Cellulose ether bụ polima sịntetik nke e ji cellulose eke mee dị ka ihe e ji emepụta site na mgbanwe kemịkalụ. Cellulose ether bụ ihe sitere na cellulose eke, mmepụta cellulose ether na polima sịntetik dị iche, ihe kachasị mkpa ya bụ cellulose, ngwakọta polymer eke. N'ihi njirimara nke nhazi cellulose eke, cellulose n'onwe ya enweghị ike imeghachi omume na ihe na-emepụta etherifying. Mana mgbe ọgwụgwọ nke ihe na-eme ka ọzịza pụta, e bibiri njikọ hydrogen siri ike dị n'etiti agbụ na agbụ molekul, a tọhapụkwara ọrụ nke otu hydroxyl n'ime cellulose alkali nwere ikike mmeghachi omume, a na-enwetakwa cellulose ether site na mmeghachi omume nke ihe na-emepụta etherifying - otu OH n'ime otu OR.
Njirimara nke ether cellulose na-adabere n'ụdị, ọnụọgụ na nkesa nke ihe ndị na-anọchi ya. Nhazi nke ether cellulose daberekwa n'ụdị ihe ndị na-anọchi ya, ọkwa nke etherification, ike ịgbaze na ojiji ndị yiri ya nwere ike kewaa. Dịka ụdị ihe ndị na-anọchi ya dị na yinye molekul si dị, enwere ike kewaa ya n'ime otu ether na ether agwakọtara agwakọtara. A na-ejikarị MC eme ihe dị ka otu ether, ebe HPmc bụ ether agwakọtara agwakọtara. Methyl cellulose ether MC bụ ihe e ji emepụta glucose cellulose eke na hydroxyl bụ methoxide nke e ji usoro nhazi ngwaahịa dochie [CO H7O2 (OH) 3-H (OCH3) H] X, hydroxypropyl methyl cellulose ether HPmc bụ ihe e ji emepụta hydroxyl bụ akụkụ nke methoxide nke e tinyere, akụkụ ọzọ nke ngwaahịa hydroxypropyl nke e tinyere dochie, Usoro nhazi bụ [C6H7O2 (OH) 3-MN (OCH3) M [OCH2CH (OH) CH3] N] X na hydroxyethyl methyl cellulose ether HEmc, nke a na-ejikarị eme ihe ma na-ere n'ahịa.
Site na ihe mgbaze, enwere ike kewaa ụdị ionic na ụdị non-ionic. Ether cellulose nke na-agbaze mmiri na-abụkarị nke alkyl ether na hydroxyl alkyl ether nwere usoro abụọ dị iche iche. A na-ejikarị Ionic Cmc eme ihe n'ime ihe e ji asa ákwà, ákwà, mbipụta, nri na mmanụ ala. A na-ejikarị ya eme ihe na-abụghị ionic MC, HPmc, HEmc na ihe ndị ọzọ a na-ejikarị eme ihe n'ihe owuwu ụlọ, mkpuchi latex, ọgwụ, kemịkalụ kwa ụbọchị na akụkụ ndị ọzọ. Dịka ihe na-eme ka ihe sie ike, ihe na-ejide mmiri, ihe na-eme ka ihe sie ike, ihe na-agbasa ihe, ihe na-akpụ ihe nkiri.
Ijide mmiri Cellulose ether
N'imepụta ihe owuwu ụlọ, karịsịa ngwa agha agwakọtara akọrọ, cellulose ether na-arụ ọrụ a na-apụghị ịgbanwe agbanwe, ọkachasị n'imepụta ngwa agha pụrụ iche (ngwa agha agbanwere agbanwe), bụ akụkụ dị oke mkpa.
Ọrụ dị mkpa nke cellulose ether nke na-agbaze mmiri na ngwa agha nwere akụkụ atọ, otu bụ ikike ijide mmiri nke ọma, nke abụọ bụ mmetụta nke nguzosi ike na thixotropy, nke atọ bụkwa mmekọrịta ya na simenti.
