Effect of Formulation Parameters on Adhesive …

1 Effect of FormulationParameterson AdhesivePropertiesof TileAdhesiveMortars imsaCement ResearchandApplication CenterAugust, 2017 Thefactorsaffectinginterfacialresistance betweentilesandpolymermodifiedcementmort arsare: Ceramictilewaterabsorption, Cementamountandcomposition, Theamountandtypeofpolymer, Installationprocedures, Theyaregenerallyvinylacetate-based(VA)wi thpolyvinylalcohol(PVA)thatisspreydriyin gagent. ;suchasconcrete,sceramic,wood,vitrifiedg lassbytheirhydroxylgroupsontheirsidechai ns. Bothpolyvinylalcoholandvinylacetate-base d(VA) ,theyarecopolymerizedwithhydrophobicpoly merusuallywithethyleneorvinylversatate(V eoVa).

2 Latex PolymersEffect of Chemistryof theRedispersibleLatexPowder(RDP) in Use ToinvestigateeffectofchemistryoftheRDP,t hesameamount(2wt%)VA/VeovaorEVA-basedred ispersiblepowder(RDF)wereused. Nosaggingwasobservedonbothmortarsprepare dwithVA/VeovaorEVA-basedRDF. Themeasuredviscositieswereof76,000and70, 000mPas,indicatingthatworkabilitydoesnot changewithdifferenttypesofpolymericpowde redresin. ThemortarformedwithVA/VeoVAperformedextr emelywellat20minandbondstrengththreetime shigherthantheminimalrequirementof75psi( )becauseofhydrophobicsidechainoftheVeoVA copolymer. Afterparticlecoalescenceandfilmformation ,waterevaporationduringthe28daysdecrease sandprovidesbetterhydrationofcementatear lyage,promotingmechanicalanchoringoftheC -S-Hgelfromcement' of Chemistryof theRedispersibleLatexPowder(RDP) in UseEffect of Chemistryof theRedispersibleLatexPowder(RDP) in Use Thepolymer ,delayedfilmformationuponC-S-Hgelwiththe VA/Veovacopolymerco-matrixformationatane arlyage(1day)isobserved.

3 Asseenfigure2,EVAbasedmortarsexhibitshig herinitialshearstress(1day) of Chemistryof theRedispersibleLatexPowder(RDP) in UseEffect of Chemistryof theRedispersibleLatexPowder(RDP) in Use Weff:massofefficientwater Nosaggingwasobserved,andthemeasuredvisco sitieswere76,000and100, , of CementDosageat ConstantWeff/C Ratio In mix 2, The increase in viscosity with decreasing cement can be becauseof additionof starchether. Hydrocolloidsrate increasesfrommix 1( wt%) tomix 2 ( %) Duetothehigh hydrocolloidsrate in mix 2, opentime performanceis betterthanmix 1 Effect of CementDosageat ConstantWeff/C Ratio Highershearstressvalueswereobtainedonthe mixdesign1duetohighercementcontentatearl yages(upto7days,independentlyofthecuring conditions).

4 At28days,shearstressvaluesoftwomortarsex hibitssimilarintermsofco-matrixdevelopme ntbothmortars of CementDosageat ConstantWeff/C RatioEffect of CementDosageat ConstantWeff/C RatioEffect of the CelluloseEtherContent Mortarsviscositiesmeasuredas38,000,50,00 0and54, , , Ifhydrocolloidsamountislow, ,enoughwaterforhydrationcannotbeprovided becauseofevaporationwhichresultsdecrease inbondvalues. Ifhydrocolloidsamountishigh, of the CelluloseEtherContent Maximumopentimeperformanceisobservedonam ortarproportionedwithoptimumhydrocolloid srate( ). Effect of the CelluloseEtherContent Whenthehydrocolloidsrateislow,afullconta ctbetweenthemortarandthetiletakesplace,l eadingtobettershearstressvalueswithatear lyages(1day).

5 After7days,thereisnotenoughwaterretainin gadmixtureinthemixturetoreleaseenoughwat erinordertopermitgoodhydration,resulting inlowshearstressvalueswhenmortariscurede itheratroomtemperatureorat70 of the CelluloseEtherContent Whenthehydrocolloidsrateishigh,1dayshear stressvalueislowbyretardingthehydrationo fcement(waterentrapment), of the CelluloseEtherContentAnoptimumdosageofhy drocolloidsshouldbefoundtobalancethesetw oeffects, of the CelluloseEtherContentEffect of the RDP Content ViscositiesdecreasedwithincreaseofRDPval uefrom2to3(wt%)duetoplasticizingeffectof RDPinfreshmortar.

6 AlsoduetowaterretentionefffectofRDP,thew ettingabilitywasslightlyenhancewithincre aseinwt%ofRDP.(%70ofcovarageembeddedinth eCTA30min). Allofthematerials(RDP,starchetherandcell uloseether) IncreaseinRDPcontentcausesdecreaseinopen timeperformanceasseenfigure10. of the RDP ContentEffect of the RDP Content Ingeneral;thehigherpolymertocementratio, thebetterbondstrength. Maximumpolymertocementratioisbetween5%an d10%irrespectivetothepolymertype. , , , , of the RDP Content Thechemistryoftheredispersiblepowderinus ewillaffectonlyshearstressvaluesatearlya geswhensamplesaredrycured.

7 VA/VeoVAbasedRDPsenhancethewetshearstres sofcementitioustileadhesivesduetotheirlo ng -alkylsidechain. , , , ,Effectofformulationparametersonadhesive propertiesofANSI118-15and118-11compliant tileadhesivemortars,InternationalJournal ofAdhesion& Adhesive ,66(2016)73 Mah. Tekke Yenita kent-MERS N T RK YET: +90 324 241 23 37C: +90 531 373 97 70F: +90 324 454 00 52 e-mail : and Application Center