Focus on Cellulose ethers

HEC ọ na-enwe mmetụta maka pH?

Hydroxyethylcellulose (HEC) bụ polymer soluble mmiri nke a na-ejikarị na ụlọ ọrụ na nyocha sayensị. A na-ejikarị ya eme ihe dị ka onye na-eku ume, onye na-emepụta ihe nkiri, nrapado, emulsifier na stabilizer.

Njirimara ndị bụ isi nke HEC
HEC bụ polymer na-abụghị ionic mmiri soluble, ihe na-emepụta hydroxyethylated sitere na cellulose site na mmeghachi omume ethylation. N'ihi ọdịdị ya na-abụghị nke ionic, omume nke HEC na ngwọta adịghị agbanwe agbanwe site na pH nke ngwọta. N'ụzọ dị iche, ọtụtụ polymers ionic (dị ka sodium polyacrylate ma ọ bụ carbomers) na-enwe mmetụta nke ọma na pH n'ihi na ụgwọ ha na-agbanwe na mgbanwe na pH, na-emetụta ha solubility na ndim. arụmọrụ na ihe ndị ọzọ.

Ịrụ ọrụ nke HEC na ụkpụrụ pH dị iche iche
HEC n'ozuzu nwere ezigbo nkwụsi ike n'okpuru ọnọdụ acidic na alkaline. Kpọmkwem, HEC nwere ike idowe viscosity ya na ihe na-eme ka ọ dịkwuo ukwuu n'ọtụtụ gburugburu pH. Nnyocha na-egosi na viscosity na ndim ike nke HEC dịtụ kwụsiri ike n'ime pH nso nke 3 ruo 12. Nke a na-eme ka HEC bụrụ ihe na-agbanwe agbanwe nke ukwuu na stabilizer n'ọtụtụ ngwa mmepụta ihe na enwere ike iji ya mee ihe n'okpuru ọnọdụ pH dị iche iche.

Otú ọ dị, nkwụsi ike nke HEC nwere ike imetụta na oke pH ụkpụrụ (dị ka pH n'okpuru 2 ma ọ bụ n'elu 13). N'okpuru ọnọdụ ndị a, ụdọ molekụla HEC nwere ike ịnweta hydrolysis ma ọ bụ mmebi, na-ebute mbelata na viscosity ya ma ọ bụ mgbanwe na akụrụngwa ya. Ya mere, iji HEC n'okpuru ọnọdụ ndị a dị oke mkpa chọrọ nlebara anya pụrụ iche na nkwụsi ike ya.

Atụmatụ ngwa
N'ime ngwa bara uru, pH sensitivity nke HEC na-emetụtakwa ihe ndị ọzọ, dị ka okpomọkụ, ike ionic, na polarity nke ihe mgbaze. N'ime ngwa ụfọdụ, ọ bụ ezie na mgbanwe pH nwere ntakịrị mmetụta na HEC, ihe ndị ọzọ gburugburu ebe obibi nwere ike ime ka mmetụta a dịkwuo elu. Dịka ọmụmaatụ, n'okpuru ọnọdụ okpomọkụ dị elu, ụdọ molekụla HEC nwere ike ịgbanye ngwa ngwa, si otú a na-enwe mmetụta dị ukwuu na arụmọrụ ya.

Na mgbakwunye, na ụfọdụ usoro, dị ka emulsions, gels na covers, HEC na-ejikarị eme ihe na ihe ndị ọzọ (dị ka surfactants, salts ma ọ bụ acid-base regulators). N'ebe a, ọ bụ ezie na HEC adịghị emetụ n'ahụ pH n'onwe ya, ihe ndị ọzọ a nwere ike imetụta ọrụ HEC n'ụzọ na-apụtaghị ìhè site n'ịgbanwe pH. Dịka ọmụmaatụ, ọnọdụ ụgwọ nke ụfọdụ surfactants na-agbanwe na ụkpụrụ pH dị iche iche, nke nwere ike imetụta mmekọrịta dị n'etiti HEC na surfactants, si otú ahụ na-agbanwe rheological Njirimara nke ngwọta.

HEC bụ polymer na-abụghị ionic nke na-adịghị emetụ n'ahụ na pH ma nwee arụmọrụ dị mma na nkwụsi ike n'elu oke pH. Nke a na-eme ka ọ bụrụ nke ọdabara n'ọtụtụ ngwa, ọkachasị ebe achọrọ arụmọrụ kwụsiri ike nke ndị na-eme ihe nkiri na ndị na-eme ihe nkiri. Otú ọ dị, ọ ka dị mkpa ịtụle otú nkwụsi ike na ịrụ ọrụ nke HEC nwere ike isi metụta n'okpuru ọnọdụ pH dị oke egwu ma ọ bụ mgbe ejiri ya na ihe ndị ọzọ nwere mmetụta pH. Maka nsogbu uche pH na ngwa ngwa, a na-atụ aro ka ịme nyocha na nkwenye kwekọrọ tupu iji ya eme ihe iji hụ na HEC nwere ike ịrụ ọrụ nke ọma n'okpuru ọnọdụ ndị a tụrụ anya ya.


Oge nzipu: Ọgọst-19-2024
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