Focus on Cellulose ethers

Ogo cellulose hpmc na-ekpebi ịdị mma nke ngwa agha

Ogo cellulose hpmc na-ekpebi ịdị mma nke ngwa agha

Na ngwa agha agwakọta akọrọ, mgbakwunye nke hydroxypropyl methylcellulose HPMC dị ala, mana ọ nwere ike melite arụmọrụ ngwa agha mmiri, yana ọ bụ ihe mgbakwunye bụ isi na-emetụta arụmọrụ nke ngwa agha. Cellulose ethers nwere ogo dị iche iche nke viscosity na mgbakwunye na-enwe mmetụta dị mma na arụmọrụ nke ngwa ngwa ntụ ntụ. Ka ọ dị ugbu a, ọtụtụ ngwa agha masonry na plasta adịghị arụ ọrụ njide mmiri na-adịghị mma, na slurry mmiri ga-ekewa mgbe nkeji ole na ole guzoro. Njide mmiri bụ ọrụ dị mkpa nke methyl cellulose ether, ọ bụkwa arụmọrụ nke ọtụtụ ndị na-emepụta ihe ọkụkụ na-ekpo ọkụ na-ekpo ọkụ, karịsịa ndị nọ na mpaghara ndịda nke nwere okpomọkụ dị elu, na-aṅa ntị. Ihe ndị na-emetụta mmetụta njide mmiri nke mmiri ntụ ntụ akọrọ gụnyere ọnụọgụ HPMC agbakwunyere, viscosity nke HPMC, ịdị mma nke ihe na okpomọkụ nke gburugburu ebe obibi.

1. Echiche: Cellulose ether bụ polymer sịntetik nke sitere na cellulose eke sitere na mgbanwe kemịkalụ. Cellulose ether bụ ihe sitere na cellulose eke. Ihe mmepụta nke cellulose ether dị iche na polymers sịntetik. Ihe kachasị mkpa ya bụ cellulose, ngwakọta polymer eke. N'ihi ihe dị iche iche nke usoro cellulose eke, cellulose n'onwe ya enweghị ike imeghachi omume na ndị ọrụ etherification. Otú ọ dị, mgbe ọgwụgwọ nke onye na-amụba ihe, a na-ebibi njikọ siri ike hydrogen n'etiti ụdọ molecular na agbụ, na ntọhapụ na-arụ ọrụ nke hydroxyl otu na-aghọ cellulose alkali na-emeghachi omume. Nweta cellulose ether. Njirimara nke cellulose ethers na-adabere n'ụdị, ọnụ ọgụgụ na nkesa nke ndị nọchiri anya ya. Nkewa nke cellulose ethers na-adaberekwa n'ụdị ihe ngbanwe, ogo nke etherification, solubility na ngwa ngwa metụtara ya. Dị ka ụdị ihe ndị na-anọchi anya na eriri molecular, enwere ike kewaa ya na monoether na ngwakọta ether. HPMC anyị na-ejikarị bụ ether agwakọta. Hydroxypropyl methylcellulose ether HPMC bụ ngwaahịa enwetara site na iji otu methoxy dochie akụkụ nke otu hydroxyl na unit yana akụkụ ọzọ nwere otu hydroxypropyl. Usoro nhazi bụ [C6H7O2(OH)3-mn(OCH3)m[OCH2CH(OH)) CH3] n] x

A na-ejikarị HPMC na ihe owuwu ụlọ, mkpuchi latex, ọgwụ, kemịkalụ kwa ụbọchị, wdg. Ejiri ya dị ka thickener, onye na-ejigide mmiri, stabilizer, dispersant na onye na-emepụta ihe nkiri.

