Menene Cellulose Ether?

Cellulose etherwani mahaɗin polymer ne mai tsarin ether da aka yi da cellulose. Kowace zobe ta glucosyl a cikin macromolecule na cellulose ta ƙunshi ƙungiyoyin hydroxyl guda uku, babban rukunin hydroxyl a kan atom na carbon na shida, ƙungiyar hydroxyl ta biyu a kan atom na carbon na biyu da na uku, kuma hydrogen a cikin rukunin hydroxyl an maye gurbinsa da ƙungiyar hydrocarbon don samar da abubuwa masu alaƙa da cellulose ether. Samfuri ne wanda aka maye gurbin hydrogen na ƙungiyar hydroxyl a cikin polymer na cellulose da ƙungiyar hydrocarbon. Cellulose mahaɗin polyhydroxy polymer ne wanda ba ya narke ko narkewa. Bayan etherification, cellulose yana narkewa a cikin ruwa, yana narkewar maganin alkali da kuma sinadarin sinadarai na halitta, kuma yana da thermoplasticity.

Cellulose wani sinadari ne na polyhydroxy polymer wanda baya narkewa ko narkewa. Bayan etherification, cellulose yana narkewa a cikin ruwa, yana narkewar maganin alkali da kuma sinadarin organic solvent, kuma yana da thermoplasticity.

1. Yanayi:

Narkewar cellulose bayan etherification yana canzawa sosai. Ana iya narke shi a cikin ruwa, rage acid, rage alkaline ko kuma sinadarin organic solvent. Narkewar ya dogara ne akan abubuwa uku: (1) Halayen ƙungiyoyin da aka gabatar a cikin tsarin etherification, da aka gabatar. Girman rukuni, ƙarancin narkewa, da kuma ƙarfin polarity na rukunin da aka gabatar, da sauƙin narkewar cellulose ether a cikin ruwa; (2) Matsayin maye gurbin da rarrabawar ƙungiyoyin ethered a cikin macromolecule. Yawancin ethers na cellulose za a iya narke su ne kawai a cikin ruwa a ƙarƙashin wani matakin maye gurbin, kuma matakin maye gurbin yana tsakanin 0 da 3; (3) Matsayin polymerization na cellulose ether, mafi girman matakin polymerization, ƙarancin narkewa; Ƙananan matakin maye gurbin da za a iya narkewa a cikin ruwa, faɗin kewayon. Akwai nau'ikan ethers na cellulose da yawa waɗanda ke da kyakkyawan aiki, kuma ana amfani da su sosai a cikin gini, siminti, man fetur, abinci, yadi, sabulun wanki, fenti, magani, yin takarda da kayan lantarki da sauran masana'antu.

2. Haɓaka:

Kasar Sin ita ce babbar kasa a duniya da ke samar da kuma amfani da sinadarin cellulose ether, inda matsakaicin karuwarsa ta kai sama da kashi 20% a kowace shekara. A cewar kididdigar farko, akwai kimanin kamfanonin samar da sinadarin cellulose ether guda 50 a kasar Sin, kuma karfin samar da sinadarin cellulose ether da aka tsara ya wuce tan 400,000, kuma akwai kimanin kamfanoni 20 da ke da tan sama da 10,000, galibi ana rarraba su a Shandong, Hebei, Chongqing da Jiangsu, Zhejiang, Shanghai da sauran wurare.

3. Bukata:

A shekarar 2011, ƙarfin samar da CMC na ƙasar Sin ya kai kimanin tan 300,000. Tare da ƙaruwar buƙatar ƙwayoyin cellulose masu inganci a masana'antu kamar magunguna, abinci, da sinadarai na yau da kullun, buƙatar cikin gida ga wasu kayayyakin cellulose ether banda CMC yana ƙaruwa. , ƙarfin samar da MC/HPMC ya kai kimanin tan 120,000, kuma na HEC ya kai kimanin tan 20,000. PAC har yanzu tana cikin matakin haɓakawa da amfani a ƙasar Sin. Tare da haɓaka manyan filayen mai na ƙasashen waje da haɓaka kayan gini, abinci, sinadarai da sauran masana'antu, adadin da filin PAC yana ƙaruwa kuma yana faɗaɗa kowace shekara, tare da ƙarfin samarwa sama da tan 10,000.

