I-Cellulose yi-polysaccharide eyenza iintlobo ngeentlobo zee-ethers ezinyibilikayo emanzini. Ii-cellulose thickeners zii-polymers ezinyibilikayo emanzini ezingezizo i-ionic. Imbali yokusetyenziswa kwayo inde kakhulu, ingaphezulu kweminyaka engama-30, kwaye kukho iintlobo ezininzi. Zisasetyenziswa phantse kuzo zonke iipeyinti ze-latex kwaye zezona ziphambili kwii-thickeners. Ii-thickeners ze-cellulose zisebenza kakhulu kwiinkqubo zamanzi kuba zijiyisa amanzi ngokwazo. Kwishishini lokupenda, ii-thickeners ze-cellulose ezisetyenziswa kakhulu zezi: i-methyl cellulose (MC), i-hydroxyethyl cellulose (HEC), i-ethyl hydroxyethyl cellulose (EHEC), i-hydroxypropyl cellulose (HPC), i-hydroxypropyl methyl cellulose (HPMC) kunye ne-hydroxyethyl cellulose eguqulweyo ngamanzi (HMHEC). I-HEC yi-polysaccharide enyibilikayo emanzini esetyenziswa kakhulu ekujiyiseni iipeyinti ze-latex ezakhiweyo ze-matt kunye ne-semi-gloss. Ii-thickeners ziyafumaneka kwiindidi ezahlukeneyo ze-viscosity kwaye ii-thickeners ezinale cellulose zinokuhambelana okuhle kombala kunye nozinzo lokugcina.
Iipropati zokulinganisa, zokulwa nokuqhekeka, ukwenza ifilimu kunye nokungagungqi kwefilimu yokugquma zixhomekeke kubunzima beemolekyuli ze-HEC. I-HEC kunye nezinye iipolymers ezinyibilikayo emanzini ezingadibaniyo ziqinisa isigaba samanzi sokugquma. Izithambisi ze-cellulose zingasetyenziswa zodwa okanye zidityaniswe nezinye izithambisi ukuze kufunyanwe i-rheology ekhethekileyo. Ii-ether ze-cellulose zinokuba nobunzima beemolekyuli ezahlukeneyo kunye namanqanaba ahlukeneyo e-viscosity, ukusuka kwisisombululo samanzi esiphantsi se-molecule esingu-2% esine-viscosity emalunga ne-10 MPS ukuya kwi-viscosity ephezulu ye-molecular weight ye-100 000 MP.S. Amanqanaba aphantsi obunzima beemolekyuli adla ngokusetyenziswa njengee-colloids ezikhuselayo kwi-polymerization ye-latex paint emulsion, kwaye amanqanaba aqhelekileyo (i-viscosity 4 800–50 000 MP·S) asetyenziswa njenge-visors. Indlela olu hlobo lwe-thickener lubangelwa kukufunxwa okuphezulu kweebhondi ze-hydrogen kunye nokuxinana phakathi kwee-chain zayo zeemolekyuli.
I-cellulose yendabuko yi-polymer enobunzima obukhulu beemolekyuli eqina kakhulu ngokuxinana phakathi kwee-molecular chains. Ngenxa ye-viscosity ephezulu kwi-low shear rate, i-leveling property ayilunganga, kwaye ichaphazela ukukhanya kwefilimu yokugquma. Kwi-high shear rate, i-viscosity iphantsi, i-splash resistance yefilimu yokugquma ayilunganga, kwaye ukugcwala kwefilimu yokugquma ayilunganga. Iimpawu zokusetyenziswa kwe-HEC, ezinje ngokuxhathisa ibrashi, ukufota kunye ne-roller spatter, zinxulumene ngokuthe ngqo nokukhetha i-thickener. Kwakhona iipropati zayo zokuhamba ezifana nokuxhathisa i-leveling kunye ne-sag zichaphazeleka kakhulu zi-thickeners.
I-Hydrophobically modified cellulose (HMHEC) yi-cellulose thickener enotshintsho lwe-hydrophobic kwiityathanga ezithile ezinamasebe (amaqela amaninzi e-alkyl eentyathanga ezinde angeniswa kwityathanga eliphambili lesakhiwo). Olu phawu lune-viscosity ephezulu ngamanani aphezulu okucheba kwaye ngenxa yoko ukwakheka kwefilimu kungcono. Ezifana neNatrosol Plus Grade 330, 331, Cellosize SG-100, Bermocoll EHM-100. Isiphumo sayo sokutyeba sifana nese-cellulose ether thickeners ezinobunzima obukhulu kakhulu be-molecular. Iphucula i-viscosity kunye ne-leveling ye-ICI, kwaye inciphisa uxinzelelo lomphezulu. Umzekelo, uxinzelelo lomphezulu lwe-HEC lumalunga ne-67 MN/m, kwaye uxinzelelo lomphezulu lwe-HMHEC luyi-55~65 MN/m.
I-HMHEC inamandla okutshiza kakuhle, ayityibiliki, ineempawu zokulenza ilingane, icwebezela kakuhle kwaye ayifuni mbala. Isetyenziswa kakhulu kwaye ayinampembelelo imbi ekudalweni kwefilimu yepeyinti yelatex enobukhulu obuncinci. Isebenza kakuhle ekwenzeni ifilimu kwaye ayisebenzisi mbala. Le associative thickener isebenza ngcono kwiinkqubo ze-vinyl acetate copolymer, kwaye ukusebenza kwayo kufana nezinye i-associative thickeners, kodwa ineefomyula ezilula.
Ixesha lokuthumela: Matshi-16-2023