Focus on Cellulose ethers

Hydroxypropyl Methyl Cellulose Ibiranga HPMC

Hydroxypropyl methylcellulose HPMC ni ubwoko bwa selile idafite ionic ivanze na ether. Bitandukanye na ionic methyl carboxymethyl selulose ivanze na ether, ntabwo ikora hamwe nibyuma biremereye. Bitewe numubare utandukanye wibintu bya vitamine hamwe nibirimo hydroxypropyl muri hydroxypropyl methylcellulose hamwe na viscosities zitandukanye, hariho ubwoko bwinshi bufite imitungo itandukanye, kurugero, vitamine nyinshi hamwe nibirimo hydroxypropyl nkeya Imikorere yayo yegereye iya methyl selulose, mugihe imikorere ya ibirimo bike bya hydroxy na hydroxypropyl biri hafi ya hydroxypropyl methyl selulose. Nyamara, muri buri bwoko, nubwo umubare muto wa hydroxypropyl cyangwa itsinda rito rya metoxyl urimo, ibishishwa mumashanyarazi cyangwa ubushyuhe bwa flocculation mubisubizo byamazi biratandukanye cyane.
 
1. Ubushobozi bwa hydroxypropyl methylcellulose
Ububasha bwa hydroxypropyl methylcellulose mumazi Hydroxypropyl methylcellulose mubyukuri ni ubwoko bwa methylcellulose yahinduwe na okiside ya propylene (mitoxypropylene), bityo iracyafite imitungo imwe na methyl selulose Cellulose ifite ibintu bisa biranga amazi akonje hamwe nubushyuhe bwamazi ashyushye. Nyamara, bitewe na hydroxypropyl yahinduwe, ubushyuhe bwayo bwo mumazi ashyushye burenze kure ubwa methyl selile. Kurugero, ubwiza bwa hydroxypropyl methylcellulose yumuti wamazi hamwe na 2% ya metxyxy yo gusimbuza DS = 0,73 hamwe na hydroxypropyl ibirimo MS = 0.46 nigicuruzwa cya 500 mpa? S kuri 20 ° C, nubushyuhe bwa gel burashobora kugera kuri 100 ° C, mugihe methyl selulose ku bushyuhe bumwe ni 55 ° C. Kubijyanye no gusesa mumazi, nayo yaratejwe imbere cyane. Kurugero, hydroxypropyl methylcellulose ya pulverized (igicuruzwa gifite ubunini bwa 0.2 ~ 0.5mm hamwe na 4% yumuti wamazi wa 2pa? S kuri 20 ° C urashobora kugurwa Kubushyuhe bwicyumba, byoroshye gushonga mumazi udakonje .
 
Ububasha bwa hydroxypropyl methylcellulose mumashanyarazi ya organic Solubile ya hydroxypropyl methylcellulose mumashanyarazi kama nayo iruta iya methylcellulose. Kubicuruzwa biri hejuru ya 2.1,hydroxypropyl methylcelluloseirimo hydroxypropyl MS = 1.5 ~ 1.8 na mikorerexy DS = 0.2 ~ 1.0, hamwe nurwego rwose rwo gusimbuza hejuru ya 1.8, irashonga muri methyol anhydrous methanol na Ethanol ibisubizo Medium, hamwe na thermoplastique hamwe n-amazi. Irashobora kandi gushonga muri hydrocarbone ya chlorine nka methylene chloride na chloroform, hamwe na solge organic nka acetone, isopropanol na alcool ya diacetone. Gukemura kwayo mumashanyarazi kama nibyiza kuruta amazi.
 
2. Ibintu bigira ingaruka ku bwiza bwa hydroxypropyl methylcellulose
Ibintu bigira ingaruka kuri Viscosity ya Hydroxypropyl Methyl Cellulose Igenamiterere risanzwe rya viscosity ya hydroxypropyl methyl selulose ni kimwe nizindi eteri ya selile. Ipimwa kuri 20 ° C hamwe na 2% yumuti wamazi nkibisanzwe. Ubukonje bwibicuruzwa bimwe byiyongera hamwe no kwiyongera kwibitekerezo. Kubicuruzwa bifite uburemere butandukanye bwa molekuline kumurongo umwe, ibicuruzwa bifite uburemere bunini bwa molekile bifite ubwiza bwinshi. Isano yayo nubushyuhe isa nubwa methyl selulose. Iyo ubushyuhe buzamutse, ibishishwa bitangira kugabanuka, ariko iyo bigeze ku bushyuhe runaka, ubukonje burazamuka butunguranye kandi gelation iba. Ubushyuhe bwa gel bwibicuruzwa biri hasi cyane. ni hejuru. Ingingo ya gel yayo ntabwo ifitanye isano gusa nubwiza bwa ether gusa, ahubwo ifitanye isano nigipimo cyimiterere yitsinda rya mikorerexyl hamwe na hydroxypropyl groupe muri ether nubunini bwurwego rusimburwa. Twabibutsa ko hydroxypropyl methylcellulose nayo ari pseudoplastique, kandi igisubizo cyacyo kikaba gihamye mubushyuhe bwicyumba nta kwangirika kwijimye usibye ko hashobora kubaho kwangirika kwimisemburo.
 