4. Rarrabawa:

Dangane da tsarin sinadarai na maye gurbin, ana iya raba su zuwa anionic, cationic da nonionic ethers. Dangane da wakilin etherification da aka yi amfani da shi, akwai methyl cellulose, hydroxyethyl methyl cellulose, carboxymethyl cellulose, ethyl cellulose, benzyl cellulose, hydroxyethyl cellulose, hydroxypropyl methyl cellulose cellulose, cyanoethyl cellulose, benzyl cyanoethyl cellulose, carboxymethyl hydroxyethyl cellulose da phenyl cellulose, da sauransu. Methyl cellulose da ethyl cellulose sun fi amfani.

Methylcellulose:

Bayan an yi wa audugar da aka tace magani da alkali, ana samar da cellulose ether ta hanyar jerin halayen da methane chloride a matsayin wakilin etherification. Gabaɗaya, matakin maye gurbin shine 1.6~2.0, kuma narkewar shi ma ya bambanta da matakai daban-daban na maye gurbin. Yana cikin cellulose ether wanda ba ionic ba.

(1) Methylcellulose yana narkewa a cikin ruwan sanyi, kuma zai yi wuya a narke a cikin ruwan zafi. Maganin ruwansa yana da ƙarfi sosai a cikin kewayon pH = 3 ~ 12. Yana da kyakkyawan jituwa da sitaci, guar gum, da sauransu da yawa. Lokacin da zafin jiki ya kai zafin gelation, gelation yana faruwa.

(2) Rikewar ruwa na methyl cellulose ya dogara da adadin ƙarinsa, danko, girman barbashi da kuma yawan narkewar sa. Gabaɗaya, idan adadin ƙarin ya yi yawa, dankoshi ƙarami ne, kuma dankoshi babba ne, adadin riƙe ruwa yana da yawa. Daga cikinsu, adadin ƙarin yana da babban tasiri akan yawan riƙe ruwa, kuma matakin dankoshi ba ya daidai da matakin riƙe ruwa kai tsaye. Yawan narkewar ya dogara ne akan matakin gyaran saman barbashi na cellulose da dankoshi. Daga cikin ƙwayoyin cellulose da ke sama, methyl cellulose da hydroxypropyl methyl cellulose suna da ƙarin yawan riƙe ruwa.

(3) Canje-canje a yanayin zafi na iya yin tasiri sosai ga riƙewar methyl cellulose a cikin ruwa. Gabaɗaya, idan yawan zafin ya yi yawa, to, riƙewar ruwa ta yi muni. Idan zafin turmi ya wuce 40°C, riƙewar methyl cellulose a cikin ruwa zai ragu sosai, wanda hakan zai shafi ginin turmi sosai.

(4)Methyl celluloseyana da tasiri mai mahimmanci akan iya aiki da haɗin turmi. "Mannewa" a nan yana nufin ƙarfin haɗin da aka ji tsakanin kayan aikin mai amfani da ma'aikacin da kuma abin da ke kan bango, wato, juriyar yanke turmi. Mannewa yana da girma, juriyar yanke turmi yana da girma, kuma ƙarfin da ma'aikata ke buƙata yayin amfani shi ma yana da girma, kuma aikin ginin turmi ba shi da kyau. Haɗin methyl cellulose yana da matsakaicin matsayi a cikin samfuran cellulose ether.

Hydroxypropylmethylcellulose:

Hydroxypropyl methylcellulose nau'in cellulose ne wanda fitarwa da amfaninsa ke ƙaruwa cikin sauri. Yana da gaurayen ether ne wanda ba ionic ba wanda aka yi daga auduga mai tsafta bayan alkali, ta amfani da propylene oxide da methyl chloride a matsayin wakilin etherification, ta hanyar jerin halayen. Matsayin maye gurbin gabaɗaya shine 1.2~2.0. Halayensa sun bambanta dangane da rabon abun ciki na methoxyl da abun ciki na hydroxypropyl.

