Hydroxyethyl cellulose (HEC) isiri-ionic, mvura-inonyungudika polima inotorwa kubva muselulosi kuburikidza nekugadzirisa kemikari. Inowana kushandiswa kwakakura mumaindasitiri akasiyana nekuda kwezvakasiyana zvimiro, sekukora, kudzikamisa, uye kugona kugadzira mafirimu. Mukushandisa uko pH kugadzikana kwakakosha, kunzwisisa maitiro eHEC pasi pemamiriro akasiyana epH kwakakosha.
Iyo pH kugadzikana kweHEC inoreva kugona kwayo kuchengetedza kuvimbika kwayo kwechimiro, rheological zvimiro, uye kuita mukati mehuwandu hwepH nharaunda. Uku kugadzikana kwakakosha mumashandisirwo akadai sezvigadzirwa zvekuchengetedza munhu, mishonga, machira, uye zvekuvakisa, uko pH yenzvimbo yakatenderedza inogona kusiyana zvakanyanya.
Chimiro:
HEC inowanzogadzirwa nekuita cellulose ne ethylene oxide pasi pemamiriro ealkaline. Iyi nzira inoguma nekutsiviwa kwemapoka ehydroxyl emusana we cellulose ne hydroxyethyl (-OCH2CH2OH) mapoka. Iyo dhigirii yekutsiva (DS) inoratidza avhareji yenhamba yemapoka ehydroxyethyl pane anhydroglucose unit mucheni ye cellulose.
Properties:
Solubility: HEC inonyungudika mumvura uye inoumba yakajeka, viscous mhinduro.
Viscosity: Inoratidza pseudoplastic kana shear-kutetepa maitiro, zvichireva kuti viscosity yayo inodzikira pasi pekunetseka kweshear. Ichi chivakwa chinoita kuti chibatsire mumashandisirwo uko kuyerera kwakakosha, senge pendi uye machira.
Kukora: HEC inopa viscosity kune zvigadziriso, zvichiita kuti ive yakakosha seyakakora mumiriri mumhando dzakasiyana siyana.
Kugadzira firimu: Inogona kuumba anochinjika uye akajeka mafirimu kana akaomeswa, izvo zvinobatsira mukushandisa senge zvinonamira uye machira.
pH Kugadzikana kweHEC
Iyo pH kugadzikana kweHEC inopesvedzerwa nezvinhu zvakati wandei, zvinosanganisira chimiro chemakemikari yepolymer, kudyidzana nenzvimbo yakatenderedza, uye chero zvinowedzera zviripo mukuumbwa.
pH kugadzikana kweHEC mumhando dzakasiyana dzepH:
1. Asidhi pH:
Pane acidic pH, HEC inowanzogadzikana asi inogona kuita hydrolysis kwenguva yakareba pasi pemamiriro e acidic yakaoma. Nekudaro, mune akawanda anoshanda maapplication, senge ega zvigadzirwa zvekuchengeta uye machira, apo acidic pH inosangana, HEC inoramba yakagadzikana mukati meiyo yakajairika pH renji (pH 3 kusvika 6). Kupfuura pH 3, njodzi yehydrolysis inowedzera, zvichikonzera kudzikira zvishoma nezvishoma muviscosity uye kuita. Izvo zvakakosha kuti utarise iyo pH yemagadzirirwo ane HEC uye agadzirise iwo sezvinodiwa kuchengetedza kugadzikana.
2. Neutral pH:
HEC inoratidza kugadzikana kwakanyanya pasi pekusarerekera pH mamiriro (pH 6 kusvika 8). Iyi pH renji yakajairika mumashandisirwo mazhinji, anosanganisira zvizorwa, mishonga, uye zvigadzirwa zvemumba. HEC-ine maumbirwo anochengeta viscosity yavo, thickening zvivakwa, uye kuita kwese mukati meiyi pH renji. Nekudaro, zvinhu zvakaita setembiricha uye simba reionic zvinogona kukanganisa kugadzikana uye zvinofanirwa kutariswa panguva yekugadzira.
