Study On Solution Self-Assembly Behavior Of Polyvinyl Hybrid Block Polymers

The hyperbranched structure in hybrid block polymers have a large number of terminals.Polyethylene was bonded to hyperbranched blocks with different terminals through covalent bonds,polyethylene-based hybrid block polymers were designed and synthesized,which enriched the topological structure of polyethylene-based block polymers.It has theoretical research and potential application value in solution self-assembly of polymers.This paper consists of three parts:1.Polyethylene-based hybrid block polymers PE₁-b-hbPG_{?7 or 26?}with different hyperbranched ratios were prepared by coordination polymerization and ring-opening polymerization.The structure and properties of polymers were characterized by NMR,GPC,FTIR,TGA and DSC,and the effects of hyperbranching ratio on solution self-assembly of polymers by changing the types of selective solvents were investigated by means of SEM,TEM,AFM and DLS.The results showed that crystallization driving of polyethylene and hydrogen bonding between hydroxyl terminal groups promoted the formation of perfect diamond lamellae in pure toluene solvents,and the number of end groups affected the morphology of polymers in mixed solvents.2.Polymers PE₁-b-hbPG-acetyl_{?50%or 100%?}were synthesized by acetylating the terminal of above-mentioned hybrid block polymers with different degrees.The structure and properties of the polymer were characterized by ¹H-NMR,FTIR,TGA and DSC.By changing the volume ratio and type of mixed solvents,the effect of the change of terminal group type on the solution self-assembly of the polymer was investigated by SEM,TEM and DLS.The results showed that the hydrogen bonding effect of terminal hydroxyl groups was destroyed as they were continuously converted to ethyl groups.The crystallization of polyethylene was not enough to make the polymers self-assembled into perfect lamellae in pure toluene.Hyperbranched terminal groups were closely related to self-assembled morphologies,which promoted the formation of diverse morphologies of polymers in mixed solvent systems.3.Polymers PE₁-b-hbPG₂₆-acetyl/hexanoyl/stearoyl with different terminal alkyl chain were prepared by esterification reaction.The structure and properties of the polymer were characterized by ¹H-NMR,FTIR,TGA and DSC.By changing the type and volume ratio of mixed solvents,the influence of the length of alkyl chain at the terminal of hybrid block polymer on the solution self-assembly of polymer was investigated by means of SEM,TEM and DLS.The results showed that polyethylene crystallized rapidly in pure toluene solvents,and could drive the incomplete crystallization of hybrid block polymers with terminal alkyl chain.In addition,the crystallinity of polymers decreased with the increase of the length of the terminal alkyl chain.The change of the length of alkyl chain at the terminal would promote the self-assembly of polymers into interesting morphologies in different mixed solvents.In summary,hybrid block polymers with different terminal structures were synthesized based on polyethylene?PE?and hyperbranched glycidyl?hbPG?blocks by coordination polymerization and ring-opening polymerization.The effect of crystallization of polyethylene and hyperbranched terminal on the solution self-assembly process of polymer was explored by discussing the influence of solvent type and proportion.