I-Hydroxyethyl methyl cellulose (HEMC) yi-ether ye-cellulose engeyo-ionic esetyenziswa ngokubanzi kulwakhiwo, iingubo, iiseramikhi, amayeza, ukutya kunye namanye amashishini. I-HEMC ine-solubility efanelekileyo yamanzi, ukuqina, ukugcinwa kwamanzi, ukubunjwa kwefilimu kunye neepropati zokudibanisa, kwaye idlala indima ebalulekileyo kumdaka odibeneyo owomileyo, ipeyinti ye-latex, i-detergent kunye nezinye iindawo.
1. Inkqubo yokuvelisa
1.1 Ukulungiselela imathiriyeli ekrwada
I-HEMC ilungiswa ikakhulu kwi-cellulose yezityalo zendalo, i-methyl chloride (CH₃Cl), i-ethylene oxide (C₂H₄O), i-sodium hydroxide (NaOH) kunye nezinye izinto eziluhlaza.
I-Cellulose: I-pulp yokhuni okanye i-cotton pulp isoloko isetyenziswa njengeyona nto iphambili, efuna ukucoceka okuphezulu kunye nokungcola okumbalwa ukuqinisekisa umgangatho wemveliso.
I-Alkalizer (NaOH): isetyenziselwa ukwenza i-cellulose isebenze kunye nokuphucula umsebenzi wokuphendula.
Umenzeli we-Etherifying (CH₃Cl kunye noC₂H₄O): ukubonelela nge-methyl kunye namaqela e-hydroxyethyl ngokulandelanayo, ukwenzela ukuba i-cellulose ithathe indawo yokuphendula, iphucula ukunyibilika kwamanzi kunye neepropati zokusebenza.
I-solvent ye-Organic (njenge-isopropanol): isetyenziselwa ukunyibilikisa i-reactants, ukulawula indawo yokusabela kunye nokunciphisa ukuphendula kwecala.
1.2 Unyango lwe-alkalization
Emva kokuba i-cellulose ichithwe, isixa esifanelekileyo sesisombululo se-sodium hydroxide yongezwa kwaye unyango lwe-alkalization lwenziwa kwiqondo lokushisa elithile kunye noxinzelelo, oludla ngokuthatha imizuzu engama-30-60. Injongo ephambili ye-alkalization kukwandisa i-cellulose ye-molecular chain kunye nokuphucula i-reactivity yayo kunye ne-etherifying agent. Le nkqubo idla ngokuqhutyelwa kwi-reactor evaliweyo ngokuvuselela ukuqinisekisa ukuba isisombululo se-alkali singena ngokulinganayo kwi-cellulose.
1.3 Ukusabela kwe-Etherification
I-alkalized cellulose iphendula kunye ne-methylation kunye ne-hydroxyethylation reagents (CH₃Cl kunye noC₂H₄O) kwi-reactor ukuvelisa i-hydroxyethyl methyl cellulose. Iimeko zokusabela ziquka:
Ubushushu: 60-90°C
Uxinzelelo: 0.5-1.5 MPa
Ixesha: 2-5 iiyure
Ngexesha lokuphendula, i-methylation kunye ne-hydroxyethylation reactions iqhubeka ngaxeshanye, ukwenzela ukuba i-hydroxyl (-OH) inxalenye ye-cellulose ithathelwe indawo yi-methyl (-OCH).₃) kunye ne-hydroxyethyl (-OCH₂CH₂OH), ngaloo ndlela itshintsha ukunyibilika kwayo kunye neempawu zokujiya. Ukuze kuphuculwe i-degree of substitution (i-DS kunye ne-MS values), ngokuqhelekileyo kuyimfuneko ukunyusa i-odolo kunye nomlinganiselo we-etherification agent agent.