3. Alkaline pH:
HEC haina kugadzikana pasi pemamiriro e alkaline kana ichienzaniswa ne acidic kana kusarerekera pH. Pamusoro pepH mazinga (pamusoro pH 8), HEC inogona kuderedzwa, zvichiita kuti kuderera kwe viscosity uye kurasikirwa kwekuita. Alkaline hydrolysis ye ether linkages pakati pe cellulose musana uye hydroxyethyl mapoka anogona kuitika, zvichitungamira kune cheni scission uye kuderedzwa kwema molecular uremu. Naizvozvo, mukugadzirwa kwealkaline senge dhizaini kana zvinhu zvekuvaka, mamwe mapolymers kana stabilizer anogona kusarudzwa pane HEC.
Zvinhu Zvinokonzera pH Kugadzikana
Zvinhu zvinoverengeka zvinogona kukanganisa pH kugadzikana kweHEC:
Dhigirii reKutsiva (DS): HEC ine yakakwirira DS kukosha inoita kunge yakagadzikana zvakanyanya pahupamhi pH renji nekuda kwekuwedzera kutsiviwa kwemapoka ehydroxyl nemapoka ehydroxyethyl, ayo anovandudza kunyungudika kwemvura uye kuramba kuhydrolysis.
Tembiricha: Tembiricha yakakwira inogona kukurumidza kuita kemikari, kusanganisira hydrolysis. Nokudaro, kuchengetedza zvakakodzera kuchengetedza uye kupisa kwekushisa kwakakosha pakuchengetedza pH kugadzikana kweHEC-ine maitiro.
Ionic Strength: Yakanyanya kuwanda yemunyu kana mamwe maion mukugadzira inogona kukanganisa kugadzikana kweHEC nekukanganisa kunyungudika kwayo uye kudyidzana nemamorekuru emvura. Simba reIonic rinofanirwa kuvandudzwa kuti rideredze zvinokanganisa mhedzisiro.
Additives: Kubatanidzwa kwezvinowedzera zvakadai se surfactants, preservatives, kana buffering agents zvinogona kukanganisa pH kugadzikana kweHEC maumbirwo. Kuenderana kuyedzwa kunofanirwa kuitwa kuti ive nechokwadi chekuwedzera kuenderana uye kugadzikana.
Zvikumbiro uye Mafungiro eKugadzira
Kunzwisisa pH kugadzikana kweHEC kwakakosha kune vanogadzira mumaindasitiri akasiyana.
Heano mamwe maitiro-akanangana nekushandisa:
Personal Care Zvigadzirwa: Mune shampoos, maconditioners, uye lotions, kuchengetedza pH mukati meiyo yaidiwa renji (kazhinji yakatenderedza isina kwayakarerekera) inovimbisa kugadzikana uye kuita kweHEC seyakakora uye inomisa mumiriri.
Pharmaceuticals: HEC inoshandiswa mumuromo kumiswa, ophthalmic mhinduro, uye topical formulations. Magadzirirwo anofanirwa kugadzirwa uye kuchengetwa pasi pemamiriro anochengetedza HEC kugadzikana kuti ive nechokwadi chekubudirira kwechigadzirwa uye hupenyu hwesherufu.
Coatings uye Paints: HEC inoshandiswa se rheology modifier uye thickener mumvura-based pendi uye machira. MaFormulators anofanirwa kuyera pH zvinodiwa nemamwe maitiro ekuita senge viscosity, kuenzanisa, uye kuumbwa kwemafirimu.
Zvishandiso Zvekuvaka: Mune cementitious formulations, HEC inoshanda seyekuchengetedza mvura uye inovandudza kushanda. Zvisinei, mamiriro ealkaline mu simenti anogona kupikisa HEC kugadzikana, zvinoda kunyatsosarudzwa uye kugadzirisa kugadzirisa.
Hydroxyethyl cellulose (HEC) inopa yakakosha rheological uye inoshanda zvivakwa mune akasiyana maapplication. Kunzwisisa kugadzikana kwayo pH kwakakosha kune vanogadzira kuti vagadzire yakagadzikana uye inoshanda maumbirwo. Nepo HEC ichiratidza kugadzikana kwakanaka pasi pekusarerekera pH mamiriro, kufunga kunofanirwa kuitwa kune acidic uye alkaline nharaunda kudzivirira kushatisa uye kuve nechokwadi chekuita kwakakwana. Nekusarudza iyo yakakodzera HEC giredhi, optimizing ekugadzirisa maparameter, uye kushandisa akakodzera mamiriro ekuchengetera, vanogadzira vanogona kushandisa mabhenefiti eHEC munzvimbo dzakasiyana siyana dzepH.
Nguva yekutumira: Mar-29-2024