Ngabe i-hydroxyethyl cellulose isebenza kanjani njenge-thickener?

I-Cellulose iyi-polysaccharide eyenza izinhlobonhlobo zama-ether ancibilikayo emanzini. Ama-cellulose thickeners angama-polymers angenakuncibilika emanzini. Umlando wokusetshenziswa kwawo mude kakhulu, iminyaka engaphezu kwengu-30, futhi kunezinhlobonhlobo eziningi. Zisasetshenziswa cishe kuwo wonke amapende e-latex futhi yizona ezihamba phambili zokuqina. Ama-cellullosic thickeners asebenza kahle kakhulu ezinhlelweni ezinamanzi ngoba ashubisa amanzi ngokwawo. Embonini kapende, i-cellulose thickeners esetshenziswa kakhulu yile: i-methyl cellulose (MC), i-hydroxyethyl cellulose (HEC), i-ethyl hydroxyethyl cellulose (EHEC), i-hydroxypropyl cellulose (HPC), i-hydroxypropyl methyl cellulose (HPMC) kanye ne-hydrophobically modified hydroxyethyl cellulose ( HMHEC). I-HEC iyi-polysaccharide encibilika emanzini esetshenziswa kakhulu ekushubeni kopende be-latex be-matt kanye ne-semi-gloss yezakhiwo ze-latex. Ama-thickeners ayatholakala ngamamaki e-viscosity ahlukene futhi ama-thickeners anale cellulose anokuhambisana okuhle kombala kanye nokuzinza kwesitoreji.

Ileveli, i-anti-splash, ifilimu-forming kanye nezakhiwo zokunqanda ukugoqa zefilimu enamathelayo incike esisindweni samangqamuzana e-HEC. I-HEC namanye ama-polymers angancibiliki emanzini angahlobene ajiya isigaba samanzi sokumboza. Ama-cellulose thickeners angasetshenziswa yedwa noma ahlanganiswe namanye ama-thickeners ukuze athole i-rheology ekhethekile. Ama-cellulose ether angaba nezisindo ezihlukene zamangqamuzana ahlukene kanye namamaki e-viscosity ahlukene, asukela esisindweni esiphansi samangqamuzana angu-2% esisombululo samanzi esine-viscosity engaba ngu-10 MPS kuya ku-viscosity yesisindo se-molecular ephakeme engu-100 000 MP.S. Amabanga aphansi esisindo samangqamuzana ngokuvamile asetshenziswa njengama-colloid avikelayo ku-latex paint emulsion polymerization, futhi amamaki avamile (viscosity 4 800–50 000 MP·S) asetshenziswa njengama-thickeners. Indlela yalolu hlobo lwe-thickener ingenxa ye-hydration ephezulu yamabhondi e-hydrogen kanye nokugoqa phakathi kwamaketanga ayo amangqamuzana.

I-cellulose yomdabu iyi-polymer enesisindo samangqamuzana aphezulu ajiya kakhulu ngokubopha phakathi kwamaketanga amangqamuzana. Ngenxa ye-viscosity ephezulu ngenani eliphansi le-shear, indawo yokulinganisa impofu, futhi ithinta ukucwebezela kwefilimu yokugqoka. Ngezinga eliphezulu le-shear, i-viscosity iphansi, ukumelana ne-splash yefilimu yokugqoka impofu, futhi ukugcwala kwefilimu yokugqoka akukuhle. Izici zohlelo lokusebenza lwe-HEC, njengokumelana nebhulashi, ukuqoshwa kwefilimu kanye ne-roller spatter, zihlobene ngokuqondile nokukhetha kokuqina. Futhi izakhiwo zayo zokugeleza ezifana nokulinganisa kanye nokumelana ne-sag kuthinteka kakhulu ama-thickeners.

I-Hydrophobically modified cellulose (HMHEC) iyi-cellulose thickener enokuguqulwa kwe-hydrophobic kwamanye amaketanga anamagatsha (amaqembu amaningana e-alkyl yamaketanga amade ethulwa eduze kweketango eliyinhloko lesakhiwo). Lokhu kunamathela kune-viscosity ephezulu kumazinga aphezulu we-shear ngakho-ke ukwakheka kwefilimu okungcono. Okufana neNatrosol Plus Grade 330, 331, Cellosize SG-100, Bermocoll EHM-100. Ukuqina kwawo kuqhathaniswa nokuqina kwe-cellulose ether enesisindo samangqamuzana esihlobene kakhulu. Ithuthukisa i-viscosity kanye nokulingana kwe-ICI, futhi yehlisa ukungezwani kwendawo. Isibonelo, ukungezwani okungaphezulu kwe-HEC cishe ku-67 MN/m, futhi ukungezwani kwendawo ye-HMHEC kungu-55~65 MN/m.

I-HMHEC ine-sprayability enhle kakhulu, i-anti-sagging, izakhiwo zokulinganisa, i-gloss enhle kanye ne-anti-pigment caking. Isetshenziswa kabanzi futhi ayinawo umthelela omubi ekwakhiweni kwefilimu yamapende amahle wezinhlayiyana ze-latex. Ukusebenza okuhle kokwenza ifilimu kanye nokusebenza kwe-anti-corrosion. Le thickener ethile ehlanganisayo isebenza kangcono ngezinhlelo ze-vinyl acetate copolymer, futhi ukusebenza kwayo kufana nezinye izingqimba ezihlangene, kodwa ezinokwakheka okulula.


Isikhathi sokuthumela: Mar-16-2023