Mmiri Cellulose ether na-ejide, dabere na ntọala hydroscopicity, nhazi nke moto, ọkpụrụkpụ nke oyi akwa moto, mkpa mmiri moto, oge condensation ihe condensation. Nchekwa mmiri nke cellulose ether sitere na ịgbaze na mmiri nke cellulose ether n'onwe ya. A maara nke ọma na agbụ molekul cellulose, ọ bụ ezie na ha nwere ọtụtụ otu OH dị oke mmiri mmiri, anaghị agbaze na mmiri n'ihi nhazi kristal ha dị elu. Ike mmiri nke otu hydroxyl naanị ezughị iji kwụọ ụgwọ maka njikọ hydrogen intermolecular siri ike na ike van der Waals. Mgbe etinyere ihe ndị a n'ime agbụ molekul, ọ bụghị naanị ihe ndị a na-etinye na-ebibi agbụ hydrogen, kamakwa a na-agbaji njikọ hydrogen interchain n'ihi njikọ nke ihe ndị a na-etinye n'etiti agbụ. Ka ihe ndị a na-etinye na-ebu ibu, otú ahụ ka anya dị n'etiti molekul na-abawanye. Ka mbibi nke mmetụta njikọ hydrogen ka ukwuu, mgbasa nke cellulose lattice, ngwọta n'ime cellulose ether na-aghọ mmiri na-agbaze, nhazi nke ngwọta viscosity dị elu. Ka okpomọkụ na-arị elu, mmiri nke polima ahụ na-ebelata, mmiri dị n'etiti agbụ ndị ahụ na-apụkwa. Mgbe mmetụta nke mmiri na-agbaze ezu, molekul ndị ahụ na-amalite ịchịkọta ma jel ahụ na-agbapụta na netwọk akụkụ atọ. Ihe ndị na-emetụta njide mmiri nke mortar gụnyere viscosity cellulose ether, dose, ịdị mma nke ihe na okpomọkụ ọrụ.
Ka viscosity nke cellulose ether na-abawanye, otú ahụ ka arụmọrụ nchekwa mmiri ka mma, viscosity nke ngwọta polymer ka mma. A na-ekpebikwa ibu molekul (ogo polymerization) nke polymer site na ogologo na ọdịdị nke nhazi molekul nke yinye ahụ, na nkesa nke ọnụọgụ nke ihe ndị na-anọchi ya na-emetụta oke viscosity ozugbo. [eta] = Km alpha
Viskọs dị n'ime nke ngwọta polymer
Ibu molekụla polima M
α njirimara polymer na-agbanwe agbanwe
Ọnụọgụ ngwọta viscosity K
Ọbara nke ihe ngwọta polima dabere na ibu molekul nke polima ahụ. Ọbara na njupụta nke ihe ngwọta ether cellulose nwere njikọ na ojiji dị iche iche. Ya mere, ether cellulose ọ bụla nwere ọtụtụ nkọwapụta viscosity dị iche iche, njikwa viscosity bụkwa isi site na mmebi nke alkali cellulose, ya bụ mgbawa nke yinye molekul cellulose iji nweta.
Maka nha nke ihe ndị dị n'ime ya, ka ihe ndị dị n'ime ya na-adịkwu mma, otú ahụ ka mmiri na-ejide ya nke ọma. Nnukwu ihe ndị dị n'ime ya na-eme ka mmiri ghara ịbanye, elu ya na-agbaze ozugbo ma na-emepụta gel iji kechie ihe ahụ iji gbochie ihe ndị dị n'ime ya ịbanye, mgbe ụfọdụ, a naghị agbaze ya ruo ogologo oge, ọ naghị adịkwa mfe ịgbaze, nke a na-emepụta ihe ngwọta apịtị ma ọ bụ agglomerate. Ọgba aghara nke ihe ndị dị n'ime ya bụ otu n'ime ihe ndị na-eme ka e nwee cellulose ether.
Mkpọ na thixotropy nke cellulose ether
Mmetụta nke abụọ nke cellulose ether - ọkpụrụkpụ dabere na: ogo polymerization cellulose ether, ntinye nke ngwọta, ọnụego shear, okpomọkụ na ọnọdụ ndị ọzọ. Njirimara gelation nke ngwọta pụrụ iche na cellulose alkyl na ihe ndị sitere na ya agbanwere agbanwe. Àgwà gelation metụtara ogo nnọchi, ntinye nke ngwọta na ihe mgbakwunye. Maka ihe ndị sitere na hydroxyl alkyl gbanwere, njirimara gel na-ejikọkwa na ogo mgbanwe hydroxyl alkyl. Maka ntinye nke ngwọta nke obere viscosity MC na HPmc, enwere ike ịkwadebe ngwọta ntinye nke 10%-15%, enwere ike ịkwadebe MC na HPmc ọkara viscosity ngwọta 5%-10% na nnukwu viscosity MC na HPmc enwere ike ịkwadebe naanị ngwọta 2%-3%, na-abụkarịkwa viscosity nke cellulose ether na-eji ngwọta 1%-2% eme ihe. Oke arụmọrụ nke cellulose ether thickener nke dị n'ime molekul, otu njupụta nke ngwọta ahụ, polima dị iche iche nwere viscosity dị iche iche, viscosity na ibu molekul nwere ike ịpụta dịka ndị a, [η]=2.92×10-2 (DPn) 0.905, DPn bụ nkezi ogo polymerization nke dị elu. Obere molekul cellulose ether iji tinye ihe ndị ọzọ iji nweta viscosity ebumnuche. viscosity ya anaghị adabere na ọnụego shear, viscosity dị elu iji nweta viscosity ebumnuche, ego achọrọ iji tinye obere, viscosity dabere na arụmọrụ thickness. Ya mere, iji nweta nkwekọ ụfọdụ, a ga-ekwe nkwa na a ga-enwe ụfọdụ cellulose ether (ntinye nke ngwọta) na viscosity ngwọta. Okpomọkụ gelation nke ngwọta ahụ belatara n'usoro ka mmụba nke njupụta nke ngwọta ahụ, gelation wee mee na okpomọkụ ụlọ mgbe ọ ruru njupụta ụfọdụ. HPmc nwere njupụta gelation dị elu na okpomọkụ ụlọ.