(1) Hydroxypropyl methylcellulose yana narkewa cikin sauƙi a cikin ruwan sanyi, kuma zai fuskanci matsaloli wajen narkewa a cikin ruwan zafi. Amma zafin gelation ɗinsa a cikin ruwan zafi ya fi na methyl cellulose girma sosai. Hakanan yana inganta narkewa a cikin ruwan sanyi sosai idan aka kwatanta da methyl cellulose.

(2) Dankowar hydroxypropyl methylcellulose tana da alaƙa da nauyin kwayoyin halittarta, kuma girman nauyin kwayoyin halittar, haka nan girman dankowar. Zafin jiki kuma yana shafar dankowarta, yayin da zafin jiki ke ƙaruwa, dankowar yana raguwa. Duk da haka, tasirin dankowarta da zafin jikinta ya yi ƙasa da na methyl cellulose. Maganinta yana da ƙarfi idan aka adana shi a zafin jiki na ɗaki.

(3) Rikewar ruwa na hydroxypropyl methylcellulose ya dogara da adadin ƙarinsa, dankonsa, da sauransu, kuma yawan riƙewar ruwa a ƙarƙashin adadin ƙarin ya fi na methyl cellulose girma.

(4)Hydroxypropyl methylcelluloseyana da daidaito ga acid da alkali, kuma ruwan da yake sha yana da daidaito sosai a cikin kewayon pH = 2 ~ 12. Soda mai kauri da ruwan lemun tsami ba su da tasiri sosai kan aikinsu, amma alkali na iya hanzarta narkewar sa kuma ya ƙara ɗan ɗanɗanonsa. Hydroxypropyl methylcellulose yana da daidaito ga gishirin da aka saba da shi, amma idan yawan ruwan gishiri ya yi yawa, ɗanɗano na ruwan hydroxypropyl methylcellulose yana ƙaruwa.

(5) Ana iya haɗa Hydroxypropyl methylcellulose da mahaɗan polymer masu narkewa cikin ruwa don samar da mafita mai kama da juna kuma mafi girma. Kamar polyvinyl alcohol, sitaci ether, kayan lambu, da sauransu.

(6) Hydroxypropyl methylcellulose yana da juriya ga enzyme fiye da methylcellulose, kuma maganin sa ba shi da yuwuwar lalacewa ta hanyar enzymes fiye da methylcellulose.

(7) Mannewar hydroxypropyl methylcellulose ga ginin turmi ya fi na methylcellulose girma.

Cellulose na Hydroxyethyl:

An yi shi ne da auduga mai kyau da aka yi wa magani da alkali, kuma ana yin sa da ethylene oxide a matsayin maganin etherification idan aka haɗa shi da isopropanol. Matsakaicin maye gurbinsa gabaɗaya shine 1.5 ~ 2.0. Yana da ƙarfi sosai kuma yana da sauƙin sha danshi.

(1) Hydroxyethyl cellulose yana narkewa a cikin ruwan sanyi, amma yana da wuya a narke a cikin ruwan zafi. Maganin sa yana da ƙarfi a zafin jiki mai yawa ba tare da gel ba. Ana iya amfani da shi na dogon lokaci a cikin zafin jiki mai yawa a cikin turmi, amma riƙewar ruwansa ya yi ƙasa da na methyl cellulose.

(2) Hydroxyethyl cellulose yana da daidaito ga acid da alkali gabaɗaya, kuma alkali na iya hanzarta narkewarsa da kuma ƙara ɗanɗanonsa kaɗan. Watsuwar sa a cikin ruwa ya ɗan fi muni fiye da na methyl cellulose da hydroxypropyl methyl cellulose.

(3) Hydroxyethyl cellulose yana da kyakkyawan aikin hana sag ga turmi, amma yana da tsawon lokacin jinkirin siminti.

(4) Ayyukan hydroxyethyl cellulose da wasu kamfanonin cikin gida ke samarwa a bayyane yake ƙasa da na methyl cellulose saboda yawan ruwa da kuma yawan toka da ke cikinsa.

(5) Ruwan da ke cikin ruwan maganin hydroxyethyl cellulose yana da matuƙar illa. A yanayin zafi na kimanin 40°C, ruwan da ke cikinsa na iya faruwa cikin kwana 3 zuwa 5, wanda hakan zai shafi aikinsa.

