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1、碩士論文緩控釋化肥用膜材的制備及其性能研究摘要本論文探討了脲醛樹脂(UF)預(yù)聚物的改性合成問題,通過在脲醛預(yù)聚物合成過程中加入助劑P和填料M達(dá)到對(duì)脲醛預(yù)聚物進(jìn)行改性的目的。論文分別對(duì)處理前后的填料M進(jìn)行了沉降觀察、紅外、熱性能和XRD等表征分析,研究確定其參與反應(yīng)的情況;同時(shí),比較研究了填料M添加量對(duì)改性脲醛樹脂預(yù)聚物粘度、剪切強(qiáng)度和熱性能的影響,并用SEM對(duì)改性脲醛樹脂的脆斷面進(jìn)行了觀察。此外,還制備了不同組成和不同厚度的各種改性脲醛樹脂膜,研究了不同改性脲醛膜材和不同厚度的脲醛膜材對(duì)尿素的透過性能。脲
2、醛樹脂作為包膜材料具有成本低、含氮量高等優(yōu)勢(shì),并且其本身就是緩釋氮肥。本文采用在脲醛預(yù)聚物合成中分別加入助劑P和填料M來對(duì)其進(jìn)行化學(xué)改性,并對(duì)改性結(jié)果進(jìn)行了研究分析。結(jié)果表明,改性后脲醛預(yù)聚物的粘度和剪切強(qiáng)度,較未改性前均有明顯提升,且隨著填料M添加量的增加而增大,其熱分解溫度也因填料M的加入而往高溫方向推移;同時(shí),SEM觀察表明,填料在樹脂中分散較均勻,沒有明顯團(tuán)聚,說明填料的分散性比較好。改性脲醛膜材透肥性能的研究結(jié)果表明,膜的累積透肥量隨著改性脲醛膜材厚度的增加而降低;膜厚相同時(shí),同時(shí)加助劑P和填料
3、M的改性脲醛膜比僅加助劑P改性的脲醛膜對(duì)尿素的累積透過量更大;在膜厚和助劑P添加量相同時(shí),改性脲醛膜對(duì)尿素的累積透過量隨填料M添加量的增加而增大。關(guān)鍵詞:脲醛樹脂,化學(xué)改性,表征分析,改性脲醛膜AbstractThemodifiedsyntheticoftheurea-formaldehyde(UF)resinprepolymerwasexplored.Forthepurposeofmodification,weaddedtheauxiliaryofPandfillerofMtothesystemwhen
4、meUFprepolymerWassynthesized.Inordertogiveresearchontheirparticipationinthecaseofreaction,thetreatedanduntreatedfillerofMwerecharacterized,respectively,suchasSedimentationtest,F(xiàn)TIR,TGA,DTAandXRD.Atthesametime.westudiedtheinfluenceoftheamountoffillerMadded
5、ontheUFprepolyrnersviscosity,shearstrengthandthermalproperties.Besidethese,wealsoUSeSEMtostudythecross.sectionofUFresin.Inaddition,thedifferentcomponentsanddifferentthicknessofthevariousmodifiedUFresinmembranewerepreparedtostudyitsabilityinhamperofurea.As
6、t11ecoatingmaterials,UFresinhasmanyadvantages,suchaslow-costandhighnitrogencontents,andit’Sslow-releasenitrogenfertilizerinitself.Inthepaper,weaddedtheauxiliaryofPandfillerofMtothesystem,andstudiedtheresultsofthemodification.Theresultsshowthattheviscosity
7、andshearstrengthofthemodifiedUFprepolymerhavebeensignificantlyenhanced,and謝ththeincreasingamountofM,thethermaldecompositionofUFresinmovedtoahighertemperature.Atthesametime,theSEMobservationshowsthat晰ththevolumeoffillerincreasing,fillerdistributedmoreeveni
8、ntheresinandhadnoreunion.Theseshowthatthedispersionoffillerisbetter.Inthepaper,ourstudyshowsthattheamountofureathroughthemembraneWasreduced、)l,iththeincreaseofthemembrane’Sthickness.Withthesamethickness.theUFmembran