Enwere ike ịgbanwe nguzozi ahụ site na ịhọrọ nha ihe na cellulose ethers nwere ogo mgbanwe dị iche iche. Ihe a na-akpọ mgbanwe bụ iwebata otu hydroxyl alkyl n'ogo nnọchi ụfọdụ na nhazi ọkpụkpụ nke MC. Site na ịgbanwe ụkpụrụ nnọchi anya nke ihe abụọ ahụ, ya bụ, ụkpụrụ nnọchi anya DS na MS nke otu methoxy na hydroxyl. A chọrọ ihe dị iche iche nke cellulose ether site na ịgbanwe ụkpụrụ nnọchi anya nke ụdị ihe abụọ ahụ.
mmekọrịta dị n'etiti nguzozi na mgbanwe. Na eserese nke 5, itinye cellulose ether na-emetụta oriri mmiri nke moto ma na-agbanwe oke mmiri na-ejikọta mmiri na mmiri na simenti, nke bụ mmetụta siri ike. Ka dose dị elu, otú ahụ ka oriri mmiri na-abawanye.
Cellulose ethers eji arụ ụlọ nwere ntụ ntụ ga-agbaze ngwa ngwa na mmiri oyi ma nye sistemụ ahụ nha kwesịrị ekwesị. Ọ bụrụ na ọnụego nkụcha ka na-agbanwe agbanwe ma na-agbanwe agbanwe, ọ bụ ngwaahịa na-adịghị mma ma ọ bụ nke na-adịghị mma.
Enwekwara ezigbo mmekọrịta dị n'etiti nguzozi nke simenti slurry na usoro nke cellulose ether, cellulose ether nwere ike ime ka viscosity nke ngwa agha dịkwuo elu, ka usoro ọgwụgwọ ahụ na-abawanye, ka mmetụta ya na-apụta ìhè.
Mmiri mmiri Cellulose ether nwere oke viscosity nwere oke thixotropy dị elu, nke bụ otu n'ime njirimara nke cellulose ether. Mmiri mmiri nke ụdị Mc polymers na-enwekarị pseudoplastic, nke na-abụghị thixotropic dị n'okpuru okpomọkụ gel ha, mana ihe ndị Newtonian na-asọ asọ na obere ọnụego shear. Pseudoplasticity na-abawanye ka mmụba nke ibu molekul ma ọ bụ mkpokọta nke cellulose ether na-abawanye ma na-adabereghị na ụdị na ogo nnọchi. Ya mere, cellulose ethers nke otu ọkwa viscosity, ma MC, HPmc ma ọ bụ HEmc, na-egosipụta otu ihe ndị dị na rheological ma ọ bụrụhaala na ntinye na okpomọkụ na-adịgide. Mgbe okpomọkụ na-abawanye, a na-emepụta gel nhazi ma na-eme nnukwu thixotropic. Cellulose ethers nwere oke viscosity na obere viscosity na-egosipụta thixotropy ọbụna n'okpuru okpomọkụ gel. Ihe onwunwe a bara nnukwu uru na owuwu nke ụlọ iji gbanwee ihe onwunwe ya na-ekowe na mmiri. Ọ dị mkpa ka a kọwaa ebe a na ka viscosity nke cellulose ether dị elu, otú ahụ ka viscosity nke mmiri si adị mma, mana ka viscosity dị elu, otú ahụ ka molekul nke cellulose ether dị elu, otú ahụ ka mbelata nke mmiri si adị, nke nwere mmetụta ọjọọ na ntinye moto na arụmọrụ owuwu. Ka viscosity dị elu, otú ahụ ka mmetụta thickening nke moto si apụta ìhè, mana ọ bụghị mmekọrịta zuru oke. Ụfọdụ viscosity dị ala, mana gbanwetụrụ gbanwetụrụ na imeziwanye ike nhazi nke moto mmiri nwere arụmọrụ ka mma, ka mmụba nke viscosity na-abawanye, ka mmiri cellulose ether dị mma.
Oge ozi: Maachị-30-2022