1.4 Ukungathathi hlangothi kunye nokuhlamba
Emva kokuba ukusabela kugqityiwe, inkqubo isenayo i-alkali engaphendulwanga, i-solvent kunye neemveliso (ezifana ne-NaCl). Ke ngoko, ukungathathi hlangothi kunye nokuhlamba kuyafuneka:
I-Neutralization: Sebenzisa i-asidi (efana ne-acetic acid) ukuze unciphise i-alkali kwinkqubo kwaye ulungelelanise ixabiso le-pH kwi-6-8.
Ukuhlamba: Sebenzisa ubuninzi bamanzi ashushu okanye i-ethanol isisombululo se-aqueous ukuhlamba ngokuphindaphindiweyo i-cellulose ukususa izinto ezingenakulinganiswa kunye neemveliso, ukunciphisa umxholo wokungcola, kunye nokuphucula ukucoceka kwemveliso.
1.5 Ukomisa kunye nokutyumza
Emva kokuhlamba, i-HEMC isenomswakama ophezulu kwaye kufuneka yomiswe. Iindlela zokomisa eziqhelekileyo zezi:
Ukomisa ukuhamba komoya: ukusebenzisa umoya oshushu ohamba ngesantya esiphezulu ukomisa i-HEMC emanzi, ngokusebenza okuphezulu kunye nokufanelekileyo kwimveliso enkulu.
Ukomisa i-vacuum: ukufudumeza kunye nokumisa phantsi kwemeko ephantsi yoxinzelelo, enokuthintela ngokufanelekileyo ukuthotywa kwe-cellulose kwaye ifanelekile kwiimveliso eziphezulu.
Emva kokumisa, i-HEMC ichithwa yi-pulverizer kwaye ubukhulu be-particle bulawulwa ngokuhlolwa ukuze kufezekiswe ubuncinci obufunekayo bemveliso (ngokuqhelekileyo i-80-120 mesh).
2. Ulawulo lomgangatho
Ulawulo lomgangatho we-HEMC ikakhulu lubandakanya ezi zalathisi zilandelayo:
IDegree of substitution (DS kunye ne-MS): imisela ukunyibilika kunye ne-viscosity, ngokubanzi i-DS iphakathi kwe-1.1-2.0 kunye ne-MS phakathi kwe-0.1-0.5.
Umxholo wokufuma: ngokuqhelekileyo kufuneka ube≤5%.
I-Viscosity: amabakala ahlukeneyo e-viscosity ayadingeka kwiinkalo ezahlukeneyo zesicelo (ezifana ne-400-100,000 mPa·s).
Ukucoceka: kufuna umxholo wothuthu oluphantsi, ukususwa kwezinyibilikisi ezishiyekileyo, kunye nokuqinisekisa ukuba akukho vumba.
3. Iindawo zesicelo eziphambili
Izinto zokwakha: ezisetyenziselwa udaka lwesamente, i-putty powder, i-adhesive tile, ukuphucula ukugcinwa kwamanzi kunye nokusebenza kokwakhiwa.
Umzi-mveliso wokugquma: usetyenziswa kwipeyinti ye-latex kunye nepeyinti, ukubonelela nge-rheology elungileyo kunye nokusebenza okuchasayo.
Amayeza kunye nokutya: njenge-thickener kunye ne-emulsifier, ngokuhambelana nebakala lokutya okanye imigangatho ye-pharmacopoeia.
IHEMC inkqubo yokuvelisa ibandakanya i-alkalization, i-etherification, i-neutralization, ukuhlamba, ukomisa kunye nokutyumza. Ukuphucula iiparamitha zenkqubo kunye nokuphucula idigri yokutshintshwa kunye nokucoceka kwemveliso zizitshixo zokuphucula ukusebenza kwe-HEMC. Ngokunyuka kweemfuno zokukhuselwa kwendalo kunye nokuveliswa kohlaza, imveliso ye-HEMC iya kuhlawula ngakumbi ukugcinwa kwamandla kunye nokunciphisa ukukhutshwa kunye nokusetyenziswa kwe-solvents eluhlaza kwixesha elizayo.
Ixesha lokuposa: May-08-2025