3. Hydroxypropyl methylcellulose irwanya aside na alkali
Hydroxypropyl methylcellulose aside hamwe na alkali irwanya Hydroxypropyl methylcellulose muri rusange ihagaze neza kuri acide na alkalis, kandi ntabwo igira ingaruka mubipimo bya pH 2 ~ 12. Irashobora kwihanganira urugero runaka rwa acide yumucyo, nka acide formique, acide acike, acide citric, acide succinic, aside fosifori, aside boric, nibindi. Ariko aside yibanze ifite ingaruka zo kugabanya ubukonje. Alkalis nka soda ya caustic, potas ya caustic n'amazi ya lime nta ngaruka bigira kuri yo, ariko birashobora kongera ubworoherane bwumuti wumuti, hanyuma bikagabanuka buhoro buhoro.
 
4. Kubeshya hydroxypropyl methylcellulose
Ikibazo cya hydroxypropyl methylcellulose Hydroxypropyl methylcellulose igisubizo gishobora kuvangwa namazi ya elegitoronike ya polymer kugirango ibe igisubizo kimwe kandi kiboneye hamwe nubwiza bwinshi. Ibi bikoresho bya polymer birimo polyethylene glycol, acetate ya polyvinyl, polysilicone, polymethylvinylsiloxane, hydroxyethyl selulose, na methyl selulose. Ibintu bisanzwe bya molekuliyumu nka gum arabic, inzige ibishyimbo, karaya gum, nibindi nabyo bihuza neza nigisubizo cyacyo. Hydroxypropyl methylcellulose irashobora kandi kuvangwa na ester ya mannitol cyangwa sorbitol ester ya acide stearic cyangwa aside palmitike, kandi ishobora no kuvangwa na glycerine, sorbitol na mannitol, kandi ibyo bikoresho bishobora gukoreshwa nka hydroxypropyl methylcellulose Plasticizer ya selile.
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5. Insolubilisation hamwe no gukemura amazi ya hydroxypropyl methylcellulose
Amazi adashonga ya selile yamashanyarazi ya hydroxypropyl methylcellulose arashobora guhuzwa na aldehydes hejuru, kugirango ethers zishonga mumazi zigwa mumuti hanyuma zigahinduka amazi. Aldehydes ituma hydroxypropyl methylcellulose idashobora gushonga harimo formehide, glyoxal, succinic aldehyde, adipaldehyde, nibindi. umukozi mu musaruro winganda. Umubare wubwoko nkubu bwo guhuza ibikorwa mubisubizo ni 0.2% ~ 10% bya misa ya ether, nibyiza 7% ~ 10%, kurugero, 3.3% ~ 6% ya glyoxal niyo ikwiye cyane. Ubushyuhe rusange bwo kuvura ni 0 ~ 30 ℃, kandi igihe ni 1 ~ 120min. Igikorwa cyo guhuza ibikorwa kigomba gukorwa mugihe cya acide. Mubisanzwe, igisubizo kibanza kongerwamo aside irike idasanzwe cyangwa acide karubasi ya karubike kugirango ihindure pH yumuti kuri 2 ~ 6, byaba byiza hagati ya 4 ~ 6, hanyuma ukongeramo aldehydes kugirango ukore reaction ihuza. Acide yakoreshejwe ifite aside hydrochloric, aside sulfurike, aside fosifori, aside aside, aside acike, aside hydroxyacetic aside, acide succinic cyangwa aside citric nibindi, aho usanga inama ya acide formique cyangwa acide acike, kandi aside irike nibyiza. Acide na aldehyde birashobora kandi kongerwaho icyarimwe kugirango byemere igisubizo kunyuranya-reaction ihuza pH yifuza. Iyi reaction ikoreshwa kenshi muburyo bwa nyuma bwo kuvura mugutegura selile ya selile. Ether ya selulose imaze kudashonga, biroroshye koza no kweza amazi kuri 20 ~ 25 ° C. Iyo ibicuruzwa biri gukoreshwa, ibintu bya alkaline birashobora kongerwaho igisubizo cyibicuruzwa kugirango uhindure pH yumuti kugirango ube alkaline, kandi ibicuruzwa bizashonga mubisubizo byihuse. Ubu buryo burakoreshwa no kuvura firime nyuma yumuti wa selulose ether ikozwe muri firime kugirango ikore firime idashonga.
 
