原位聚合法制备吸水膨胀天然橡胶的研究

I摘要采用过硫酸盐/硫代硫酸钠氧化还原引发体系，在天然胶乳中原位引发聚丙烯酸钠聚合并接枝到天然橡胶烃上，制备出高吸水性天然橡胶，开辟了一条制备吸水天然橡胶的新途径。考察了引发剂的用量及体系中的氧化剂和还原剂的配比，复合氧化剂间的交互作用，反应温度、时间，吸水单体的用量，交联剂用量等对WSNR的接枝率、接枝效率、吸水倍率、吸水速率等性能的影响，并考察了吸水单体用量、硫化体系、硫磺用量和补强剂对WSNR的吸水性能和物理机械性能的影响，采用红外光谱（FTIR）、差热扫描量热法（DSC）、热重分析（TG/DTG）、动态力学分析（DMA）等分析手段对天然橡胶接枝产物，吸水单体均聚物作了分析表征。实验结果表明：引发剂剂用量、反应温度、时间、和单体用量在制备腻子型吸水膨胀天然橡胶中对天然橡胶的接枝率有显著的影响，在本实验研究范围内的最佳工艺为：反应温度为40℃，反应时间为1小时，引发剂用量为0.50%，单体用量为100%，交联剂用量为2.0×10-4mol。两种过硫酸盐（过硫酸钾—过硫酸铵）间在引发制备腻子型吸水膨胀天然橡胶的接枝反应中具有协同效应。采用多种硫化体系对腻子型吸水膨胀天然橡胶进行硫化，得到吸水膨胀天然橡胶的最佳性能为拉伸强度0.83/MPa、断裂伸长率2230.00%、撕裂应力6.35KN·m-1、首次吸水倍率13.09倍；而补强剂苯乙烯的引入能大大提高吸水膨胀天然橡胶的吸水倍率和反复吸水能力；傅立叶红外光谱分析表明该实验方法能有效地使聚聚丙烯酸钠单体接枝到天然橡胶分子链上；TG和DTG分析表明接枝改性的天然橡胶比天然橡胶的耐热性高；DSC分析表明吸水膨胀天然橡胶的水分主要以“三相态”存在；DMA测试分析表明，随着天然橡胶分子链上接枝的聚聚丙烯酸钠量的增多，橡胶的玻璃化温度随之提高，动态储能摸量也随着增大。关键词：原位聚合聚聚丙烯酸钠吸水膨胀天然橡胶AbstractAkindofwaterswellingnaturalrubberwasmadewithnaturallatexgraftedIIsodiumacrylatebyin-situpolymerization.PersulfatesandSodiumThiosulfatewasusedasredoxinitiator.AnewmethodtoprepareWSRformNaturallatexisfound.Effectofquantityofinitiator、dosageratiobetweenpersulfates、dosageratiobetweenpersulfatesandSodiumThiosulfate、reactiontemperature、reactiontime、crosslinkingagentandthedosageofAANaongraftingratio(GR)、graftingeffection(GE)、waterabsorbingratio(WAR)、waterabsorbingvelocityetcwasstudied,inaddition,effectofthedosageofAANa、curesystems、thedosageofsulfurandstrengtheningagentsonwater-swellingcapacityandphysicalmechanicalpropertieswasstudied.Thestructureandthethermo-propertyofwater-swellingnaturalrubberwerestudiedbyFTIR、TGandDTG.,andthestatesofwaterabsorbedinWSNRwereinvestigatedbyDSC,andtheDynamicstoragemodulusofWSNRwereinvestigatedbyDMA.Theresultsshowthattheeffectwasnoticeablyofquantityofinitiator、dosageratiobetweenpersulfates、dosageratiobetweenpersulfatesandSodiumThiosulfate、reactiontemperature、reactiontime、crosslinkingagentandthedosageofNaAAonGR、GEandWAR.Andasynergisticfunctionofinitiatorsininitiatingefficiencywerefoundintheapplicationof(NH4)2S2O8andK2S2O8.Theoptimumreactiveconditiononthegraftingrateandefficiencyofacrylatemonomerisasfollows:reactiontemperature45℃,thequantityofinitiator0.5%,thereactiontime1.5h,thequantityratioofAANa100%,thequantityofcrosslinkingagent2.0×10-4mol.ThephysicalmechanicalpropertiesofWSNRwitchwascueingbyhalf-validcuresystemarefollow:tensilestrengthis0.83/MPa、elongationatbrokenis2203.00%、tearstressis6.35KN·m-1、WARis1309%；thewater-swellingcapacityofWSNRwasimproveoutstandingbypolymerizewithstyrene;FTIRshowsthatnaturalrubbermoleculeisgraftedwithPolyacrylate;TG、TGAshowthatthethermalstabilityofNRisincreasebygraftedwithPolyacrylate;DSCshowsthathasthreedifferentstateswaterintheWSNRandtheDMAshowsthatDynamicstoragemodulusofNRhasimprovedbygraftedwithPolyacrylate.Keywords:In-stiuPolymerazitionPoly-acrylatewater-swellingnaturalrubberi目录摘要………………………………………………………….…iABSTRACT………………………………………………….…i1前言..............................................................................................................错误!未定义书签。1.1吸水橡胶的发展历史与现状....................................................................错误!未定义书签。1.1.1国外吸水橡胶的研究进展......................................................................错误!未定义书签。1.1.2国内吸水橡胶的研究进展......................................................................错误!未定义书签。1.1.3吸水橡胶的工业化生产.......................................................................错误!未定义书签。1.2主体材料的选择.........................................................................................错误!未定义书签。1.2.1橡胶的选择.............................................................................................错误!未定义书签。1.2.2吸水单体的选择.....................................................................................错误!未定义书签。1.3吸水橡胶的制备方法................................................................................错误!未定义书签。1.3.1物理共混法..............................................................................................错误!未定义书签。1.3.2化学接枝.................................................................................................错误!未定义书签。1.3.3物理共混与化学接枝结合法.................................................................错误!未定义书签。1.4吸水膨胀橡胶的应用.................................................................................错误!未定义书签。1.4.1土建工程.................................................................................................错误!未定义书签。1.4.2水敏传感器、医用和生理等方面.........................................................错误!未定义书签。1.4.3保护套的应用..........................................................................................错误!未定义书签。1.5吸水膨胀应用中存在的问题.....................................................................错误!未定义书签。1.5.1吸水膨胀橡胶膨胀的方向性..................................................................错误!未定义书签。1.5.2膨胀倍率..................................................................................................错误!未定义书签。1.5.3膨胀速度..................................................................................................错误!未定义书签。1.5.4析出物..............................................................................................