Mbiri ndi Chidule
Cellulose ether ndi mankhwala opangidwa ndi polymer cellulose achilengedwe pogwiritsa ntchito mankhwala. Pambuyo popanga cellulose nitrate ndi cellulose acetate m'zaka za m'ma 1800, akatswiri a zamankhwala apanga mitundu yosiyanasiyana ya ma cellulose derivatives a ma cellulose ether ambiri, ndipo minda yatsopano yogwiritsidwa ntchito yapezeka mosalekeza, kuphatikizapo magawo ambiri a mafakitale. Zinthu za cellulose ether monga sodiumcarboxymethyl cellulose (CMC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl hydroxyethyl cellulose (MHEC)ndimethyl hydroxypropyl cellulose (MHPC)ndi ma ether ena a cellulose amadziwika kuti "industrial monosodium glutamate" ndipo akhala akugwiritsidwa ntchito kwambiri pobowola mafuta, kumanga, zokutira, chakudya, mankhwala ndi mankhwala a tsiku ndi tsiku.
Hydroxyethyl methyl cellulose (MHPC) ndi ufa woyera wopanda fungo, wopanda kukoma, wopanda poizoni womwe ungasungunuke m'madzi ozizira kuti upange yankho lowoneka bwino lokhuthala. Lili ndi makhalidwe monga kukhuthala, kumangirira, kufalitsa, kusakaniza, kupanga filimu, kuyimitsa, kuyamwa, kufalitsa, kugwira ntchito pamwamba, kusunga chinyezi ndikuteteza colloid. Chifukwa cha ntchito yogwira ntchito ya yankho lamadzi, lingagwiritsidwe ntchito ngati choteteza colloidal, emulsifier ndi dispersant. Hydroxyethyl methylcellulose aqueous solution ili ndi hydrophilicity yabwino ndipo ndi mankhwala osunga madzi bwino. Chifukwa hydroxyethyl methylcellulose ili ndi magulu a hydroxyethyl, ili ndi mphamvu yabwino yolimbana ndi chimfine, kukhazikika bwino kwa viscosity komanso kukana mildew panthawi yosungidwa kwa nthawi yayitali.
Hydroxyethyl methylcellulose (HEMC) imakonzedwa poika ethylene oxide substituents (MS 0.3 ~ 0.4) mu methylcellulose (MC), ndipo kukana kwake mchere kumakhala bwino kuposa kwa ma polima osasinthidwa. Kutentha kwa gelation kwa methylcellulose nakonso kumakhala kokwera kuposa kwa MC.
Kapangidwe
Mbali
Makhalidwe akuluakulu a hydroxyethyl methylcellulose (HEMC) ndi awa:
1. Kusungunuka: Kusungunuka m'madzi ndi zinthu zina zachilengedwe zosungunulira. HEMC imatha kusungunuka m'madzi ozizira. Kuchuluka kwake kwakukulu kumangotsimikiziridwa ndi kukhuthala. Kusungunuka kumasiyana malinga ndi kukhuthala. Kukhuthala kukakhala kochepa, kusungunuka kumakhala kwakukulu.
2. Kukana Mchere: Zopangidwa ndi HEMC ndi ma ether a cellulose omwe si a ionic ndipo si ma polyelectrolyte, kotero zimakhala zokhazikika m'madzi amchere pamene pali mchere wachitsulo kapena ma electrolyte achilengedwe, koma kuwonjezera ma electrolyte kwambiri kungayambitse kufalikira kwa madzi ndi mvula.
3. Ntchito ya pamwamba: Chifukwa cha ntchito ya pamwamba ya yankho lamadzi, ingagwiritsidwe ntchito ngati choteteza cha colloidal, emulsifier ndi dispersant.
4. Gel wotentha: Pamene yankho lamadzi la zinthu za HEMC litenthedwa kufika kutentha kwinakwake, limakhala losawoneka bwino, losapanga ma gel, ndipo limatuluka, koma likazizira nthawi zonse, limabwerera ku mkhalidwe woyambirira wa yankho, ndipo kutentha komwe gel iyi ndi mvula zimachitika makamaka kumadalira mafuta odzola, zothandizira zopachika, ma colloid oteteza, ma emulsifiers ndi zina zotero.
5. Kusagwira bwino ntchito kwa kagayidwe kachakudya komanso fungo lochepa: HEMC imagwiritsidwa ntchito kwambiri mu chakudya ndi mankhwala chifukwa sidzasinthidwa kukhala kagayidwe kachakudya ndipo ili ndi fungo lochepa komanso fungo lochepa.
6. Kukana chimfine: HEMC ili ndi kukana kwabwino kwa chimfine komanso kukhazikika kwabwino kwa kukhuthala poisunga kwa nthawi yayitali.
7. Kukhazikika kwa PH: Kukhuthala kwa yankho lamadzi la zinthu za HEMC sikukhudzidwa kwambiri ndi asidi kapena alkali, ndipo pH ndi yokhazikika mkati mwa 3.0 mpaka 11.0.
Kugwiritsa ntchito
Hydroxyethyl methylcellulose ingagwiritsidwe ntchito ngati choteteza cha colloidal, emulsifier ndi dispersant chifukwa cha ntchito yake yogwira ntchito pamwamba pa madzi. Zitsanzo za momwe imagwiritsidwira ntchito ndi izi:
1. Zotsatira za hydroxyethyl methylcellulose pa ntchito ya simenti. Hydroxyethyl methylcellulose ndi ufa woyera wopanda fungo, wopanda kukoma, wopanda poizoni womwe ungasungunuke m'madzi ozizira kuti upange yankho lowoneka bwino lokhuthala. Lili ndi makhalidwe monga kukhuthala, kumangirira, kufalitsa, kusakaniza, kupanga filimu, kuyimitsa, kuyamwa, kufalitsa, kugwira ntchito pamwamba, kusunga chinyezi ndi kuteteza colloid. Popeza yankho lamadzi lili ndi ntchito yogwira ntchito pamwamba, lingagwiritsidwe ntchito ngati choteteza colloidal, emulsifier ndi dispersant. Hydroxyethyl methylcellulose yankho lamadzi lili ndi hydrophilicity yabwino ndipo ndi chothandizira kusunga madzi bwino.