6. Enzyme irwanya hydroxypropyl methylcellulose
Enzyme irwanya hydroxypropyl methylcellulose ninkomoko ya selile ikomoka kuri selile, nka buri tsinda rya anhydroglucose, niba hari itsinda risimburana, ntabwo byoroshye kwanduzwa na mikorobe, ariko mubyukuri ibicuruzwa byarangiye Iyo agaciro kayasimbuye karenze 1, iba bizanateshwa agaciro na enzymes, bivuze ko urwego rwo gusimbuza buri tsinda kumurongo wa selile ridahuje bihagije, kandi mikorobe irashobora kwangirika kumatsinda ya anhydroglucose idafite ishingiro kugirango ibe isukari, nkintungamubiri za mikorobe zinjira. Kubwibyo, niba urwego rwo gusimbuza etherification ya selile yiyongereye, kurwanya isuri yimisemburo ya selile ya ether nayo iziyongera. Nk’uko raporo zibyerekana, mu gihe cyagenzuwe, ibisubizo bya hydrolysis biva mu misemburo, ubukonje busigaye bwa hydroxypropyl methylcellulose (DS = 1.9) ni 13.2%, methylcellulose (DS = 1.83) ni 7.3%, methylcellulose (DS = 1.66) ni 3.8%, hydroxyethyl selulose ni 1.7%. Birashobora kugaragara ko hydroxypropyl methylcellulose ifite ubushobozi bukomeye bwo kurwanya enzyme. Kubwibyo, enzyme nziza irwanya hydroxypropyl methylcellulose, ifatanije nogutandukana kwayo neza, kubyimba no gukora firime, ikoreshwa mubitambaro byamazi-emuliyoni, nibindi, kandi mubisanzwe ntabwo ikeneye kongeramo imiti igabanya ubukana. Ariko, kububiko bwigihe kirekire bwibisubizo cyangwa ibishoboka byanduye bivuye hanze, imiti igabanya ubukana irashobora kongerwaho muburyo bwo kwirinda, kandi guhitamo birashobora kugenwa ukurikije ibisabwa bya nyuma byigisubizo. Fenilmercuric acetate na fluorosilicate ya manganese birinda ibintu neza, ariko byose bifite Uburozi, bigomba kwitabwaho kubikorwa. Mubisanzwe, 1 ~ 5mg ya acetate ya fenylmercury irashobora kongerwaho igisubizo kuri litiro ya dosiye.
 
7. Imikorere ya hydroxypropyl methylcellulose membrane
Imikorere ya hydroxypropyl methylcellulose firime Hydroxypropyl methylcellulose ifite imiterere myiza yo gukora film. Umuti wacyo wamazi cyangwa igisubizo kama kama gishyizwe kumasahani yikirahure, kandi gihinduka ibara kandi kibonerana nyuma yo gukama. Kandi firime ikomeye. Ifite ubushyuhe bwiza kandi ikomeza gukomera ku bushyuhe bwinshi. Niba hiyongereyeho plasitiki ya hygroscopique, kurambura no guhinduka birashobora kwiyongera. Mu rwego rwo kunoza imiterere, plasitike nka glycerine na sorbitol nibyo byiza cyane. Mubisanzwe, ibisubizo byibisubizo ni 2% ~ 3%, naho plastiseri ni 10% ~ 20% ya selile ya ether. Niba ibirimo plasitike ari byinshi, kugabanuka kwa colloidal dehydrasiyo bizabaho mubushuhe bwinshi. Imbaraga zingana za firime zongewemo na plasitiki nini cyane kuruta iyo utongeyeho, kandi yiyongera hamwe no kwiyongera kwamafaranga yiyongereye, kandi hygroscopicity ya firime nayo iriyongera hamwe no kwiyongera kwa plastike


Igihe cyo kohereza: Ukuboza-19-2022
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