Carboxymethyl cellulose:

Ana yin Lonic cellulose ether daga zare na halitta (auduga, da sauransu) bayan an yi maganin alkali, ana amfani da sodium monochloroacetate a matsayin wakilin etherification, kuma ana yin jerin jiyya. Matsakaicin maye gurbin gabaɗaya shine 0.4 ~ 1.4, kuma aikin sa yana da tasiri sosai ta hanyar matakin maye gurbin.

(1) Carboxymethyl cellulose yana da hygroscopic sosai, kuma zai ƙunshi ƙarin ruwa idan aka adana shi a ƙarƙashin yanayi na yau da kullun.

(2) Ruwan da ke cikin ruwa na Carboxymethyl cellulose baya samar da gel, kuma danko yana raguwa tare da karuwar zafin jiki. Idan zafin ya wuce 50°C, danko ba zai iya canzawa ba.

(3) Matsayin pH yana da matuƙar tasiri ga kwanciyar hankalinsa. Gabaɗaya, ana iya amfani da shi a turmi mai tushen gypsum, amma ba a cikin turmi mai tushen siminti ba. Idan yana da alkaline sosai, zai rasa ɗanko.

(4) Rikewar ruwa da ke cikinsa ya yi ƙasa da methyl cellulose. Yana da tasiri mai hana ruwa gudu akan turmi da aka yi da gypsum kuma yana rage ƙarfinsa. Duk da haka, farashin carboxymethyl cellulose ya yi ƙasa sosai fiye da na methyl cellulose.

Cellulose Alkyl Ether:

Waɗanda suka fi shahara sune methyl cellulose da ethyl cellulose. A fannin samar da kayayyaki, galibi ana amfani da methyl chloride ko ethyl chloride a matsayin wakilin etherification, kuma martanin shine kamar haka:

A cikin dabarar, R yana wakiltar CH3 ko C2H5. Yawan alkaline ba wai kawai yana shafar matakin etherification ba, har ma yana shafar yawan alkyl halides. Rage yawan alkali, haka nan yake ƙara ƙarfin hydrolysis na alkyl halide. Domin rage yawan amfani da etherifying agent, dole ne a ƙara yawan alkali. Duk da haka, lokacin da yawan alkali ya yi yawa, tasirin kumburi na cellulose yana raguwa, wanda ba ya da amfani ga amsawar etherification, kuma saboda haka matakin etherification yana raguwa. Don wannan dalili, ana iya ƙara lye mai ƙarfi ko lye mai ƙarfi yayin amsawar. Ya kamata reactor ɗin ya sami na'urar motsawa da tsagewa mai kyau don a iya rarraba alkali daidai gwargwado. Ana amfani da Methyl cellulose sosai a matsayin mai kauri, mannewa da kariya daga colloid da sauransu. Haka kuma ana iya amfani da shi azaman mai warwatsewa don polymerization na emulsion, mai warwatsewa don iri, slurry na yadi, ƙari don abinci da kayan kwalliya, manne na likitanci, kayan shafa magani, kuma ana amfani da shi a fenti na latex, tawada na bugawa, samar da yumbu, kuma a gauraya shi cikin siminti. Ana amfani da shi don sarrafa lokacin saitawa da ƙara ƙarfin farko, da sauransu. Kayayyakin ethyl cellulose suna da ƙarfin injina mai ƙarfi, sassauci, juriyar zafi da juriyar sanyi. ethyl cellulose mai ƙarancin maye gurbin yana narkewa a cikin ruwa kuma yana narkewa a cikin ruwan alkaline, kuma samfuran da aka maye gurbinsu da yawa suna narkewa a cikin yawancin abubuwan narkewa na halitta. Yana da kyakkyawan jituwa tare da resins da masu plasticizers daban-daban. Ana iya amfani da shi don yin robobi, fina-finai, varnishes, manne, latex da kayan shafa don magunguna, da sauransu. Gabatar da ƙungiyoyin hydroxyalkyl cikin cellulose alkyl ethers na iya inganta narkewar sa, rage saurin fitar da gishiri, ƙara zafin gelation da inganta halayen narkewar zafi, da sauransu. Matsayin canji a cikin kaddarorin da ke sama ya bambanta dangane da yanayin abubuwan maye da rabon ƙungiyoyin alkyl zuwa hydroxyalkyl.

