Mbiri ndi Chidule
Cellulose ether ndi chinthu chomwe chimagwiritsidwa ntchito kwambiri polima polima chopangidwa kuchokera ku cellulose yachilengedwe ya polima kudzera mumankhwala. Pambuyo popanga ma cellulose nitrate ndi cellulose acetate m'zaka za zana la 19, akatswiri a zamankhwala apanga zotuluka zingapo za cellulose za ma cellulose ethers ambiri, ndipo magawo atsopano ogwiritsira ntchito apezeka mosalekeza, kuphatikiza magawo ambiri ogulitsa. Ma 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 cellulose ethers amadziwika kuti "industrial monosodium glutamate" ndipo amagwiritsidwa ntchito kwambiri pobowola mafuta, zomangamanga, zokutira, chakudya, mankhwala ndi mankhwala a tsiku ndi tsiku.
Hydroxyethyl methyl cellulose (MHPC) ndi ufa woyera wopanda fungo, wosakoma, wopanda poizoni womwe ukhoza kusungunuka m'madzi ozizira kuti ukhale wowonekera bwino wa viscous. Lili ndi makhalidwe a thickening, kumanga, kubalalika, emulsifying, filimu kupanga, suspending, adsorbing, gelling, pamwamba yogwira, kusunga chinyezi ndi kuteteza colloid. Chifukwa cha malo yogwira ntchito ya njira amadzimadzi, angagwiritsidwe ntchito ngati colloidal zoteteza wothandizila, emulsifier ndi dispersant. Hydroxyethyl methylcellulose yankho lamadzimadzi lili ndi hydrophilicity yabwino ndipo ndi yothandiza posungira madzi. Chifukwa hydroxyethyl methylcellulose ili ndi magulu a hydroxyethyl, imakhala ndi mphamvu zotsutsana ndi mildew, kukhazikika kwa viscosity komanso kukana kwa mildew panthawi yosungirako nthawi yaitali.
Hydroxyethyl methylcellulose (HEMC) imakonzedwa poyambitsa ethylene oxide substituents (MS 0.3 ~ 0.4) mu methylcellulose (MC), ndipo kukana kwake mchere kumakhala bwino kuposa ma polima osasinthika. Kutentha kwa gelation kwa methylcellulose ndikokweranso kuposa kwa MC.
Kapangidwe
Mbali
Makhalidwe akuluakulu a hydroxyethyl methylcellulose (HEMC) ndi awa:
1. Kusungunuka: Kusungunuka m'madzi ndi zosungunulira za organic. HEMC ikhoza kusungunuka m'madzi ozizira. Kuchuluka kwake kwapamwamba kumangotsimikiziridwa ndi mamasukidwe akayendedwe. Kusungunuka kumasiyanasiyana ndi kukhuthala. Kutsika mamasukidwe akayendedwe, m'pamenenso solubility kwambiri.
2. Kukana kwa mchere: Mankhwala a HEMC ndi osakhala a ionic cellulose ethers ndipo si polyelectrolytes, choncho amakhala okhazikika muzitsulo zamadzimadzi pamene mchere wachitsulo kapena organic electrolytes ulipo, koma kuwonjezera kwambiri kwa electrolytes kungayambitse gelation ndi mpweya.
3. Ntchito yapamwamba: Chifukwa cha ntchito yogwira ntchito yamadzimadzi, imatha kugwiritsidwa ntchito ngati colloidal protective agent, emulsifier ndi dispersant.
4. Gel gel yotentha: Pamene njira yamadzimadzi ya mankhwala a HEMC imatenthedwa ndi kutentha kwina, imakhala opaque, gels, ndi precipitates, koma ikakhazikika mosalekeza, imabwerera ku chikhalidwe choyambirira cha yankho, ndipo kutentha kumene gel osakaniza ndi mpweya zimachitika makamaka Kutengera iwo mafuta odzola, suspending, etc.
5. Metabolic inertness ndi fungo lochepa ndi fungo lonunkhira: HEMC imagwiritsidwa ntchito kwambiri muzakudya ndi zamankhwala chifukwa sichidzapangidwa ndi metabolic ndipo imakhala ndi fungo lochepa komanso fungo labwino.
6. Kulimbana ndi mildew: HEMC ili ndi kukana kwabwino kwa mildew komanso kukhazikika kwa viscosity panthawi yosungidwa kwa nthawi yaitali.
7. Kukhazikika kwa PH: Kuthamanga kwa njira yamadzimadzi ya mankhwala a HEMC sikukhudzidwa kwambiri ndi asidi kapena alkali, ndipo pH yamtengo wapatali imakhala yokhazikika mkati mwa 3.0 mpaka 11.0.
Kugwiritsa ntchito
Hydroxyethyl methylcellulose angagwiritsidwe ntchito ngati colloidal zoteteza wothandizila, emulsifier ndi dispersant chifukwa pamwamba yogwira ntchito mu njira amadzimadzi. Zitsanzo zakugwiritsa ntchito kwake ndi izi:
1. Zotsatira za hydroxyethyl methylcellulose pa ntchito ya simenti. Hydroxyethyl methylcellulose ndi ufa woyera wopanda fungo, wosakoma, wopanda poizoni womwe ukhoza kusungunuka m'madzi ozizira kuti ukhale wowonekera bwino wa viscous. Lili ndi makhalidwe a thickening, kumanga, kubalalika, emulsifying, filimu kupanga, suspending, adsorbing, gelling, pamwamba yogwira, kusunga chinyezi ndi kuteteza colloid. Popeza njira yamadzimadzi imakhala ndi ntchito yogwira ntchito, imatha kugwiritsidwa ntchito ngati colloidal protective agent, emulsifier ndi dispersant. Hydroxyethyl methylcellulose yankho lamadzimadzi lili ndi hydrophilicity yabwino ndipo ndi yothandiza posungira madzi.
