阳离子对顺酐化苯乙烯-丁二烯-苯乙烯三嵌段共聚物离聚体性能的影响

Effects of different cations on properties of ionomers of maleated styrene-butadiene-styrene triblock copolymer

将顺酐化苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS)离子化得到含不同阳离子的离聚体,考察了不同阳离子对离聚体热性能、物理机械性能、耐油性能和粘接性能的影响。结果表明,离聚体有3个玻璃化转变温度(Tg),其中2个是SBS固有的Tg,另一个是离子微区的离解温度;对于含1价阳离子的离聚体,离子电离势越高,离聚体的离解温度、拉伸强度和搭接剪切强度基本越高,即从大到小依次为含锂离聚体、含钠离聚体、含钾离聚体;含2价阳离子离聚体的离解温度从大到小依次为含钙离聚体、含锌离聚体、含铅离聚体;拉伸强度从大到小依次为含钙离聚体、含锌离聚体、含镁离聚体,且均小于含1价阳离子离聚体;含2价阳离子离聚体的耐油性能优于含1价阳离子离聚体和SBS;含锌离聚体的粘接性能尤为突出,搭接剪切强度达到0.594 MPa。

The ionomers containing different cations,such as sodium,lithium,potassium,calcium,zinc,lead,magnesium,and ethyl ammonium were synthesized from the ionization of maleated styrene-butadiene-styrene triblock copolymer（SBS）.Effects of different cations on the thermal,mechanical,oil resistance and adhesive properties of the ionomers were studied.The results showed that,in addition to the glass transition temperatures（Tg） of butadiene and styrene blocks,the ionomers exhibited third Tg,which is due to the dissociation of the ionic domains.For the monovalent alkali metal cation neutralized ionomers,the higher the ionic potential,the higher the dissociation temperature of ionic domains,tensile strength and lap shear strength to iron plates and the order from large to small was Li＋ Na＋ K＋;for the divalent cation neutralized ionomers,the dissociation temperature of ionic domains decreased in the order of Ca2＋ Zn2＋ Pb2＋,whereas the tensile strength decreased in the order of Ca2＋ Zn2＋Mg2＋,but all were lower than those of the monovalent alkali metal cation neutralized ionomers.The oil resistance of the divalent cation neutralized ionomers was better than that of the monovalent cation neutralized ionomers or SBS.The lap shear strength of zinc ion neutralized ionomer to iron plates was the highest of all,being 0.594 MPa.