Kwangirika k'ubushyuhe bwa hydroxypropyl methylcellulose ni iki?

Hydroxypropyl methylcellulose (HPMC) ni ether ya ionic selulose ether ikoreshwa cyane mubuvuzi, ibiryo, ubwubatsi nizindi nzego, cyane cyane mubiyobyabwenge bikomeza kurekura hamwe nibikoresho byubaka. Ubushakashatsi bwo kwangirika k'ubushyuhe bwa HPMC ntabwo ari ingenzi gusa mu gusobanukirwa impinduka zikorwa zishobora guhura nazo mugihe cyo gutunganya, ariko kandi zifite akamaro kanini mugutezimbere ibikoresho bishya no kuzamura ubuzima bwa serivisi n'umutekano wibicuruzwa.

Ibiranga ubushyuhe bwa HPMC

Kwangirika k'ubushyuhe bwa hydroxypropyl methylcellulose byibasiwe ahanini n'imiterere ya molekile, ubushyuhe n'ubushyuhe bw’ibidukikije (nk'ikirere, ubushuhe, n'ibindi). Imiterere ya molekile yayo irimo umubare munini wamatsinda ya hydroxyl hamwe na ether, bityo ikunze guhura nubushakashatsi bwimiti nka okiside no kubora mubushyuhe bwinshi.

Uburyo bwo gutakaza ubushyuhe bwa HPMC busanzwe bugabanijwe mubice byinshi. Ubwa mbere, ku bushyuhe bwo hasi (hafi 50-150 ° C), HPMC irashobora gutakaza igihombo kinini kubera gutakaza amazi yubusa n’amazi yamamajwe, ariko iki gikorwa ntikirimo gucamo imiti, gusa impinduka zumubiri. Mugihe ubushyuhe buzamutse cyane (hejuru ya 150 ° C), imigozi ya ether hamwe nitsinda rya hydroxyl mumiterere ya HPMC bitangira gucika, bikaviramo gucika urunigi rwa molekile no guhinduka muburyo. By'umwihariko, iyo HPMC ishyutswe kugeza kuri 200-300 ° C, itangira kwangirika k'ubushyuhe, icyo gihe amatsinda ya hydroxyl n'iminyururu y'uruhande nka mikorerexy cyangwa hydroxypropyl muri molekile bigenda byangirika buhoro buhoro kugira ngo bitange umusaruro muto wa molekile nka methanol, formic aside hamwe na hydrocarbone nkeya.

Uburyo bwo guta ubushyuhe

Uburyo bwo gutakaza ubushyuhe bwa HPMC buragoye kandi burimo intambwe nyinshi. Uburyo bwayo bwo kwangirika bushobora kuvugwa muri make kuburyo bukurikira: uko ubushyuhe buzamuka, imigozi ya ether muri HPMC igenda icika buhoro buhoro kugirango itange uduce duto duto duto, hanyuma ikangirika kugirango irekure ibicuruzwa bya gaze nkamazi, dioxyde de carbone, na monoxyde de carbone. Inzira nyamukuru yubushyuhe bwo gutesha agaciro harimo intambwe zikurikira:

Uburyo bwo kubura umwuma: HPMC itakaza amazi yamamajwe kumubiri hamwe namazi make yaboshye kubushyuhe buke, kandi iyi nzira ntabwo isenya imiterere yimiti.

Gutesha agaciro amatsinda ya hydroxyl: Mu bushyuhe buri hagati ya 200-300 ° C, amatsinda ya hydroxyl kumurongo wa molekile ya HPMC atangira pyrolyze, akabyara amazi na hydroxyl radicals. Muri iki gihe, iminyururu ya hydroxypropyl na hydroxypropyl nayo igenda ibora buhoro buhoro kugirango habeho molekile nto nka methanol, aside aside, nibindi.

Kumeneka kw'uruhererekane: Iyo ubushyuhe bwongeye kwiyongera kugeza kuri 300-400 ° C, β-1,4-glycosidique ihuza urunigi runini rwa selile izanyura pyrolysis kugirango itange ibicuruzwa bito bihindagurika hamwe n’ibisigazwa bya karubone.

Ibindi byacika: Iyo ubushyuhe buzamutse hejuru ya 400 ° C, hydrocarbone isigaye hamwe na selile ya selile yangiritse bituzuye bizakomeza gucika kugirango bibyare CO2, CO nibindi bintu bito bito bya molekile.