2. Utoto wofewa kwambiri umakonzedwa, womwe umapangidwa ndi zinthu zotsatirazi m'magawo polemera: 150-200 g ya madzi oyeretsedwa; 60-70 g ya emulsion yoyera ya acrylic; 550-650 g ya calcium yolemera; 70-90 g ya ufa wa talcum; Yankho lamadzi la base cellulose 30-40g; yankho lamadzi la lignocellulose 10-20g; chothandizira kupanga filimu 4-6g; mankhwala opha tizilombo ndi fungicide 1.5-2.5g; chosungunula 1.8-2.2g; chonyowetsa 1.8-2.2g; 3.5-4.5g; Ethylene glycol 9-11g; Yamadzi a hydroxyethyl methylcellulose amapangidwa posungunula 2-4% ya hydroxyethyl methylcellulose m'madzi; Yamadzi a lignocellulose amapangidwa ndi 1-3% ya Lignocellulose amapangidwa posungunula m'madzi.
Kukonzekera
Njira yokonzekera hydroxyethyl methyl cellulose, njira yake ndi yakuti thonje loyengedwa limagwiritsidwa ntchito ngati zinthu zopangira, ndipo ethylene oxide imagwiritsidwa ntchito ngati chothandizira kupangira hydroxyethyl methyl cellulose. Zigawo zolemera za zipangizo zopangira hydroxyethyl methylcellulose ndi izi: magawo 700-800 a toluene ndi isopropanol osakaniza ngati solvent, magawo 30-40 a madzi, magawo 70-80 a sodium hydroxide, magawo 80-85 a thonje loyengedwa, mphete magawo 20-28 a oxy ethane, magawo 80-90 a methyl chloride, magawo 16-19 a glacial acetic acid; njira zenizeni ndi izi:
Gawo loyamba, mu ketulo yoyankhira, onjezerani toluene ndi isopropanol osakaniza, madzi, ndi sodium hydroxide, tenthetsani mpaka 60-80 ° C, sungani kutentha kwa mphindi 20-40;
Gawo lachiwiri, alkalizing: kuziziritsa zinthu zomwe zili pamwambapa mpaka 30-50°C, onjezerani thonje loyengedwa bwino, thirani toluene ndi isopropanol mixture solvent, vacuum cleaner mpaka 0.006Mpa, mudzaze nayitrogeni m'malo atatu, ndipo mutatha kusintha Alkalinization, mikhalidwe ya alkalizing ndi iyi: nthawi ya alkalizing ndi maola awiri, ndipo kutentha kwa alkalizing ndi 30°C mpaka 50°C;
Gawo lachitatu, etherification: pambuyo poti alkaliization yatha, reactor imachotsedwa ku 0.05-0.07MPa, ndipo ethylene oxide ndi methyl chloride zimawonjezedwa kwa mphindi 30-50; gawo loyamba la etherification: 40-60°C, maola 1.0-2.0, kuthamanga kumayendetsedwa pakati pa 0.15 ndi 0.3Mpa; gawo lachiwiri la etherification: 60 ~ 90℃, maola 2.0 ~ 2.5, kuthamanga kumayendetsedwa pakati pa 0.4 ndi 0.8Mpa;
Gawo lachinayi, kuletsa kusungunuka: onjezani glacial acetic acid yoyezedwa pasadakhale ku ketulo ya mvula, kanikizani mu zinthu zomwe zatenthedwa kuti zithetse kusungunuka, kwezani kutentha kufika pa 75-80°C kuti mvula igwe, kutentha kumakwera kufika pa 102°C, ndipo pH imapezeka kuti ndi 6. Nthawi ya 8 koloko, kusungunuka kumatsirizika; thanki yochotsera kusungunuka imadzazidwa ndi madzi apampopi okonzedwa ndi chipangizo chosinthira cha osmosis pa 90°C mpaka 100°C;
Gawo lachisanu, kutsuka pogwiritsa ntchito centrifugal: chinthu chomwe chili mu gawo lachinayi chimayendetsedwa ndi centrifuge kudzera mu screw centrifuge yopingasa, ndipo chinthucho chimasamutsidwa ku thanki yotsukira yodzazidwa ndi madzi otentha pasadakhale kuti chitsukidwe;
Gawo lachisanu ndi chimodzi, kuumitsa pogwiritsa ntchito centrifuge: zinthu zotsukidwa zimalowetsedwa mu choumitsira pogwiritsa ntchito screw centrifuge yopingasa, ndipo zinthuzo zimaumitsidwa pa 150-170°C, ndipo zinthu zoumazo zimaphwanyidwa ndikupakidwa.
Poyerekeza ndi ukadaulo womwe ulipo wopangira ether ya cellulose, njira yatsopanoyi imagwiritsa ntchito ethylene oxide ngati chothandizira kupangira hydroxyethyl methyl cellulose, yomwe ili ndi kukana bwino kwa mildew chifukwa chokhala ndi magulu a hydroxyethyl. Ili ndi kukhazikika kwabwino kwa viscosity komanso kukana mildew ikasungidwa kwa nthawi yayitali. Itha kugwiritsidwa ntchito m'malo mwa ma ether ena a cellulose.
Nthawi yotumizira: Epulo-25-2024