2. Njide mmiri nke cellulose ether: Na mmepụta nke ihe owuwu ụlọ, karịsịa akọrọ ntụ ntụ ntụ ntụ, cellulose ether na-arụ ọrụ na-adịghị agbanwe agbanwe, karịsịa na mmepụta nke ngwa agha pụrụ iche (mgbazigharị ngwa ngwa), ọ dị mkpa na ihe dị mkpa. Ọrụ dị mkpa nke mmiri-soluble cellulose ether na ngwa agha tumadi nwere akụkụ atọ, otu bụ magburu onwe mmiri njigide ikike, nke ọzọ bụ mmetụta na agbanwe agbanwe na thixotropy nke ngwa agha, na nke atọ bụ mmekọrịta na ciment. Mmetụta njide mmiri nke cellulose ether na-adabere na mmịnye mmiri nke oyi akwa isi, ihe mejupụtara nke ngwa agha ahụ, ọkpụrụkpụ nke akwa akwa akwa akwa akwa akwa akwa akwa akwa akwa akwa, mmiri chọrọ ngwa ngwa, na oge nhazi nke ihe nhazi. Njide mmiri nke cellulose ether n'onwe ya sitere na solubility na akpịrị ịkpọ nkụ nke cellulose ether n'onwe ya. Dị ka anyị niile maara, ọ bụ ezie na cellulose molecular chain nwere ọnụ ọgụgụ buru ibu nke ukwuu hydratable OH otu, ọ bụghị soluble na mmiri, n'ihi na cellulose Ọdịdị nwere nnukwu ogo nke crystallinity. Ike hydration nke otu hydroxyl naanị ezughị iji kpuchie njikọ njikọ hydrogen siri ike na ndị agha van der Waals n'etiti ụmụ irighiri ihe. Ya mere, ọ na-aza naanị ma ọ naghị agbaze na mmiri. Mgbe a na-ewebata ihe ngbanwe n'ime agbụ molekụla, ọ bụghị naanị ihe mgbakwunye na-emebi yinye hydrogen, kamakwa a na-emebi njikọ interchain hydrogen n'ihi ịgbanye ihe nọchiri anya n'etiti ụdọ ndị dị n'akụkụ. Ka nnukwu ihe nọchiri anya ya, ka ebe dị anya n'etiti ụmụ irighiri ihe. Nke ka ukwuu na anya. Mmetụta dị ukwuu nke ibibi njikọ hydrogen, cellulose ether na-aghọ mmiri na-agbaze mgbe cellulose lattice gbasaa na ngwọta na-abanye, na-eme ka ngwọta dị elu nke viscosity. Mgbe okpomọkụ na-ebili, hydration nke polymer na-ada mbà, a na-achụpụkwa mmiri n'etiti agbụ. Mgbe mmetụta akpịrị ịkpọ nkụ zuru ezu, ụmụ irighiri ihe ndị ahụ na-amalite ịgbakọta, na-akpụ ihe nhazi netwọk akụkụ atọ wee tụgharịa. Ihe ndị na-emetụta njide mmiri nke ngwa agha gụnyere viscosity nke cellulose ether, ego a gbakwunyere, ịdị mma nke ihe na okpomọkụ eji eme ihe. Ka viscosity nke cellulose ether dị ukwuu, otú ahụ ka ọrụ njigide mmiri dị mma. N'ikwu okwu n'ozuzu, ka viscosity dị elu, ka mma na-ejide mmiri. Ihe dị elu nke viscosity, otú ahụ ka ọ na-apụta ìhè nke ọma mmetụta na ngwa ngwa, ma ọ bụghị kpọmkwem. Nke dị elu nke viscosity, otú ahụ ka ngwa ngwa mmiri ga-adịkwu viscous, ya bụ, n'oge a na-ewu ihe, a na-egosipụta ya dị ka ịrapara na scraper na nnukwu adhesion na