Ibintu bigira ingaruka kumyuka mibi

Kwangirika k'ubushyuhe bwa HPMC bigira ingaruka ku bintu byinshi, cyane cyane harimo ibi bikurikira:

Ubushyuhe: Igipimo n'urwego rwo kwangirika k'ubushyuhe bifitanye isano rya bugufi n'ubushyuhe. Mubisanzwe, uko ubushyuhe buri hejuru, niko kwihuta kwifata no kurwego rwo kwangirika. Mubikorwa bifatika, uburyo bwo kugenzura ubushyuhe bwo gutunganya kugirango wirinde kwangirika kwinshi kwa HPMC nikibazo gikeneye kwitabwaho.

Ikirere: Imyitwarire yo gutakaza ubushyuhe bwa HPMC mu kirere gitandukanye nayo iratandukanye. Mu kirere cyangwa umwuka wa ogisijeni, HPMC iroroshye okiside, itanga ibicuruzwa byinshi bya gaze hamwe n’ibisigazwa bya karubone, mu gihe mu kirere kitagira ingano (nka azote), inzira yo kwangirika igaragara cyane nka pyrolysis, ikabyara ibisigisigi bike bya karubone.

Uburemere bwa molekuline: Uburemere bwa molekile ya HPMC nabwo bugira ingaruka kumyitwarire yubushyuhe bwumuriro. Uburemere buke bwa molekile, niko ubushyuhe bwo gutangira ubushyuhe bwangirika. Ni ukubera ko uburemere buke bwa molekile HPMC ifite iminyururu miremire miremire hamwe nuburyo buhamye, kandi bisaba imbaraga nyinshi zo guca imitsi ya molekile.

Ibirungo: Ibirungo biri muri HPMC nabyo bigira ingaruka kumyuka yubushyuhe. Ubushuhe burashobora kugabanya ubushyuhe bwabwo, bigatuma kwangirika kugaragara kubushyuhe buke.

Ingaruka zo gukoreshwa no gutakaza ubushyuhe

Ibiranga ubushyuhe bwa HPMC bigira ingaruka zikomeye mubikorwa byayo. Kurugero, mugutegura imiti, HPMC ikoreshwa nkibikoresho bikomeza kurekurwa kugirango igabanye igipimo cyo gusohora ibiyobyabwenge. Nyamara, mugihe cyo gutunganya ibiyobyabwenge, ubushyuhe bwinshi buzagira ingaruka kumiterere ya HPMC, bityo bihindure imikorere yo kurekura ibiyobyabwenge. Kubwibyo, kwiga imyitwarire yubushyuhe bwumuriro ningirakamaro cyane mugutezimbere gutunganya ibiyobyabwenge no kurinda ibiyobyabwenge.

Mu bikoresho byo kubaka, HPMC ikoreshwa cyane cyane mu kubaka ibicuruzwa nka sima na gypsumu kugira uruhare mu kubyimba no kubika amazi. Kubera ko ibikoresho byubaka bikenera guhura nubushyuhe bwo hejuru iyo bishyizwe mubikorwa, ubushyuhe bwumuriro wa HPMC nabwo ni ikintu cyingenzi cyo guhitamo ibikoresho. Ku bushyuhe bwinshi, kwangirika kwubushyuhe bwa HPMC bizatuma kugabanuka kwimikorere yibintu, iyo rero uhisemo kandi uyikoresha, imikorere yayo mubushyuhe butandukanye isanzwe itekerezwa.

Igikorwa cyo kwangirika k'ubushyuhe bwa hydroxypropyl methylcellulose (HPMC) gikubiyemo intambwe nyinshi, zikaba ahanini ziterwa n'ubushyuhe, ikirere, uburemere bwa molekile n'ibirimo ubuhehere. Uburyo bwa degradation yubushyuhe burimo umwuma, kubora hydroxyl nu munyururu wuruhande, hamwe no gutandukanya urunigi nyamukuru. Ibiranga ubushyuhe bwumuriro wa HPMC bifite akamaro gakomeye mubijyanye no gutegura imiti, ibikoresho byubwubatsi, nibindi. Kubwibyo rero, gusobanukirwa byimazeyo imyitwarire yangirika yubushyuhe ningirakamaro mugutezimbere igishushanyo mbonera no kunoza imikorere yibicuruzwa. Mubushakashatsi buzaza, ubushyuhe bwumuriro wa HPMC burashobora kunozwa muguhindura, ukongeramo stabilisateur, nibindi, bityo ukagura umurima wabyo.