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. Anyị na-ejikarị mc dị ka monoether, yana HPmc dị ka ether agwakọta. Methyl cellulose ether mc bụ ngwaahịa a na-emepụta mgbe otu hydroxyl nọ na nkeji glucose nke cellulose eke site na methoxy Group dochie ya. Ọ bụ ngwaahịa enwetara site na iji otu methoxy dochie akụkụ nke hydroxypropyl na otu akụkụ nke otu hydroxypropyl. Usoro nhazi bụ [C6H7O2(OH)3-mn(OCH3)m[OCH2CH(OH)CH3]n]x Hydroxyethyl methyl cellulose ether HEmc, ndị a bụ ụdị ndị a na-ejikarị na-ere n'ahịa.
N'ihe gbasara solubility, enwere ike kewaa ya na ionic na ndị na-abụghị ionic. Mmiri-soluble na-abụghị ionic cellulose ethers bụ tumadi mejupụtara abụọ usoro nke alkyl ethers na hydroxyalkyl ethers. A na-ejikarị Ionic Cmc eme ihe n'ihe ndị sịntetịt, mbipụta textile na akwa, nchọpụta nri na mmanụ. Ndị na-abụghị ionic mc, HPmc, HEmc, wdg na-ejikarị eme ihe na ihe owuwu, mkpuchi latex, ọgwụ, kemịkalụ kwa ụbọchị, wdg A na-eji dị ka thickener, onye na-ejigide mmiri, stabilizer, dispersant, film forming agent.
Njide mmiri nke cellulose ether
Na mmepụta nke ihe owuwu ụlọ, karịsịa ngwa ngwa agwakọta akọrọ, cellulose ether na-arụ ọrụ na-enweghị atụ, karịsịa n'ịmepụta ngwa agha pụrụ iche (mgbochi a gbanwere), ọ bụ ihe 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.
Ihe dị elu nke viscosity nke cellulose ether, na-eme ka ọrụ njigide mmiri dị mma, na elu viscosity nke ngwọta polymer. Dabere na ịdị arọ nke molekul (polymerization degrees) nke polymer, a na-ekpebikwa ya site na ogologo ogologo nke usoro ihe omimi na ọdịdị nke agbụ ahụ, na nkesa nke ụdị na ọnụọgụ nke ihe ndị na-anọchi anya na-emetụtakwa ya kpọmkwem viscosity nso. [η] = kmα
[η] viscosity dị mkpa nke ngwọta polymer
m polymer arọ molekul
α polymer njirimara mgbe niile
K viscosity ngwọta ọnụọgụ
Viscosity nke ngwọta polymer na-adabere na ịdị arọ molekụla nke polymer. Viscosity na ntinye nke ngwọta cellulose ether metụtara ngwa na mpaghara dị iche iche. Ya mere, nke ọ bụla cellulose ether nwere ọtụtụ dị iche iche viscosity nkọwa, na ukpụhọde nke viscosity bụ tumadi ghọtara site nbibi nke alkali cellulose, ya bụ, na-agbaji nke cellulose molekul chains.
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.
Maka oke urughuru, ka mma ahụ dị mma, ka mma na-ejigide mmiri (lee foto 3). 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.
Thicking na Thixotropy nke Cellulose Ether
Ọrụ nke abụọ nke cellulose ether - ndim na-adabere na: ogo nke polymerization nke cellulose ether, ngwọta ngwọta, shear ọnụego, 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 mc na HPmc na ala viscosity, 10% -15% ịta ngwọta nwere ike kwadebere, 5% -10% ngwọta nwere ike kwadebere maka ọkara viscosity mc na HPmc, na 2% -3% ngwọta nwere ike kwadebere maka elu viscosity mc na HPmc, na-abụkarị nkewa nke viscosity nke cellulose ether bụkwa 1%-2% ngwọta. Ether cellulose dị arọ nke dị elu nwere arụmọrụ njupụta dị elu. N'otu ngwọta ntinye uche ahụ, polymers nwere ịdị arọ dị iche iche nwere viscosities dị iche iche. Ọkwa dị elu. 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. Ntinye uche gelation nke HPmc dị elu na okpomọkụ ụlọ.
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 ihe dị iche iche chọrọ ịrụ ọrụ nke cellulose ether site n'ịgbanwe ụkpụrụ nnọchi anya nke ihe abụọ a nọchiri anya ya.
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. Ọ bụrụ na enyere ya ọnụ ọgụgụ shear, ọ ka na-aghọ flocculent na colloidal block, nke bụ ngwaahịa na-adịghị mma ma ọ bụ na-adịghị mma.
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 buru ibu, ka mmetụta ya na-apụta ìhè karị, lee foto 6
Nnukwu viscosity cellulose ether aqueous ngwọta nwere thixotropy dị elu, nke bụkwa isi njirimara cellulose ether. Aqueous ngwọta nke Mc ụdị polymers na-enwekarị pseudoplastic na ndị na-abụghị thixotropic fluidity n'okpuru ha gel okpomọkụ, ma Newtonian eruba Njirimara na ala shiee ọnụego. Pseudoplasticity na-abawanye site na ịdị arọ molekụla ma ọ bụ itinye uche nke cellulose ether, n'agbanyeghị ụdị nnọchi na ogo nke nnọchi. Ya mere, cellulose ethers nke otu viscosity ọkwa, n'agbanyeghị mc, HPmc, HEmc, ga-mgbe na-egosi otu rheological Njirimara ma ọ bụrụhaala na ịta na okpomọkụ na-nọgidere 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.
Oge nzipu: Nov-22-2022