mkpụrụ. Mana ọ naghị enye aka ịbawanye ike nhazi nke ngwa agha mmiri n'onwe ya. N'oge a na-ewu ụlọ, arụ ọrụ mgbochi sag abụghị ihe doro anya. Ọnụ ọgụgụ dị ukwuu nke cellulose ether agbakwunyere na ngwa agha ahụ, ka mma na-arụ ọrụ njide mmiri, na elu viscosity, ka mma na-arụ ọrụ njide mmiri. N'ihe gbasara nha urughuru, ka mma nke urughuru, mma na-ejigide mmiri. Mgbe nnukwu akụkụ nke cellulose ether batara na mmiri, elu ahụ na-agbaze ozugbo ma mepụta gel iji kechie ihe ahụ iji gbochie ụmụ irighiri mmiri na-aga n'ihu na-abanye. Mgbe ụfọdụ, a pụghị ịgbasa ya n'otu n'otu ma gbazee ọbụlagodi mgbe ọ kpalitere ogologo oge, na-akpụ ihe ngwọta flocculent na urukpuru ma ọ bụ agglomeration. Ọ na-emetụta oke mmiri nke cellulose ether, na solubility bụ otu n'ime ihe ndị na-ahọrọ cellulose ether. Ịdị mma bụkwa ihe ngosi arụmọrụ dị mkpa nke methyl cellulose ether. The HPMC eji maka akọrọ ntụ ntụ ngwa agha chọrọ ka ntụ ntụ, na obere mmiri ọdịnaya, na fineness na-achọkwa 20% ~ 60% nke urughuru size na-erughị 63um. Ịdị mma na-emetụta solubility nke methyl cellulose ether. Oke MC na-abụkarị granular, ọ dịkwa mfe igbari n'ime mmiri na-enweghị agglomeration, mana ọnụego mgbasa na-adị ngwa ngwa, n'ihi ya, ọ naghị adabara iji mee ihe na ntụ ntụ ntụ. N'ime ngwa ngwa ntụ ntụ akọrọ, MC na-agbasasị n'etiti ihe simenti dị ka nchịkọta, ezigbo filler na ciment, na naanị ezigbo ntụ ntụ nwere ike izere methyl cellulose ether agglomeration mgbe ị na-agwakọta mmiri. Mgbe a na-agbakwunye HPMC na mmiri iji gbazee agglomerates, ọ na-esiri ike ịgbasa na igbari. Maka ngwa agha a na-efesa na-arụ ọrụ, ihe a chọrọ maka ịdị mma dị elu n'ihi obere oge ịgwakọta. Ịdị mma nke HPMC nwekwara mmetụta ụfọdụ na njide mmiri ya. N'ikwu okwu n'ozuzu, maka methyl cellulose ethers nwere otu viscosity mana ịdị mma dị iche iche, n'okpuru otu ego agbakwunyere, nke kachasị mma na-eme ka mmetụta njide mmiri dịkwuo mma. Njide mmiri nke HPMC na-emetụtakwa ọnọdụ okpomọkụ a na-eji, na njide mmiri nke methyl cellulose ether na-ebelata na mmụba nke okpomọkụ. Otú ọ dị, n'ezie ngwa ngwa, akọrọ ntụ ntụ ngwa agha na-ejikarị na-ekpo ọkụ substrates na elu okpomọkụ (elu 40 degrees) n'ọtụtụ gburugburu ebe obibi, dị ka mpụta mgbidi putty plasta n'okpuru anyanwụ n'oge okpomọkụ, nke na-emekarị accelerates Ịgwọ ciment na hardening. ngwa ngwa ntụ ntụ akọrọ. Mbelata nke njide mmiri na-eduga na mmetụta doro anya na ma arụmọrụ na nkwụsị mgbawa na-emetụta, ọ dịkwa oke mkpa iji belata mmetụta nke ihe okpomọkụ n'okpuru ọnọdụ a.

