Kodi HEC imakhudzidwa ndi pH?

Hydroxyethylcellulose (HEC) ndi polima wosungunuka m'madzi womwe umagwiritsidwa ntchito m'makampani ndi kafukufuku wasayansi. Amagwiritsidwa ntchito makamaka ngati thickener, film-forming agent, adhesive, emulsifier and stabilizer.

Zinthu zoyambira za HEC
HEC ndi polima yosungunuka m'madzi yopanda ionic, yochokera ku hydroxyethylated yomwe imachokera ku cellulose kudzera mu ethylation reaction. Chifukwa cha chikhalidwe chake chosakhala cha ionic, khalidwe la HEC mu yankho nthawi zambiri silimasinthidwa kwambiri ndi pH ya yankho. Mosiyana ndi izi, ma polima ambiri a ionic (monga sodium polyacrylate kapena carbomers) amakhudzidwa kwambiri ndi pH chifukwa kuchuluka kwawo kumasintha ndikusintha kwa pH, zomwe zimakhudza kusungunuka kwawo komanso kukhuthala kwawo. ntchito ndi zina.

Kuchita kwa HEC pamitundu yosiyanasiyana ya pH
HEC nthawi zambiri imakhala yokhazikika pansi pa acidic ndi zamchere. Mwachindunji, HEC imatha kusunga kukhuthala kwake ndi kukhuthala kwake pamitundu yosiyanasiyana ya pH. Kafukufuku amasonyeza kuti kukhuthala ndi kuwonjezereka kwa mphamvu ya HEC kumakhala kokhazikika mkati mwa pH ya 3 mpaka 12. Izi zimapangitsa HEC kukhala yowonjezereka kwambiri komanso yokhazikika m'mafakitale ambiri ndipo ingagwiritsidwe ntchito pansi pa pH zosiyana.

Komabe, kukhazikika kwa HEC kungakhudzidwe pazambiri za pH (monga pH pansi pa 2 kapena pamwamba pa 13). Pansi pazimenezi, maunyolo a ma molekyulu a HEC amatha kukhala ndi hydrolysis kapena kuwonongeka, zomwe zimapangitsa kuchepetsa kukhuthala kwake kapena kusintha kwa zinthu zake. Choncho, kugwiritsa ntchito HEC pansi pazifukwa zoopsazi kumafuna chidwi chapadera kukhazikika kwake.

Malingaliro ofunsira
Muzochita zothandiza, kukhudzidwa kwa pH kwa HEC kumagwirizananso ndi zinthu zina, monga kutentha, mphamvu ya ionic, ndi polarity ya zosungunulira. M'mapulogalamu ena, ngakhale kusintha kwa pH kumakhala ndi zotsatira zochepa pa HEC, zinthu zina zachilengedwe zimatha kukulitsa izi. Mwachitsanzo, pansi pa kutentha kwakukulu, maunyolo a ma molekyulu a HEC amatha hydrolyze mofulumira, motero amakhudza kwambiri ntchito yake.

Kuonjezera apo, muzinthu zina, monga emulsions, gels ndi zokutira, HEC nthawi zambiri amagwiritsidwa ntchito pamodzi ndi zinthu zina (monga surfactants, salt kapena acid-base regulators). Panthawiyi, ngakhale HEC sichikhudzidwa ndi pH yokha, zigawo zina izi zingakhudze mwachindunji ntchito ya HEC mwa kusintha pH. Mwachitsanzo, kuchuluka kwa ma surfactants ena kumasintha pamitundu yosiyanasiyana ya pH, zomwe zingakhudze kuyanjana pakati pa HEC ndi ma surfactants, potero kusintha mawonekedwe a rheological a yankho.

HEC ndi polima yopanda ionic yomwe imakhala yosakhudzidwa ndi pH ndipo imakhala ndi ntchito yabwino komanso yosasunthika pamitundu yambiri ya pH. Izi zimapangitsa kuti zizigwiritsidwa ntchito kwambiri m'mapulogalamu ambiri, makamaka pomwe magwiridwe antchito okhazikika amafuta ndi opanga mafilimu amafunikira. Komabe, ndikofunikabe kulingalira momwe kukhazikika ndi ntchito za HEC zingakhudzidwe pansi pa zovuta za pH kapena zikagwiritsidwa ntchito ndi zinthu zina za pH-sensitive. Pazinthu zokhudzidwa ndi pH pamagwiritsidwe apadera, tikulimbikitsidwa kuti tiyese kuyesa ndi kutsimikizira kofananira musanagwiritse ntchito kwenikweni kuti muwonetsetse kuti HEC ikhoza kuchita bwino pansi pazimene zikuyembekezeka.