In isticmaalkaHydroxypropyl methyl cellulose HPMC, waxaan inta badan aragnaa in ay asal ahaan u kala qaybsan tahay laba nooc: degdeg iyo aayar kala diri. Aynu fahano farqiga u dhexeeya kala dirida degdega ah iyo kala dirida gaabis ah ee hydroxypropyl methyl cellulose.
Instant HPMC waxaa loola jeedaa isticmaalka wakiilka cross-linking ee daaweynta dusha ee habka wax soo saarka, si HPMC si deg deg ah loo kala firdhi karaa biyo qabow, laakiin ma xal dhab ah, iyada oo walaaqaya labis, viscosity si tartiib ah u kaca, taas oo ah, kala diri;
HPMC ee qunyar u milma waxa kale oo loogu yeedhi karaa alaabta dhalaalaysa. Marka biyaha qabow la kulmo, si degdeg ah ayaa loogu kala firdhi karaa biyo kulul. Adiga oo si siman u walaaqaya, heerkulka xalku wuxuu hoos ugu dhacayaa heerkul gaar ah. (Heerkulka jelkeenu waa qiyaastii 60°C), viscosity-ku si tartiib ah ayuu u soo muuqan doonaa ilaa jel hufan oo dhegdheg leh laga sameeyo.
Halkan waxaa ah farqiga u dhexeeya xalka degdega ah iyo xalka gaabis ah. Haddii aad wax su'aalo ah ka qabto aqoontan, waxaad sidoo kale nala soo xiriiri kartaa.
Hydroxypropyl methyl celluloseHPMCwaxay dib u dhigtaa fuuq-celinta sibidhka
Ku darista hydroxypropyl methyl cellulose sibidhka waxay hoos u dhigtaa fuuq-celinta. Haddaba maxaad ka taqaanaa sida ay u shaqeyso? Aynu eegno hydroxypropyl methyl cellulose si aan u daahno fuuq-celinta sibidhka. Mabda'a.
1. Ion dhaqdhaqaaqa khalkhalka mala awaalka
Waxaan ku qiyaasnay in hydroxypropyl methyl cellulose ay kordhin doonto viscosity ee xalalka daldaloolada, caqabad ku ah heerka dhaqdhaqaaqa ionic, iyo dib u dhigista fuuq-celinta sibidhka. Si kastaba ha ahaatee, viscosity-ka hoose ethers cellulose ee tijaabadan ayaa lahaa awood xoogan oo dib u dhigista fuuq-celinta sibidhka. Sidaa darteed, malahani waa mid aan sax ahayn. Pourchez iyo al. sidoo kale shaki this mala-awaalka. Dhab ahaantii, wakhtiga socdaalka ion ama socdaalka waa mid aad u gaaban, sida muuqata maaha mid la mid ah dib u dhigista fuuq-celinta sibidhka.
2. Xaalufinta alkaline
Polysaccharides waxay si sahal ah u hoos u dhigtaa xaaladaha alkalineka si ay u soo saaraan hydroxyl karboksilic acids oo dib u dhigaya fuuq-celinta sibidhka. Sidaa darteed, fuuq-celinta dib-u-dhaca ee hydroxypropyl methyl cellulose ayaa laga yaabaa inay sabab u tahay hoos-u-dhac ku yimaada dareeraha sibidhka alkaline si ay u sameeyaan asiidhyada hydroxycarboxylic. Si kastaba ha ahaatee, Pourchez et al. Waxaa la ogaaday in ether-ka cellulose-ku ay aad u deggan yihiin xaaladaha alkaline-ka, hoos u dhac yar oo kaliya, iyo alaabooyinka hoos u dhaca ayaa saameyn yar ku yeeshay dib u dhigista fuuq-celinta sibidhka.
3, adsorption
Adsorption waxay noqon kartaa hydroxypropyl methyl cellulose block fuuq-celinta sibidhka sababta dhabta ah ayaa ah in waxyaabo badan oo lagu daro organic lagu dhajin doono qaybaha sibidhka iyo alaabta fuuqbaxa, ka hortagga kala dirida qaybaha sibidhka iyo crystallization ee alaabta fuuq-baxa, si dib loogu dhigo fuuq-celinta iyo uumiga sibidhka. Pourchez iyo al. Waxaa la ogaaday in ethers-ka cellulose-ku si sahal ah loogu dhajiyay dusha sare ee alaabta fuuq-baxa sida calcium hydroxide, CSH gel iyo calcium aluminate hydrate, laakiin aan si sahal ah loogu dhejin ettringite iyo wejiyada aan biyo lahayn. Waxaa intaa dheer, marka laga hadlayo ether cellulose, awoodda xajinta ee HEC way ka xoog badan tahay bararka MC. Hoosta waxa ku jira hydroxyethyl ee HEC ama hydroxypropyl gudahaHPMC, sida ay u xoog badan tahay awoodda adsorption: sida alaabta fuuq-celinta, awoodda adsorption ee calcium hydroxide ayaa ka xoog badan kan CSH. Falanqaynta dheeraadka ah ayaa sidoo kale muujinaysa in awoodda adsorption ee alaabta fuuq-celinta iyo ether cellulose ay la xiriirto dib-u-dhac ku yimaada fuuq-celinta sibidhka: xoojinta adsorption-ka, dib-u-dhacyada ayaa sii muuqda, laakiin ettringite adsorption of ether cellulose waa daciif, laakiin samaynteeda, laakiin tani waxay si weyn dib u dhigtay. ether cellulose ee tricalcium silicate iyo alaabteeda fuuqbaxa waxay leedahay adsorption xoog leh, waxay si cad u daahinaysaa habka fuuq-celinta ee wajiga silicate, qadarka adsorption ee ettringite waa mid aad u hooseeya, laakiin dib u dhigista ettringite waa mid cad, sababtoo ah dib u dhigista ettringite dib u dhigista waxaa saameeya Ca 2 + dheelitirka xalka, waa kordhinta ether ee cellulose. Fuuq-celinta silicate ee daahday ayaa sii socotay.
Kuwani waa hydroxypropyl methyl cellulose dib u dhigista mabda'a fuuq-celinta sibidhka. Waxaan rajeyneynaa in aqoontani ay awood u siin doonto qof walba inuu fahmo sida alaabtu u shaqeyso oo ay si fiican u isticmaasho.
Waqtiga boostada: Abriil-26-2024