| Veget abl e oil s such as tung-oil,lins eed oil and ot her dr y ing oil sconta ini ng unsa tur ate d fat ty acid,can form a tough film in ai r byoxidat i on , so it could be use d as a raw mat eri al of the wat erpr oof coat i ng,whi ch haslot s of advanta ges．such aslow cost,envir onment al fri endl y,ri ch of source, excell ent wat erpr oof pe rfo rmanc e,low vol at il e or ganiccompounds (VOC ) emi ssions,and so on．But ther e are als o di sa dvanta ges:pure veget able oil dri es very slowl y in the air．Whe n it was used in in doorareas,it rel ease d a smell whic h could not be accept ed by hum an being．The enginee ri ng appli cat ion s wer e seri ousl ylim it ed by thes e weaknes ses．In thi s proj ect,penta eryt hri t ol and va ri ous dr yer s were used to modif y theveget able oils,lins eed oil and tung oil were als o mixe d to impr ove thefilm appe arance . Though these met hods,a ki nd of wat erpr oof coati ng ofexcellent compre hensi ve per for mance was made . Bas ed on the ba sicproper ti es of the modi fied oil,optical mic rosc ope camer a,Four i erinf rar ed,stati c and dynam ic rheolog ical measur eme nts and model fi tt ing,the resul ts sh ow that the smell of the oil modif i ed by pent aer yth ri tol wasimpr oved obviously , the more the pent aer ythr it ol addi t ive s, the smalle rthe smell was,but dry ing time ri sed and water resi st an ce weakene d．Consi der ing the compre hensi ve proper ti es,8% of the dr ying oil is theopti mum addit i on of pe nta eryt hri tol . The cobal t napthe nate,the rar eeart h me tal naphthe n at e,the manganes e naphthe n ate,the mi xt ure ofmanganes e na phthen ate and zi r conium napht henat e,zinc naphthe nate ,2-et hylhe xanoat e cobalt,2- et hylhe xanoat e manganes e 2-et hylhe xanoat ezir coni um and 2-et hylhe xanoat e vanadi um and PbO dr ier s wer e us ed tomodif y the oil for an impr ove of the dr yi ng speed．In or der to get a bet t erfilm,the mixt ure of 2-et hylhe xanoat e cobalt and PbO wer e used,the bestform ula was:tung- oil 10 g+ 2-et hylhe xanoat e cobal t 0. 3 g + PbO 0. 2 g．St at ic rheol ogic al tes ts showed that all the modif i ed oil wer e she arthi nning fluid,the visc osi ty decrea se d wi th the increa si ng of shear rat e,the rel ati onsh ip bet we en visc osi ty and shear rate may be fit t ed wi th theC ross model．Vi scosi t y de crea sed wi th the incr eas ing tempe rat ure and canbefitted wit h Arr heni us form ula．Dynami c rheol ogical tes t showed that G'of the penta eryt hri t ol modif i ed oil dec reas e d wit h the incr easi ng ofω,and the tr end of G'' toωof the mo dif ied oil was changed by the modi fi er．Whe n temper at ure ri sed,G' and G'' decrea se d．The modulus val ue of dryermodif i ed oi l incr ease d fi rst ly wit hωincr ease d,then decrea se d．T herel at ions hip betw een vi sc oelas ti c modul us and the angula r freque ncycould be fi tt ed wit h a polynom ial．The change of m odul us wit htem perat ur e depend ed on the addi t i on of modi f ier s．... |
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