Cellulose Hydroxyalkyl Ether:

Waɗanda suka fi shahara sune hydroxyethyl cellulose da hydroxypropyl cellulose. Abubuwan da ke haifar da etherifying sune epoxides kamar ethylene oxide da propylene oxide. Yi amfani da acid ko tushe a matsayin mai kara kuzari. Ana samar da masana'antu ne don yin maganin alkali cellulose tare da wakilin etherification:hydroxyethyl cellulosetare da babban darajar maye gurbin yana narkewa a cikin ruwan sanyi da ruwan zafi. Hydroxypropyl cellulose mai babban darajar maye gurbin yana narkewa ne kawai a cikin ruwan sanyi amma ba a cikin ruwan zafi ba. Ana iya amfani da Hydroxyethyl cellulose azaman mai kauri don shafa latex, buga yadi da manna rini, kayan girman takarda, manne da colloids masu kariya. Amfani da hydroxypropyl cellulose yayi kama da na hydroxyethyl cellulose. Hydroxypropyl cellulose mai ƙarancin darajar maye gurbin za a iya amfani da shi azaman abin da ke taimakawa wajen samar da magunguna, wanda zai iya samun kaddarorin ɗaurewa da na wargajewa.

Carboxymethyl cellulose, wato taƙaitaccen bayani na Turanci CMC, galibi yana wanzuwa a cikin nau'in gishirin sodium. Maganin etherifying shine monochloroacetic acid, kuma amsawar shine kamar haka:

Carboxymethyl cellulose ita ce cellulose ether da aka fi amfani da ita wajen narkewar ruwa. A da, galibi ana amfani da ita ne a matsayin laka mai haƙa rami, amma yanzu an faɗaɗa ta don a yi amfani da ita a matsayin ƙarin sabulun wanki, abin rufe fuska na tufafi, fenti na latex, shafi na kwali da takarda, da sauransu. Ana iya amfani da cellulose carboxymethyl a abinci, magani, kayan kwalliya, da kuma a matsayin manne ga yumbu da mold.

Polyanionic cellulose (PAC) wani nau'in ionic cellulose ether ne kuma samfurin maye gurbin carboxymethyl cellulose (CMC) ne mai ƙarfi. Fari ne, fari ko ɗan rawaya, foda ko granule, ba shi da guba, ba shi da ɗanɗano, mai sauƙin narkewa a cikin ruwa don samar da mafita mai haske tare da ɗanɗano, yana da ingantaccen kwanciyar hankali na juriya ga zafi da juriya ga gishiri, da kuma ƙarfin kaddarorin ƙwayoyin cuta. Ba shi da mildew da lalacewa. Yana da halaye na tsarki mai yawa, babban matakin maye gurbin, da rarrabawa iri ɗaya na abubuwan maye. Ana iya amfani da shi azaman mai ɗaurewa, mai kauri, mai gyara rheology, mai rage asarar ruwa, mai daidaita dakatarwa, da sauransu. Polyanionic cellulose (PAC) ana amfani da shi sosai a duk masana'antu inda za a iya amfani da CMC, wanda zai iya rage yawan amfani sosai, sauƙaƙe amfani, samar da kwanciyar hankali mafi kyau da kuma biyan buƙatun tsari mafi girma.

Cyanoethyl cellulose samfurin amsawar cellulose da acrylonitrile ne a ƙarƙashin tasirin alkali.

Cyanoethyl cellulose yana da babban dielectric constant kuma yana da ƙarancin asara kuma ana iya amfani da shi azaman resin matrix don fitilun phosphor da electroluminescent. Ana iya amfani da cyanoethyl cellulose mai ƙarancin maye gurbinsa azaman takarda mai rufi ga transformers.

An shirya ethers masu yawan kitse, alkenyl ethers, da ethers masu ƙamshi na cellulose, amma ba a yi amfani da su a aikace ba.

