01. Kuunzwa kwe cellulose
Cellulose ipolysaccharide yakakura inoumbwa neglucose. Hainyungudike mumvura uye mune zvinonyungudutsa zvipenyu. Ndiyo chinhu chikuru chemadziro emasero emiti, uye ndiyo polysaccharide yakapararira zvakanyanya uye yakawanda kwazvo.
Cellulose ndiyo inowanikwa zvakanyanya pasi rose, uye ndiyo polymer yechisikigo ine huwandu hwakakura kwazvo. Ine zvakanakira zvekuva inogona kushandiswazve, inogona kuora zvachose, uye inoenderana zvakanaka nezvinhu zvipenyu.
02. Zvikonzero zvekugadzirisa cellulose
Makoromorekuru eCellulose ane huwandu hwakawanda hwemapoka e -OH. Nekuda kwemhedzisiro yezvisungo zvehydrogen, simba riri pakati pemakoromorekuru rakakura, izvo zvinotungamira kune enthalpy yakakura yekunyunguduka △H; kune rumwe rutivi, kune mhete mumakoromorekuru ecellulose. Kufanana nechimiro, kuomarara kwecheni yemamorekuru kwakakura, izvo zvinotungamira kune shanduko diki yekunyunguduka kwe entropy ΔS. Zvikonzero izvi zviviri zvinoita kuti tembiricha ye cellulose yakanyunguduka (= △H / △S ) iwedzere, uye tembiricha yekuora kwe cellulose yakaderera. Naizvozvo, kana cellulose yadziiswa kune imwe tembiricha, fibers dzichaonekwa. Chiitiko chekuti cellulose yakaora isati yatanga kunyunguduka, saka, kugadziriswa kwezvinhu zve cellulose hakugone kushandisa nzira yekutanga kunyunguduka uye kuumbwa.
03. Kukosha kwekuchinja kwe cellulose
Nekuderera zvishoma nezvishoma kwezviwanikwa zvemafossil uye matambudziko makuru ezvakatipoteredza anokonzerwa nemachira emafiber emakemikari, kugadzirwa nekushandiswa kwezvinhu zvemafiber zvinogadziriswazve zvakasikwa kwave chimwe chezvinhu zvinonyanya kufarirwa nevanhu. Cellulose ndiyo inowanikwa zvakanyanya muzvinhu zvakasikwa. Ine hunhu hwakanaka hwakadai se hygroscopicity, antistatic, mhepo yakasimba inoyerera, dhayi yakanaka, kupfeka zvakanaka, nyore kugadzira machira, uye kuora kwehupenyu. Ine hunhu husingaenzaniswi nemafiber emakemikari.
Mamorekuru eCellulose ane huwandu hwakawanda hwema hydroxyl groups, ayo ari nyore kugadzira intramolecular ne intermolecular hydrogen bonds, uye anoora pakupisa kwakanyanya pasina kunyunguduka. Zvisinei, cellulose ine reactivity yakanaka, uye hydrogen bond yayo inogona kuparadzwa nekuchinja kwemakemikari kana grafting reaction, izvo zvinogona kuderedza zvinobudirira melting point. Sezvigadzirwa zvakasiyana-siyana zvemaindasitiri, inoshandiswa zvakanyanya mumachira, membrane separation, mapurasitiki, fodya uye coatings.
04. Kugadziriswa kweCellulose etherification
Cellulose ether imhando ye cellulose derivative inowanikwa nekuchinja etherification ye cellulose. Inoshandiswa zvakanyanya nekuda kwekukora kwayo kwakanaka, emulsification, suspension, firimu formation, protective colloid, hunyoro hwekuchengetedza, uye hunhu hwekunamatira. Inoshandiswa mukudya, mishonga, kugadzira mapepa, pendi, zvinhu zvekuvaka, nezvimwewo.
Kugadziriswa kwe cellulose musanganiswa wezvinhu zvinogadzirwa nekuita kwemapoka ehydroxyl pa cellulose molecular chain ne alkylating agents pasi pemamiriro e alkaline. Kushandiswa kwemapoka ehydroxyl kunoderedza huwandu hwe intermolecular hydrogen bonds kuderedza masimba e intermolecular, nokudaro Kuvandudza kugadzikana kwekupisa kwe cellulose, kuvandudza mashandiro ekugadzirisa zvinhu, uye panguva imwe chete kuderedza poindi yekunyunguduka kwe cellulose.
Mienzaniso yemigumisiro yekuchinja kwe etherification pane mamwe mabasa e cellulose:
Vachishandisa donje rakanatswa sezvinhu zvakakosha, vaongorori vakashandisa nzira yekuwedzera ether kugadzirira carboxymethyl hydroxypropyl cellulose complex ether ine maitiro akafanana, viscosity yakakwira, acid resistance yakanaka uye salt resistance kuburikidza ne alkalization uye etherification reactions. Vachishandisa nzira yekuwedzera ether nhanho imwe chete, carboxymethyl hydroxypropyl cellulose yakagadzirwa ine salt resistance yakanaka, acid resistance uye solubility yakanaka. Nekuchinja huwandu hwepropylene oxide ne chloroacetic acid, zvigadzirwa zvine carboxymethyl ne hydroxypropyl zvirimo zvakasiyana zvinogona kugadzirwa. Mhedzisiro yebvunzo inoratidza kuti carboxymethyl hydroxypropyl cellulose inogadzirwa nenzira ye one-step ine short-production cycle, low solvent consumption, uye chigadzirwa chine anti-acuity yakanaka kune monovalent ne divalent salts uye acid resistance yakanaka.
05. Tarisiro yekuchinja kwe etherification ye cellulose
Cellulose chinhu chakakosha chemakemikari nemakemikari chine zviwanikwa zvakawanda, chine hushamwari kune zvakatipoteredza, uye chinodzokororwa. Zvinobva mukuchinja kwe cellulose etherification zvine mashandiro akanaka, mashandisirwo akasiyana-siyana uye mhedzisiro yakanaka pakushandisa, uye zvinosangana nezvinodiwa nehupfumi hwenyika zvakanyanya. Uye zvinodiwa pakukura kwevanhu, nekufambira mberi kwetekinoroji uye kuzadzikiswa kwekutengeserana mune ramangwana, kana zvinhu zvakagadzirwa uye nzira dzekugadzira dze cellulose derivatives dzikagona kushandiswa zvakanyanya, zvichashandiswa zvizere uye zvichashanda munzvimbo dzakasiyana siyana. Kukosha
Nguva yekutumira: Kukadzi-20-2023