HPMC rau zaj duab xis txheej

HPMC rauZaj duab xis txheej yog txheej txheem ntawm kev tsim ib zaj duab xis nyias ntawm ib lub polymer tshaj ib qho khoom npaj. Piv txwv li, ib txheej ntawm cov khoom siv polymer ruaj khov yog txau ib yam nkaus rau ntawm daim ntawv dawb los ntawm kev txau los ntawm cov txheej txheem yas txheej ob peb microns tuab, thiaj li ua tiav cov nyhuv xav tau. Qhov tsim ntawm txheej txheej ntawm zaj duab xis sab nraum lub ntsiav tshuaj yog tias ib lub ntsiav tshuaj ua raws li cov khoom siv polymer txheej tom qab dhau los ntawm thaj chaw tshuaj tsuag, thiab tom qab ntawd tau txais ib feem ntawm cov khoom txheej tom qab ziab. Tom qab rov ua dua adhesion thiab ziab, txheej txheej tiav kom txog thaum tag nrho saum npoo ntawm qhov kev npaj tau npog tag nrho. Zaj duab xis txheej yog ib zaj duab xis tas mus li, thickness feem ntau ntawm 8 mus rau 100 microns, ib qho degree ntawm elasticity thiab saj zawg zog, nruj nreem rau ntawm qhov chaw ntawm cov tub ntxhais.

Nyob rau hauv 1954, Abbott tau tsim thawj pawg ntawm cov ntaub ntawv ua lag luam, txij thaum ntawd los, nrog kev txhim kho txuas ntxiv thiab kev ua tiav ntawm cov cuab yeej tsim khoom thiab thev naus laus zis, cov ntaub ntawv zaj duab xis polymer tau raug tso tawm, yog li cov txheej txheem txheej txheej txheej txheem tau tsim sai. Tsis tsuas yog ntau yam, ntau thiab zoo ntawm cov xim txheej txheej tau nce sai, tab sis kuj yog hom, cov ntaub ntawv thiab cov yam ntxwv ntawm txheej txheej tshuab, txheej txheej khoom thiab txheej zaj duab xis nrog rau cov txheej txheem ntawm TCM cov tshuaj tau tsim zoo heev. Yog li ntawd, daim ntawv thov ntawm zaj duab xis txheej tshuab tau dhau los ua qhov xav tau thiab kev loj hlob ntawm cov chaw lag luam tshuaj los txhim kho cov khoom zoo.

Thaum ntxov siv cov txheej txheem zaj duab xis ua cov ntaub ntawv, tseem muaj ntau cov khoom siv HPMCHydroxypropyl methylcellulose yog ib qho khoom siv zooraws li cov ntaub ntawv Membrane. Nws yog purificationHPMCcellulose los ntawm paj rwb lint lossis ntoo pulp, thiab sodium hydroxide tov kom muaj kev cuam tshuam qhov o ntawm alkali cellulose, thiab tom qab ntawd nrog chloromethane thiab propylene oxide kho kom tau methyl hydroxypropyl cellulose etherHPMC, cov khoom kom tshem tawm impurities tom qab ziab, crushing, ntim. Feem ntau, tsawg viscosity HPMC yog siv los uazaj duab xistxheej txheej, thiab 2% ~ 10% tov yog siv los ua txheej txheej. Qhov tsis zoo yog qhov viscosity loj dhau thiab qhov nthuav dav yog qhov muaj zog heev.

Lub cim thib ob ntawm cov khoom siv ua yeeb yaj kiab yog polyvinyl cawv (PVA). Polyvinyl cawv yog tsim los ntawm alcoholysis ntawm polyvinyl acetate. Vinyl cawv rov ua haujlwm tsis tuaj yeem siv los ua cov tshuaj reactants vim tias lawv tsis ua raws li qhov ntau thiab purity xav tau rau polymerization. Nyob rau hauv methanol, ethanol los yog ethanol thiab methyl acetate tov tov nrog alkali hlau los yog inorganic acid raws li catalyst, hydrolysis yog ceev.

PVA yog dav siv nyob rau hauv zaj duab xis txheej. Vim nws yog insoluble nyob rau hauv dej ntawm chav tsev kub, nws yog feem ntau coated nrog txog 20% ​​dej dispersion. Cov dej vapor thiab oxygen permeability ntawm PVA yog qis dua HPMC thiab EC, yog li lub peev xwm thaiv cov dej vapor thiab oxygen muaj zog dua, uas tuaj yeem tiv thaiv cov chips zoo dua.

Plasticizer yog hais txog cov khoom siv uas tuaj yeem ua kom cov yas ntawm cov ntaub ntawv tsim cov yeeb yaj kiab. Qee cov ntaub ntawv tsim cov yeeb yaj kiab hloov pauv lawv lub cev tom qab qhov kub thiab txias, thiab kev txav mus los ntawm lawv cov macromolecules ua me me, ua rau cov txheej txheej nyuaj thiab nkig, tsis muaj qhov tsim nyog yooj, thiab yog li yooj yim tawg. Plasticizer tau ntxiv los txo cov iav hloov pauv kub (Tg) thiab ua kom cov txheej txheem yooj yim. Feem ntau siv plasticizers yog amorphous polymers nrog qhov hnyav molecular thiab muaj kev sib raug zoo nrog cov ntaub ntawv ua yeeb yaj kiab. Cov plasticizer insoluble pab txo cov permeability ntawm txheej, yog li ua kom muaj kev ruaj ntseg ntawm kev npaj.

Nws yog feem ntau ntseeg hais tias cov txheej txheem ntawm plasticizer yog cov plasticizer molecules yog embedded nyob rau hauv lub polymer saw, uas thaiv kev sib cuam tshuam ntawm polymer molecules mus rau ib tug loj npaum li cas. Kev sib cuam tshuam yog yooj yim dua thaum kev sib cuam tshuam ntawm polymer-plasticizer muaj zog dua li kev sib cuam tshuam ntawm polymer-plasticizer. Yog li, cov cib fim rau cov ntu polymer txav tau nce.

Lub cim thib peb ntawm cov ntaub ntawv tsim cov yeeb yaj kiab yog cov plasticizer los ntawm cov txheej txheem tshuaj grafted hauv zaj duab xis tsim cov khoom siv polymer

Piv txwv li, LUB tshiab tsim cov khoom siv Kollicoat® IR qhia los ntawm BASF yog tias PEG yog tshuaj grafted rau cov saw ntev ntawm PVA polymer yam tsis ntxiv cov yas, yog li nws tuaj yeem zam kev tsiv teb tsaws ntawm pas dej tom qab txheej.