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1、萬方數(shù)據(jù)第23卷第4期2009年8月高?;瘜W工程學報JournalofChemicalEngineeringofChineseUniversitiesNo.4、,oI.23Aug.2009文章編號:1003-9015(2009)04-0650-05水性聚氨酯的交聯(lián)改性及其性能羅眷暉,瞿金清,陳煥欽(華南理工大學化學與化工學院,廣東廣州510640)摘要:陰離子水性聚氨酯(Pu)含有羧基起內乳化劑作用穩(wěn)定水性聚氨酯分散體(PUD),同時也使PU膜具有高的親水性。為提高PUD涂膜性能,采用氮丙啶和聚碳化二亞胺對其進行交聯(lián)改性。利
2、用紅外光譜和熟重分析表征了PUD固化涂膜,結果表明:在室溫下氮丙啶和聚碳化二亞胺可與PUD鏈上的羧基反應,PUD涂膜性能的提高取決于固化劑種類:如氮丙啶能顯著改善涂膜耐水性、耐溶劑性及耐污染性,因其能提高涂膜的凝膠含量至92.63%,涂膜硬度至0.72,其最佳的氮丙啶與羧基的質量比為5.“;另一方面,聚碳化二亞胺能改善涂膜的附著力、柔韌性及抗冷脆性,最佳的聚碳化二亞胺與羧基的質量比為10.37。TGA曲線表明聚碳化二亞胺能提高PUD涂膜的熱穩(wěn)定性,而氮丙啶則降低涂膜的熱穩(wěn)定性。關鍵詞:水性聚氨酯;交聯(lián)改性;氮丙啶;聚碳化二亞
3、胺中圖分類號:TQ630.4文獻標識碼:ACrosslinkingModificationofAqueousPolyurethaneDispersionsanditsPropertiesLUOChun—hui,QuJin—qing,CHENHuan—qin(SchoolofChemistryandChemicalEngineering,SouthChinaUniversityofTechnology,Guangzhou510640,China)Abstract:Anionicaqueouspolyurethane(PU)co
4、ntainsthecarboxylgroupswhichserveasinternalemulsifierstabilizingaqueousPUdispersions(PUD);atthesametime,itcausesthePUDfilmtoexhibitahighhydrophilicity.InordertoimprovetheperformancesofPUDfilm,thePUDswerecrosslinkedbyaziridinederivativesandpolycarbodiimide,respectiv
5、ely.ThecrosslinkedPUDfilmswerecharacterizedbyFT-IRspectrumandthermogravimetricanalysis(TGA);theresultsindicatethattheaziridinederivativesandpolycarbodiimidereactwiththecarboxylgroupsofPUDatroomtemperature.ThepropertiesofthecuredPUDfilmwereimprovedaccordingasthecuri
6、ngagent’Scategoryused.Forexample,theaziridinederivativescanimprovethewater-,solvent-andpollution—resistancepropertiesofthecuredfilmsgreatly;itmaybeattributedtOtheincreaseoftheirgelcontentandhardness,whichCanbeincreasedupto92.63%andO.72,respectively,anditWasfoundtha
7、ttheoptimalmassratioofaziridinederivativestocarboxylgroupsis5.84.Ontheotherhand,polycarbodiimidecanimprovetheadhesion,flexibilityandcoldcrack—resistanceofthecuredfilms,andtheoptimalmassratioofpolycarbodiimidetocarboxylgroupsis10.37.TheTGAcurvesofcuredfilmsshowthatt
8、heirthermalstabilitiesareincreasedbypolycarbodiimideanddecreasedbyaziridinederivatives.Keywords:aqueouspolyurethanedispersion;crosslinked;aziridi