Hydroxyethyl methyl Ma cellulose

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 sodium carboxymethyl cellulose (CMC), ethyl cellulose (EC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), methyl hydroxyethyl cellulose (MHEC) ndi methyl hydroxypropyl cellulose (MHPC) ndi ma cellulose ethers ena amadziwika kuti "Industrial monosodium glutamate" ndipo akhala akugwiritsidwa ntchito kwambiri pobowola mafuta, zomangamanga, zokutira, chakudya, mankhwala ndi mankhwala a tsiku ndi tsiku.

Hydroxyethyl methylcellulose(MHEC) ndi ufa woyera wopanda fungo, wosakoma, wopanda poizoni womwe ukhoza kusungunuka m'madzi ozizira kuti apange njira yowonekera yowonekera. Lili ndi makhalidwe a thickening, kumanga, kubalalika, emulsifying, filimu kupanga, suspending, adsorbing, gelling, pamwamba yogwira, kusunga chinyezi ndi kuteteza colloid. Chifukwa cha pamwamba 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 zina. HEMC ikhoza kusungunuka m'madzi ozizira. Kuchuluka kwake kwapamwamba kumangotsimikiziridwa ndi mamasukidwe akayendedwe. Kusungunuka kumasiyanasiyana ndi kukhuthala. M'munsi mamasukidwe akayendedwe, kwambiri solubility.
2. Kukaniza mchere: Zogulitsa za HEMC ndizopanda ma ionic cellulose ethers ndipo si polyelectrolytes, kotero zimakhala zokhazikika muzitsulo zamadzimadzi pamene mchere wachitsulo kapena organic electrolytes ulipo, koma kuwonjezera kwambiri kwa electrolyte kungayambitse kutsekemera ndi mpweya.
3. Zochita Pamwamba: Chifukwa cha ntchito yogwira ntchito yamadzimadzi, imatha kugwiritsidwa ntchito ngati colloidal protective agent, emulsifier ndi dispersant.
4. Gel yotentha: Pamene njira yamadzimadzi ya mankhwala a HEMC imatenthedwa ndi kutentha kwina, imakhala opaque, gels, ndi precipitates, koma ikakhazikika mosalekeza, imabwerera ku njira yoyamba yothetsera, ndi kutentha komwe gel ndi mvula. zimachitika makamaka Kutengera iwo lubricants, suspending zothandizira, zoteteza colloids, emulsifiers etc.
5. Metabolism inert ndi fungo lochepa ndi fungo lonunkhira: HEMC imagwiritsidwa ntchito kwambiri muzakudya ndi zamankhwala chifukwa sichidzasinthidwa ndipo imakhala ndi fungo lochepa komanso fungo labwino.
6. Kulimbana ndi mildew: HEMC ili ndi kukana kwabwino kwa mildew komanso kukhazikika kwa mamachulukidwe abwino pakusungidwa kwanthawi yayitali.
7. Kukhazikika kwa PH: Kuthamanga kwa njira yamadzimadzi ya mankhwala a HEMC sikukhudzidwa kwambiri ndi asidi kapena alkali, ndipo pH mtengo ndi wokhazikika mkati mwa 3.0 mpaka 11.0.

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 pakuchita simenti. Hydroxyethyl methylcellulose ndi ufa woyera wopanda fungo, wosakoma, wopanda poizoni womwe ukhoza kusungunuka m'madzi ozizira kuti upange njira yowonekera yowonekera. 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 wa mpumulo wokhala ndi kusinthasintha kwakukulu umakonzedwa, womwe umapangidwa ndi zinthu zotsatirazi m'magulu ndi kulemera kwake: 150-200 g wa madzi opangidwa ndi deionized; 60-70 g wa emulsion woyera akiliriki; 550-650 g wa kashiamu wolemera; 70-90 g ufa wa talcum; 30-40g base cellulose amadzimadzi njira; 10-20g lignocellulose amadzimadzi njira; 4-6 g wothandizira kupanga mafilimu; 1.5-2.5g antiseptic ndi bactericide; 1.8-2.2g dispersant; 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 methylcellulose, njirayo ndikugwiritsa ntchito thonje woyengedwa ngati zopangira ndi ethylene oxide monga etherification wothandizira kukonzekera hydroxyethyl methylcellulose. Kulemera kwa zipangizo zopangira hydroxyethyl methyl cellulose ndi motere: 700-800 zigawo za toluene ndi isopropanol osakaniza monga zosungunulira, 30-40 mbali ya madzi, 70-80 mbali ya sodium hydroxide, 80-85 mbali ya thonje woyengeka, mphete 20-28 mbali oxyethane, 80-90 mbali methyl kolorayidi, 16-19 mbali glacial asidi asidi; 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 zomwe zili pamwambapa mpaka 30-50 ° C, onjezani thonje woyengedwa, kupoperani toluene ndi isopropanol zosungunulira zosungunulira, kupopera mpaka 0.006Mpa, lembani nayitrogeni m'malo atatu, ndikuchita pambuyo pa Alkalinization. alkalization mikhalidwe ndi: nthawi alkalization ndi 2 hours, ndi alkalization kutentha ndi 30°C mpaka 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: Onjezani glacial acetic acid pasadakhale ku ketulo yamvula, kanikizani muzinthu zomwe zili ndi etherified kuti muchepetse, kwezani kutentha mpaka 75-80 ° C kuti kukhale mvula, kutentha kumakwera mpaka 102 ° C, ndi pH. mtengo 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 monga etherification agent pokonzekera hydroxyethyl methyl cellulose, yomwe ili ndi mphamvu yabwino yotsutsa nkhungu 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.