2. Utoto wotsitsimula kwambiri umakonzedwa, womwe umapangidwa ndi zinthu zotsatirazi m'magulu ndi kulemera kwake: 150-200 g wa madzi osungunuka; 60-70 g wa emulsion woyera akiliriki; 550-650 g wa kashiamu wolemera; 70-90 g ufa wa talcum; Base cellulose amadzimadzi njira 30-40g; lignocellulose amadzimadzi njira 10-20g; filimu-kupanga thandizo 4-6g; antiseptic ndi fungicide 1.5-2.5g; 1.8-2.2 g; chonyowetsa wothandizira 1.8-2.2g; 3.5-4.5g; ethylene glycol 9-11g; Njira yamadzimadzi ya hydroxyethyl methylcellulose imapangidwa ndi kusungunula 2-4% hydroxyethyl methylcellulose m'madzi; Njira yamadzimadzi ya lignocellulose imapangidwa ndi 1-3% Lignocellulose imapangidwa ndikusungunuka m'madzi.
Kukonzekera
Njira yokonzekera ya hydroxyethyl methyl cellulose, njirayo ndikuti thonje loyengedwa limagwiritsidwa ntchito ngati zopangira, ndipo ethylene oxide imagwiritsidwa ntchito ngati etherification agent pokonzekera hydroxyethyl methyl cellulose. Kulemera kwa zipangizo pokonzekera hydroxyethyl methylcellulose ndi motere: 700-800 mbali toluene ndi isopropanol osakaniza monga zosungunulira, 30-40 mbali ya madzi, 70-80 mbali ya sodium hydroxide, 80-85 mbali woyengedwa thonje, mphete 20-28 mbali ya oxy methylchloride 90, 16-19 magawo a glacial acetic acid; masitepe enieni ndi awa:
Gawo loyamba, mu anachita ketulo, kuwonjezera toluene ndi isopropanol osakaniza, madzi, ndi sodium hydroxide, kutentha kwa 60-80 ° C, kutentha kwa mphindi 20-40;
Gawo lachiwiri, alkalization: kuziziritsa zida pamwambapa 30-50 ° C, onjezani thonje woyengedwa, utsi toluene ndi isopropanol osakaniza zosungunulira, vacuumize kwa 0.006Mpa, lembani nayitrogeni m'malo 3, ndi kuchita pambuyo m'malo Alkalinization, zinthu alkalization ndi: alkalization nthawi ndi 2 hours ndi 50 ° C ° ndi alkalization 50 ° C;
Gawo lachitatu, etherification: pambuyo pa alkalization, riyakitala imasamutsidwa kupita ku 0.05-0.07MPa, ndipo ethylene oxide ndi methyl chloride imawonjezeredwa kwa mphindi 30-50; gawo loyamba la etherification: 40-60 ° C, 1.0-2.0 Maola, kupanikizika kumayendetsedwa pakati pa 0,15 ndi 0.3Mpa; Gawo lachiwiri la etherification: 60～90℃, 2.0～2.5 maola, kupanikizika kumayendetsedwa pakati pa 0,4 ndi 0.8Mpa;
Gawo lachinayi, neutralization: yonjezerani glacial acetic acid pasadakhale ku ketulo yamvula, kanikizani muzinthu zowonongeka kuti musatengeke, kwezani kutentha kwa 75-80 ° C kwa mpweya, kutentha kumakwera mpaka 102 ° C, ndipo pH mtengo umadziwika kuti ndi 6 Pa 8 koloko, desolventization yatha; thanki ya desolventization imadzazidwa ndi madzi apampopi opangidwa ndi chipangizo chosinthira osmosis pa 90 ° C mpaka 100 ° C;
Gawo lachisanu, kutsuka kwa centrifugal: zinthu zomwe zili mu sitepe yachinayi ndi centrifuged kupyolera mu centrifuge yopingasa wononga, ndipo zinthu zolekanitsidwa zimasamutsidwa ku thanki yotsuka yodzaza ndi madzi otentha pasadakhale kutsuka kwa zinthuzo;
Gawo lachisanu ndi chimodzi, kuyanika kwa centrifugal: zinthu zotsukidwa zimatumizidwa mu chowumitsira kudzera pa centrifuge yopingasa, ndipo zinthuzo zimauma pa 150-170 ° C, ndipo zouma zimaphwanyidwa ndikuphatikizidwa.
Poyerekeza ndi ukadaulo wopangira ma cellulose ether, zomwe zidapangidwa pano zimagwiritsa ntchito ethylene oxide ngati etherification agent pokonzekera hydroxyethyl methyl cellulose, yomwe ili ndi kukana bwino kwa mildew chifukwa chokhala ndi magulu a hydroxyethyl. Ili ndi kukhazikika kwa viscosity yabwino komanso kukana kwa mildew panthawi yosungidwa kwanthawi yayitali. Itha kugwiritsidwa ntchito m'malo mwa ma cellulose ethers.
Nthawi yotumiza: Apr-25-2024