Ana iya raba hanyoyin shirya cellulose ether zuwa hanyoyin ruwa, hanyoyin narkewa, hanyoyin murƙushewa, hanyoyin slurry, hanyoyin iskar gas, hanyoyin ruwa da haɗin hanyoyin da ke sama.

5. Ka'idar shiri:

Ana jiƙa ɓangaren litattafan α-cellulose mai yawan sinadarin alkaline don ya kumbura shi don lalata ƙarin haɗin hydrogen, sauƙaƙe yaɗuwar reagents da samar da alkali cellulose, sannan a yi aiki da wakilin etherification don samun cellulose ether. Abubuwan da ke haifar da ether sun haɗa da hydrocarbon halides (ko sulfates), epoxides, da α da β unsaturated compounds tare da masu karɓar electron.

6. Aiki na asali:

Sinadaran suna taka muhimmiyar rawa wajen inganta aikin gina turmi mai gauraya busasshe, kuma suna da sama da kashi 40% na farashin kayan da ake amfani da su a turmi mai gauraya busasshe. Masana'antun ƙasashen waje ne ke samar da wani babban ɓangare na sinadarin a cikin kasuwar cikin gida, kuma mai samar da shi ma yana samar da ma'aunin da ake buƙata na samfurin. Sakamakon haka, farashin kayayyakin turmi mai gauraya busasshe har yanzu yana da yawa, kuma yana da wuya a yaɗa turmi mai gauraya da siminti na yau da kullun tare da adadi mai yawa da kuma nau'ikan da yawa. Kamfanonin ƙasashen waje ne ke sarrafa kayayyakin kasuwa masu tsada, kuma masana'antun turmi mai gauraya busasshe suna da ƙarancin riba da ƙarancin araha; aikace-aikacen sinadaran ba shi da bincike mai tsari da manufa, kuma yana bin dabarun ƙasashen waje a makance.

Maganin riƙe ruwa muhimmin abu ne da ake amfani da shi wajen inganta aikin riƙe ruwa na turmi mai gauraye da busasshe, kuma yana ɗaya daga cikin mahimman kayan haɗin don tantance farashin kayan turmi mai gauraye da busasshe. Babban aikin cellulose ether shine riƙe ruwa.

Cellulose ether kalma ce ta gabaɗaya ga jerin samfuran da aka samar ta hanyar amsawar alkali cellulose da wakilin etherifying a ƙarƙashin wasu yanayi. Ana maye gurbin Alkali cellulose da wakilai daban-daban na etherifying don samun ethers cellulose daban-daban. Dangane da halayen ionization na masu maye gurbin, ana iya raba ethers cellulose zuwa rukuni biyu: ionic (kamar carboxymethyl cellulose) da nonionic (kamar methyl cellulose). Dangane da nau'in maye gurbin, ana iya raba cellulose ether zuwa monoether (kamar methyl cellulose) da gauraye ether (kamar hydroxypropyl methyl cellulose). Dangane da narkewa daban-daban, ana iya raba shi zuwa narkewa na ruwa (kamar hydroxyethyl cellulose) da narkewa na Organic (kamar ethyl cellulose). Turmi mai gauraya busasshe galibi shine cellulose mai narkewa cikin ruwa, kuma cellulose mai narkewa cikin ruwa an raba shi zuwa nau'in nan take da nau'in narkewa da aka yi wa magani a saman.

Tsarin aikin cellulose ether a cikin turmi shine kamar haka:

(1) Bayan kammala karatuncellulose etherA cikin turmi da aka narkar da shi a cikin ruwa, ana tabbatar da ingantaccen rarraba kayan siminti a cikin tsarin saboda aikin saman, kuma cellulose ether, a matsayin colloid mai kariya, yana "naɗe" ƙwayoyin da ke da ƙarfi kuma an samar da wani Layer na fim mai shafawa a saman waje, wanda ke sa tsarin turmi ya fi karko, kuma yana inganta ruwan turmi yayin aikin haɗawa da santsi na gini.

(2) Saboda tsarin kwayoyin halittarsa, ruwan cellulose ether yana sa danshi a cikin turmi ba shi da sauƙin rasawa, kuma a hankali yana sake shi tsawon lokaci, yana ba turmi damar riƙe ruwa da aiki mai kyau.