Preparation Of The Amine-terminated Polyethylene-glycol And Its Blends With Polyolefin

Polyethylene glycol (PEG) is widely used polyether. In many cases, chemical reactions are needed between PEG molecules and some kind of functional groups, so that particular copolymers or stable polymer alloys can be formed. However, the reactivity of the end hydroxyl group at PEG molecule end is low, especially when the molecular weight is high. Therefore, more reactive functional groups, such as amino group, are mostly introduced into PEG molecules. But all the commercialized amine-terminated polyethylene glycols have low molecular weight, less than2000. In many cases, high molecular weight PEG is required, such as anti-absorbing of protein. When the conventional Gabriel Reaction is employed to prepare amine-terminated PEG with high molecular weight, the-NH2transformation ratio is very low, even after quite long reaction time.In this paper, modified Gabriel Reaction was employed to prepare a series of amine-terminated polyethylene glycol (PEG-NH2). The molecular weights of PEG used are2000,4000,5000,6000and20000g/mol. The products were characterized via FTIR,1H NMR, color reaction and elemental analysis; The content of amino group of the different molecular weight PEG-NH2was determined. The results show that about50%of hydroxyl group of polyethylene glycol has been converted into amino group.In addition, the blends of functionalized polyolefin and polyethylene glycol are prepared via reactive blending. The effect of different reactive compatibilization, molecular weight of amine-terminated polyethylene glycol and blend compositions on the morphology of the blends are studied. The results show that the graft copolymerization reaction between-NH2group and-MAH group can significantly improve the compatibility of the blends, which results in relatively smaller dispersed particle size. In particular, PEG-NH26000/PP-PB-MAH (30/70) blend has the trend to form co-continuous morphology.