomers-solvent system.