3. Thickening na thixotropy nke cellulose ether: Ọrụ nke abụọ nke cellulose ether-thickening mmetụta na-adabere na: ogo nke polymerization nke cellulose ether, ngwọta ngwọta, okpomọkụ na ọnọdụ ndị ọzọ. Ngwongwo gelling nke ihe ngwọta bụ ihe pụrụ iche na alkyl cellulose na ihe ndị gbanwetụrụ. Njirimara gelation metụtara ogo ngbanwe, ntinye ngwọta na ihe mgbakwunye. Maka ihe nrụpụta hydroxyalkyl gbanwetụrụ, njirimara gel na-emetụtakwa ogo mgbanwe nke hydroxyalkyl. N'ihi na obere viscosity HPMC ngwọta, 10% -15% ịta ngwọta nwere ike kwadebere, ọkara viscosity HPMC nwere ike kwadebere 5%-10% ngwọta, na elu viscosity HPMC nwere ike na-akwadebe 2% -3% ngwọta, na viscosity. nke cellulose ether na-abụkarị grading na-eji 1%-2% ngwọta. Ether cellulose dị arọ dị elu nwere arụmọrụ dị elu. Polymers nwere ịdị arọ molekụla dị iche iche nwere viscosities dị iche iche n'otu ngwọta ntinye uche. Ọkwa dị elu nke polymerization. Enwere ike nweta viscosity ebumnuche naanị site n'ịgbakwụnye nnukwu ether cellulose dị arọ dị ala. Viscosity ya nwere ntakịrị ịdabere na ọnụ ọgụgụ shear, na viscosity dị elu na-erute viscosity lekwasịrị anya, na ihe mgbakwunye a chọrọ dị ntakịrị, na viscosity na-adabere na nrụpụta ọrụ. Ya mere, iji nweta ihe na-agbanwe agbanwe, a ghaghị ijide n'aka na ether cellulose ether (ntụkwasị uche nke ngwọta) na viscosity ngwọta ga-ekwe nkwa. The gel okpomọkụ nke ngwọta na-ebelata linearly na-abawanye nke ịta nke ihe ngwọta, na gels na ụlọ okpomọkụ mgbe eru a ụfọdụ ịta. The gelling ịta ahụhụ nke HPMC dịtụ elu na ụlọ okpomọkụ. Enwere ike ịhazi nkwekọ site na ịhọrọ nha nha na ịhọrọ cellulose ethers nwere ogo mgbanwe dị iche iche. Ihe a na-akpọ mgbanwe bụ iwebata ụfọdụ ngbanwe nke otu hydroxyalkyl na nhazi ọkpụkpụ nke MC. Site n'ịgbanwe ụkpụrụ ngbanwe nke ndị nnọchi anya abụọ ahụ, ya bụ, ụkpụrụ nnọchi DS na ms nke ndị otu methoxy na hydroxyalky nke anyị na-ekwukarị. Enwere ike nweta ọrụ dị iche iche chọrọ nke cellulose ether site n'ịgbanwe ụkpụrụ nnọchi anya nke ihe abụọ a nọchiri anya ya. Mmekọrịta dị n'etiti nkwụsi ike na mgbanwe: mgbakwunye cellulose ether na-emetụta mmiri oriri nke ngwa agha, na-agbanwe mmiri na-ejikọta mmiri na ciment bụ mmetụta na-eme ka ọ dịkwuo elu, nke dị elu nke usoro onunu ogwu, na-abawanye oriri mmiri. Cellulose ethers nke a na-eji na ihe owuwu ụlọ ntụ ntụ ga-agbaze ngwa ngwa na mmiri oyi ma nye usoro kwesịrị ekwesị maka usoro ahụ. Enwekwara mmekọrịta dị mma n'ahịrị n'etiti nkwụsi ike nke cement ciment na usoro nke cellulose ether. Cellulose ether nwere ike ịbawanye viscosity nke ngwa agha. Ka usoro onunu ogwu buru ibu, ka mmetụta ya pụta ìhè. Ihe ngwọta dị elu nke cellulose ether aqueous nwere nnukwu thixotropy, nke bụkwa isi njirimara cellulose ether. Ya mere, cellulose ethers nke otu viscosity ọkwa mgbe niile na-egosipụta otu rheological Njirimara ma ọ bụrụhaala na ịta na okpomọkụ na-anọgide na-adịgide adịgide. A na-emepụta gels ihe owuwu mgbe a na-ebuli okpomọkụ elu, na oke thixotropic na-eme. Nnukwu ntinye uche na obere viscosity cellulose ethers na-egosi thixotropy ọbụna n'okpuru gel okpomọkụ. Ngwongwo a bara uru nke ukwuu maka ngbanwe nke larịị na sagging na-ewu ụlọ mgbidi. Ọ dị mkpa ka a kọwaa ebe a na elu viscosity nke cellulose ether, mma njigide mmiri, ma elu nke viscosity, elu nke ikwu molekụla arọ nke cellulose ether, na kwekọrọ ekwekọ mbelata ya solubility, nke nwere mmetụta ọjọọ. na ngwa agha ịta na ịrụ ọrụ ihe owuwu. Ihe dị elu nke viscosity, otú ahụ ka ọ na-apụta ìhè nke ọma mmetụta na ngwa agha ahụ, ma ọ bụghị nke zuru oke. Ụfọdụ obere viscosity na obere viscosity, mana cellulose ether gbanwetụrụ nwere arụmọrụ ka mma n'ịkwalite ike nhazi nke ngwa agha mmiri. Site na mmụba nke viscosity, njigide mmiri nke cellulose ether na-akawanye mma.

