Saamaynta dhumucda ee hydroxypropyl methylcellulose

Hydroxypropyl methylcelluloseHPMCwuxuu siinayaa hoobiye qoyan oo leh viscosity aad u fiican, kaas oo si weyn u kordhin kara isku-xidhka u dhexeeya hoobiye qoyan iyo lakabka salka, iyo hagaajinta waxqabadka ka-hortagga ee hoobiye. hoobiye. Saamaynta dhumucdeeda ee ether cellulose sidoo kale waxay kordhin kartaa isku mid ahaanshaha iyo awoodda ka-hortagga kala-firdhinta walxaha cusub ee sibidhka ku salaysan, ka hortagga delamination, kala-soocidda iyo dhiig-baxa hoobiye iyo shubka, waxaana loo isticmaali karaa shubka-xoojinta fiber-ka, shubka biyaha hoostooda iyo is-xakamaynta. shuban .

Hydroxypropyl methylcellulose waxay kordhisaa viscosity ee walxaha sibidhka ku salaysan ee ka soo baxa xuubka etherka cellulose. Viscosity ee xal ether cellulose waxaa sida caadiga ah lagu qiimeeyaa index "viskosity". Viscosity ee etherka cellulose guud ahaan waxa ay tilmaamaysaa xaddi gaar ah (sida 2%) ee dareeraha etherka cellulose ee heerkul cayiman (sida 20°C) iyo xiirid iyadoo lagu jiro xaalad xawli ah (ama heerka wareega, sida 20 rpm).

Viscosity waa halbeeg muhiim ah oo lagu qiimeeyo waxqabadka etherka cellulose. Marka uu sareeyo viscosity of hydroxypropyl methylcellulose xal, si fiican u viscosity ee walxaha sibidhka ku salaysan, si fiican u adhesion ee substrate, si fiican u anti-sagging iyo ka hortagga kala firdhiso. Xoog badan, laakiin haddii uu viscositykiisu aad u weyn yahay, waxay saamayn doontaa dareeraha iyo shaqaynta alaabta sibidhka ku salaysan (sida mindiyaha dhejiska dhejiska ah marka lagu dhejiyo dhismaha hoobiye). Sidaa darteed, viscosity ether cellulose ee loo isticmaalo hoobiye-qalalan-qallalan inta badan waa 15,000 ~ 60,000 mPa. S-1, hoobiyeyaasha is-heereeya iyo shubka is-xakamaynta ee u baahan dheecaan sare waxay u baahan yihiin viscosity hoose ee eter cellulose.

Intaa waxaa dheer, saameynta dhumucda ee hydroxypropyl methylcellulose waxay kordhisaa baahida biyaha ee walxaha ku salaysan sibidhka, taas oo kordhinaysa dhalidda hoobiye.

Viscosity ee xalka hydroxypropyl methylcellulose waxay kuxirantahay arrimaha soo socda:

Cellulose ether miisaanka molecular (ama heerka polymerization) iyo feejignaanta, heerkulka xalka, heerka dhogorta, iyo hababka tijaabada.

1. Heerka sare ee polymerization of cellulose ether, waa weyn yahay miisaanka kelli, iyo sare viscosity ee ay xal aqueous;

2. Marka loo eego qiyaasta sare ee qiyaasta (ama xoojinta) ether cellulose, waxay sare u kacdaa viscosity ee xalkeeda aqueous, laakiin fiiro gaar ah waa in la bixiyaa xulashada qiyaasta ku habboon marka la isticmaalayo, si looga fogaado qiyaasta xad-dhaafka ah oo saameyn ku yeelata waxqabadka shaqada ee hoobiye. iyo shub;

3. Sida dareerayaasha intooda badan, viscosity of cellulose ether xal waxay hoos u dhigi doontaa korodhka heerkulka, iyo xoojinta sare ee etherka cellulose, saamaynta heerkulka;

4. Xalalka ether cellulose sida caadiga ah waa pseudoplastics leh sifooyinka khafiifinta xiirta. Markasta oo uu sareeyo heerka dhogorta inta lagu jiro baaritaanka, ayaa hoos u dhigaya viscosity-ga.

Sidaa darteed, isku-xidhka hoobiyeyaasha ayaa hoos u dhici doona sababtoo ah ficilka xoogga dibadda, taas oo faa'iido u leh dhismaha xoqidda, si ay hoobiyeyaashu u helaan shaqo fiican iyo isku-xirnaan isku mid ah. Si kastaba ha ahaatee, marka fiirsashada ee xal ether cellulose waa mid aad u hooseeya iyo viscosity waa mid aad u yar, waxay tusi doontaa sifooyinka dheecaanka Newtonian. Marka fiirsigu kordho, xalku si tartiib tartiib ah ayuu u muujin doonaa sifooyinka dareeraha pseudoplastic, iyo heerka sare ee feejignaanta, ayaa si cad u muuqda pseudoplasticity.