Preparation And Properties Of Polyurethane Elastomers Containing Oligo (Ethylene Oxide) Monomethyl Ether Side Chains

In this dissertation, the intermediate products with different length ofoligo(ethylene oxide) monomethyl ether side chains,1-brom-(ethylene oxide)nmonomethyl ether (n=2,3,4)and oligo (ethylene oxide)nmonomethyl ether–toluenesulfonate (n=1,8,11,12,16) were synthesized by the reaction ofCH3(OCH2CH2)nOH (n=1,2,3,4,8,11,12,16), paratoluensulfonyl chloride,carbontetrabromide and triphenylphosphine.Then the eight kinds of novel diols, N-mpeodiethanolamine(n=1,2,3,4,8,11,12,16) were synthesized by the reaction ofdiethanolamine, the corresponding bromide or toluenesulfonate. Two series ofpolyurethane elastomers with different length of oligo(ethylene oxide)nmonomethylether side chains were prepared by the reaction of TDI, PTMG-1000or PEA-1000,N-mpeo diethanolamine (n=1,2,3,4,8,11,12,16) and MOCA. The effect of thedifferent length of side chains on mechanical properties, thermal properties,dynamical mechanical properties and micromorphology of PTMG-based andPEA-based PUEs was systematacially studied.The results of mechanical properties showed that the tensile strength of the twoseries of PUEs increased significantly with the introduction of oligo(ethylene oxide)nmonomethyl ether side chain (n=1) compared with blank samples. The general trendwas that the tensile strength slowly decreased as increasing the side chain length. Theresults of dynamical mechanical properties showed that the incorporation ofoligo(ethylene oxide)nmonomethyl ether side chains was beneficial to reduce therolling resistance and improve wet-skid resistance of PTMG-based PUEs.While inthe serie of PEA-based PUEs, the damping temperature range was broader towardshigh temperature with the introduction of oligo(ethylene oxide)nmonomethyl etherside chains（n=1,2,3,4,8）, the magnitudes of tanδ were larger and correspondingtemperature range became broader toward two directions than blank samples whenintroducing longer ethylene oxide monomethyl ether side chains（nn=11,12,16）,which indicated that PEA-based PUEs with oligo(ethylene oxide)nmonomethyl ether sidechains side chains had potential applications as damping materials. The results ofDSC and DMA showed that the Tg of the two series of PUEs approximately shiftedtoward higher temperature then back to lower temperature with increasing the lengthof side chains.The results of ATR FT-IR spectrum and Low Field NMR all proved that thehydrogen-bond interaction in hard segments of PTMG-based and PEA-based PUEsincreased significantly with the introduction of oligo(ethylene oxide)nmonomethylether side chains side chain(n=1), then slowly decreased as increasing the side chainlength.Besides, the general trend of the crosslinking density of the two series of PUEsdetermined by equilibrium swelling method and Low Field NMR was almost thesame, the crosslinking density of the two series of PUEs increased with theintroduction of short ethylene oxide monomethyl ether side chain, then slowlydecreased when increasing the side chain length.The results of XRD indicated PTMG-based and PEA-based PUEs witholigo(ethylene oxide)nmonomethyl ether side chains all exhibited dominantamorphous state, and the distance between the crosslinking network graduallyincreased with the increase of the side chain length. The results of AFM revealed thatthe degree of phase separation of PUEs with oligo(ethylene oxide)nmonomethyl etherside chains improved significantly with the introduction of oligo(ethylene oxide)nmonomethyl ether side chains (n=1)and then decreased with increasing the length ofside chains.