4. Mbelata nke cellulose ether: Ọrụ nke atọ nke cellulose ether bụ igbu oge usoro hydration nke ciment. Cellulose ether na-enye ngwa agha nwere ihe bara uru dị iche iche, ma na-ebelata okpomọkụ nke mbụ nke ciment ma na-egbu oge usoro hydration ike nke ciment. Nke a adịghị mma maka iji ngwa agha na mpaghara oyi. A na-akpata mmetụta nkwụghachi azụ a site na ntinye nke cellulose ether molecules na ngwaahịa hydration dị ka CSH na ca (OH) 2. N'ihi mmụba nke viscosity nke ngwọta pore, cellulose ether na-ebelata mmegharị nke ion na ngwọta, si otú ahụ na-egbu oge usoro hydration. N'ịdị elu nke cellulose ether na ihe gel ịnweta, ka mmetụta nke igbu oge hydration na-apụtawanye ìhè. Cellulose ether ọ bụghị naanị na-egbu oge nhazi, kamakwa ọ na-egbu oge usoro siri ike nke usoro ciment mortar. Mmetụta retarding nke cellulose ether na-adabere ọ bụghị nanị na ntinye ya na sistemụ ịnweta gel, kamakwa na usoro kemịkal. Ka mmetụta nkwụsị nke cellulose ether dịkwuo mma, ka mmetụta nkwụsịghachi nke hydrophilic dị ike karịa ngbanwe nke mmiri na-abawanye. Otú ọ dị, viscosity nke cellulose ether enwechaghị mmetụta na ciment hydration kinetics. Site na mmụba nke cellulose ether ọdịnaya, nhazi oge nke ngwa agha na-abawanye nke ukwuu. Enwere ezigbo mmekọrịta na-adịghị n'ịntanetị n'etiti mmalite mmalite oge nke ngwa agha na ọdịnaya nke cellulose ether, yana ezigbo njikọ dị n'etiti oge nhazi ikpeazụ na ọdịnaya nke cellulose ether. Anyị nwere ike ijikwa oge arụ ọrụ nke ngwa agha ahụ site n'ịgbanwe ọnụọgụ cellulose ether. N'ịchịkọta, na ngwa ngwa agwakọta dị njikere, cellulose ether na-ekere òkè na njide mmiri, ịgbatị, na-egbu oge ike hydration ciment, na imeziwanye arụmọrụ ihe owuwu. Ikike njide mmiri dị mma na-eme ka hydration ciment zuo oke, nwere ike melite viscosity mmiri nke ngwa mmiri mmiri, na-abawanye ike njikọ nke ngwa agha, ma dozie oge. Ịgbakwunye cellulose ether na ngwa agha ịgbasa igwe nwere ike imeziwanye ọrụ ịgbasa ma ọ bụ ịgbapụta na ike nhazi nke ngwa agha ahụ. Ya mere, a na-eji cellulose ether eme ihe n'ọtụtụ ebe dị ka ihe mgbakwunye dị mkpa na ngwa ngwa agwakọta.


Oge nzipu: Jan-23-2023
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