Focus on Cellulose ethers

Njirimara kemịkalụ na njikọ nke hydroxypropyl methylcellulose (HMPC)

Hydroxypropyl methylcellulose (HPMC) bụ polymer sịntetik ewepụtara na cellulose ma na-ejikarị eme ihe dị ka thickener, emulsifier, na stabilizer na ụlọ ọrụ dị iche iche dị ka nri, ọgwụ na ihe ịchọ mma. HMPC bụ ihe nrụpụta hydroxypropylated nke methylcellulose (MC), ether nonionic cellulose ether nwere soluble mmiri nke mejupụtara nkeji methoxylated na hydroxypropylated cellulose. A na-eji HMPC eme ihe n'ọtụtụ ebe dị ka ihe na-akpali akpali na usoro ọgwụ n'ihi adịghị egbu egbu ya, biocompatibility, na biodegradability.

Njirimara kemịkalụ HMPC:

Njirimara kemịkalụ nke HMPC bụ n'ihi ọnụnọ nke hydroxyl na ether dị n'ụdị molekụla ya. Enwere ike ịrụ ọrụ otu hydroxyl nke cellulose site na mmeghachi omume kemịkalụ dị iche iche, dị ka etherification, esterification, na oxidation, iji webata otu ọrụ dị iche iche n'ime ọkpụkpụ polymer. HMPC nwere ma methoxy (-OCH3) na hydroxypropyl (-OCH2CHOHCH3), nke enwere ike ịchịkwa iji nye ihe dị iche iche dị ka solubility, viscosity na gelation.

HMPC na-agbaze nke ukwuu na mmiri, na-emepụta ngwọta doro anya, viscous na obere mkpokọta. Enwere ike gbanwee viscosity nke ngwọta HMPC site na ịhazigharị ogo nnọchi (DS) nke otu hydroxypropyl, nke na-ekpebi ọnụọgụ saịtị hydroxyl gbanwetụrụ n'otu glucose. Nke dị elu nke DS, na-ebelata solubility na elu viscosity nke ngwọta HMPC. Enwere ike iji ihe onwunwe a jikwaa ntọhapụ nke ihe ndị na-arụsi ọrụ ike site na usoro ọgwụ.

HMPC na-egosipụtakwa omume pseudoplastic, nke pụtara na viscosity na-ebelata na ọnụ ọgụgụ shear na-abawanye. Ngwongwo a na-eme ka ọ dị mma dị ka onye na-agbapụta mmiri maka nhazi mmiri nke kwesịrị iguzogide ike ịkwa akwa n'oge nhazi ma ọ bụ ngwa.

HMPC kwụsiri ike ruo n'otu ọnọdụ okpomọkụ, nke ọ na-amalite imebi. Ọnọdụ nbibi nke HMPC na-adabere na DS na ntinye nke polymer na ngwọta. A na-akọ na oke ọnọdụ okpomọkụ nke HMPC bụ 190-330 Celsius.

Nchịkọta nke HMPC:

A na-emepụta HMPC site na mmeghachi omume etherification nke cellulose na propylene oxide na methylethylene oxide n'ihu ihe na-eme ka alkaline. Mmeghachi omume na-aga n'ihu na nzọụkwụ abụọ: nke mbụ, a na-eji propylene oxide dochie otu methyl nke cellulose, mgbe ahụ, a na-eji methyl ethylene oxide dochie otu hydroxyl. Enwere ike ịchịkwa DS nke HMPC site n'ịgbanwe nha molar nke propylene oxide na cellulose n'oge usoro nhazi.

A na-emekarị mmeghachi omume ahụ na mmiri mmiri na-ekpo ọkụ na elu okpomọkụ na nrụgide. Ihe na-akpatakarị ihe na-abụkarị sodium ma ọ bụ potassium hydroxide, nke na-eme ka mmeghachi omume nke otu cellulose hydroxyl dị na mgbanaka epoxide nke propylene oxide na methylethylene oxide. A na-ewepụ ngwaahịa mmeghachi omume ahụ, saa ya ma kpoo ya iji nweta ngwaahịa HMPC ikpeazụ.

Enwere ike ijikọ HMPC site na iji propylene oxide na epichlorohydrin meghachi omume cellulose n'ihu ihe ndị na-eme acid. A na-eji usoro a, nke a maara dị ka usoro epichlorohydrin, na-emepụta ihe ndị na-emepụta cationic cellulose, bụ ndị a na-akwụ ụgwọ nke ọma n'ihi ọnụnọ nke ammonium quaternary.

na ngwụcha:

HMPC bụ polymer multifunctional nwere ezigbo kemịkalụ dabara adaba maka ngwa dị iche iche na ụlọ ọrụ dị iche iche. Njikọ nke HMPC gụnyere mmeghachi omume etherification nke cellulose na propylene oxide na methylethylene oxide n'ihu ihe na-eme ka alkaline ma ọ bụ ihe na-emepụta acidic. Enwere ike idozi akụrụngwa nke HMPC site na ịchịkwa DS na itinye uche nke polymer. Nchekwa na biocompatibility nke HMPC na-eme ka ọ bụrụ nhọrọ dị mma maka usoro ọgwụ.


Oge nzipu: Sep-18-2023
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