The Rasearch Of Multi-grafted Copolymer Ps-g-PI Phase Morphology And Transition

Graft copolymer PS-g-PI contains a variety of polymer chain structures. Two different phases can self-assemble into nanostructure of anisotropic orientation. The basic research phase morphology and phase transition of the copolymer is prerequisite of future commercial products with excellent performance. Research on copolymer generally divided into two parts: film and bulk.The thickness of the copolymer thin film has great effects on final phase morphology. Influence factors of thickness include the solution concentration, solvent, spanning speed and time, etc. Central composite design is used for analysis of different parameters corresponding to the thin film thickness.Surface and interface property of basement have an important influence to copolymer self-assembly. When the basement is not selective for one block, microscopic phase structure of the vertical orientation will be obtained. Graphene oxide layer is considered as a neutral base and meanwhile the mixed solvent vapor is floating on the top surface which can control the swelling degree of each block. The top and down neutral surface induce copolymer self-assembly at the same time, making more regular microstructure.The influence factors of phase morphology contain solvent used and heat treatment conditions in the bulk. Phase morphology is often different when you choose different solvent for evaporation. Toluene, cyclohexane and 1,4-dioxane are different selectivity solvent for PS and PI phase, leading to phase morphology discrepancy.The autologous oriented nanopores are simply generated from relaxation of pre-tension sample in the bulk. Well-developed oriented lamellar structure is formed within the autologous oriented nanopores around phase transition temperature. This simple method can greatly improve the degree of orientations in the bulk. No complex prerequisite, our finding is likely generalized to commercial copolymer materials such as SBS or SIS.