Isebenza njani i-HPMC coating dispersant?

1. Intshayelelo

IHydroxypropyl Methylcellulose (HPMC) yipolymer enyibilikayo emanzini esetyenziswa kakhulu kwiingubo, izinto zokwakha, amayeza kunye nezinye iindawo. Kwishishini lokugquma, i-HPMC ayisetyenziswanga nje ngokuba sisityebi, isizinzisi kunye nefilimu yangaphambili, kodwa nanjengesasazi esisebenza kakuhle kakhulu. Imisebenzi yayo ephambili kwiingubo ibandakanya ukuphucula ukuzinza kweengubo, ukuphucula i-rheology, ukuphucula ukusebenza kokwakhiwa kunye nomgangatho wengubo yokugqibela.

2. Iimpawu zesakhiwo se-HPMC

Ulwakhiwo lwemolekyuli ye-HPMC iqulethe i-cellulose skeleton kunye ne-hydroxypropyl kunye ne-methyl substituents. Ubume bayo obukhethekileyo bunika ukunyibilika kwe-HPMC emanzini kunye nokukwazi ukwenza isisombululo se-viscoelastic kwisisombululo samanzi. I-HPMC isebenzisana neemolekyuli zokunyibilikisa ngokusebenzisa i-hydrogen bonding kunye ne-van der Waals amandla, ngaloo ndlela inyibilika emanzini kwaye yenze inkqubo ezinzileyo yokusasazwa.

Ubunzima bemolekyuli kunye neqondo lokutshintshela (DS) ye-HPMC ichaphazela ukunyibilika kwayo kunye ne-viscosity. Ngokubanzi, ubunzima bemolekyuli ephezulu kunye nenqanaba lokutshintsha linyusa i-viscosity kunye nexesha lokuchithwa kwe-HPMC. Ezi mpawu zibalulekile kumsebenzi we-HPMC njenge-dispersant yokwambathisa.

3. Indima ye-HPMC kwiingubo

3.1 Ukuphucula i-pigment dispersibility

I-HPMC isetyenziswa ikakhulu ekuphuculeni i-dispersibility of pigments kwi-coatings. Kwinkqubo yokuveliswa kweengubo, i-agglomeration ye-pigment particles yingxaki eqhelekileyo, ekhokelela kwiingubo ezingalinganiyo nezingazinzanga, ezichaphazela i-gloss kunye nombala ofanayo wengubo. Abasasazi be-HPMC badlala indima kule miba ilandelayo:

I-Electrostatic repulsion: Isisombululo esenziwe yi-HPMC enyibilikayo emanzini sinomsebenzi ophezulu ophezulu kwaye sinokubhengezwa kumphezulu wamasuntswana e-pigment ukuze ahlawule. Le repulsion electrostatic ukwahlula amasuntswana pigment omnye komnye kwaye kunciphisa agglomeration.

Impembelelo yokuthintela i-steric: I-polymer chain ye-HPMC inokwenza umaleko okhuselayo kumphezulu wamasuntswana e-pigment, yandise umgama wendawo phakathi kwamasuntswana, kwaye ngaloo ndlela ithintele umtsalane kunye nokudibanisa phakathi kwamasuntswana.

Isiphumo sokuzinzisa: I-HPMC idibanisa kunye neamolekyu zamanzi ngokusebenzisa iibhondi ze-hydrogen ukwenza inkqubo yesisombululo esizinzile, ukuthintela amaqhekeza e-pigment ekuhlaliseni kwinkqubo, kunye nokuphucula ukuzinza kwengubo.

3.2 Ukuphucula irheology

Omnye umsebenzi obalulekileyo we-HPMC kukuphucula i-rheology yeengubo, oko kukuthi, ukuhamba kunye neempawu zokuguqulwa kweengubo. Iimpawu ezintle ze-rheological zokugqoka zinceda ukuba zibe nokusasazeka kakuhle kunye nokulinganisa ngexesha lokwakha, ukwenza ifilimu yokugqoka efanayo. I-HPMC ichaphazela iipropathi zerheological zokwaleka ngezi ndlela zilandelayo:

Ukwandiswa kwe-Viscoelasticity: I-polymer chain network structure eyenziwe yi-HPMC emanzini inika isisombululo i-viscoelasticity ethile. Le viscoelasticity inokulungelelanisa ukuziphatha kokuhamba kwengubo, ukwenzela ukuba ibe ne-viscosity efanelekileyo xa uxubha, ukunciphisa ukugoba kunye nokuvuza.

Ukucheba ukucheba: Izisombululo ze-HPMC zihlala zibonisa iipropati zokucheba, oko kukuthi, zine-viscosity ephezulu kumazinga aphantsi okucheba kunye ne-viscosity esezantsi kumazinga aphezulu okucheba. Le propati yenza i-coating ibe nokuzinza okungcono kwimeko engatshintshiyo kwaye kulula ukusasazeka ngexesha lokwakha.

Thixotropy: Ezinye izisombululo ze-HPMC zikwabonisa i-thixotropy, oko kukuthi, i-viscosity ibuyiselwa ekuphumleni, ebaluleke kakhulu ekunciphiseni ukugoba kunye nokuhla kwengubo.

3.3 Ukuphucula ukusebenza kokugquma

I-HPMC ayinayo kuphela impembelelo ebalulekileyo ekusebenzeni kwengubo ngexesha lokwakha, kodwa iphucula kakhulu umgangatho wengubo yokugqibela. I-HPMC iphucula ukusebenza kweengubo kule miba ilandelayo:

Ukwaleka flatness: HPMC iphucula rheology yokwaleka, iphucula ukusasazeka kunye nomgangatho wokwaleka, kwaye yenza isambatho igudileyo kwaye iyunifomu ngakumbi.

Ukumelana namanzi kunye nokumelana nemozulu: I-HPMC yenza isakhiwo sothungelwano esixineneyo kwi-coating, eyandisa ukuxhathisa kwamanzi kunye nokukwazi ukuguga kwengubo, kwaye iphucula ukuxhathisa kwemozulu yengubo.

Ukubambelela: I-HPMC iphucula ukunamathela kwengubo, ukwenzela ukuba i-coating ikwazi ukunamathela ngokuqinileyo kumphezulu we-substrate, kwaye iphucula ukuqina kwengubo.

4. Imizekelo yokusetyenziswa kwe-HPMC

4.1 Iingubo zezakhiwo

Kwiingubo zokwakha, i-HPMC isetyenziselwa ukuphucula ukusasazeka kwemibala kunye ne-rheology yeengubo, ngakumbi kwiingubo ezisekelwe emanzini. I-HPMC iphucula uzinzo kunye nokusebenza kokwakhiwa kwengubo, ukwenzela ukuba i-coating ibe nenqanaba elingcono kunye nokunamathela eludongeni, kwaye ithintele ifilimu ukuba ingabikho kwaye ingalingani.

4.2 Iingubo zamashishini

I-HPMC ikwasetyenziswa ngokubanzi kwiingubo zamashishini. Ayiphuculi kuphela i-dispersibility ye-pigments, kodwa iphucula ukusebenza kokwakhiwa kweengubo, okwenza ifilimu yokugquma ibambelele ngakumbi kwisinyithi, iplastiki kunye nezinye ii-substrates, kunye nefilimu yokwaleka eyenziwe yomelele ngakumbi.

4.3 Ezinye iingubo zokwaleka

I-HPMC iphinda isetyenziswe kwiingubo ezikhethekileyo ezahlukeneyo, ezifana neengubo zokuvala umlilo, i-anti-corrosion coatings, njl njl. iimeko ezahlukeneyo ezinzima.

Njenge-dispersant yokwambathisa, i-HPMC idlala indima ebalulekileyo ekuphuculeni i-dispersibility ye-pigments, ukuphucula i-rheology ye-coatings kunye nokuphucula ukusebenza kweefilimu zokugquma. Ubume bayo obukhethekileyo kunye nomsebenzi unika uluhlu olubanzi lwamathemba okusebenza kwishishini lokugquma. Ngokuphuhliswa kobugcisa bokugquma, ukusetyenziswa kwe-HPMC kuya kuqhubeka nokwandisa, ukubonelela ngamathuba amaninzi okuphucula kunye nokuqaliswa kokusebenza kokugquma.