Focus on Cellulose ethers

I-Synthesis kunye ne-Rheological Properties ye-Hydroxyethyl Cellulose Ether

I-Synthesis kunye ne-Rheological Properties ye-Hydroxyethyl Cellulose Ether

Phambi kwe-alkali catalyst eyenziwe ngokwayo, i-industrial hydroxyethyl i-cellulose yaphendulwa nge-N-(2,3-epoxypropyl) trimethylammonium chloride (GTA) cationization reagent ukuze kulungiswe i-high-substitution ye-quaternary ammonium ngendlela eyomileyo Uhlobo lwetyuwa iHydroxyethyl cellulose ether (I-HEC).Iziphumo zomlinganiselo we-GTA ukuya kwi-hydroxyethyl cellulose (HEC), umlinganiselo we-NaOH ukuya kwi-HEC, ubushushu bokuphendula, kunye nexesha lokuphendula kwi-activity ye-reaction yaphandwa ngesicwangciso sokulinga esifanayo, kunye neemeko zenkqubo eziphuculweyo zafunyanwa nge-Monte. Carlo ukulinganisa.Kwaye ukusebenza kakuhle kwe-reagent ye-cationic etherification ifikelela kwi-95% ngokuqinisekiswa kovavanyo.Ngelo xesha, iimpawu zayo ze-rheological zaxoxwa.Iziphumo zabonisa ukuba isisombululo seI-HEC ibonise iimpawu ze-non-Newtonian fluid, kunye ne-viscosity yayo ebonakalayo yanda ngokunyuka kwesisombululo sobuninzi besisombululo;kugxininiso oluthile lwesisombululo setyuwa, i-viscosity ebonakalayo yeI-HEC yehla ngokunyuka kwetyuwa eyongeziweyo.Ngaphantsi komlinganiselo ofanayo wokucheba, i-viscosity ebonakalayo yeI-HEC kwinkqubo yesisombululo yeCaCl2 iphezulu kunaleyo yeI-HEC kwinkqubo yesisombululo seNaCl.

Amagama angundoqo:IHydroxyethyli-cellulose ether;inkqubo eyomileyo;iimpawu zerheological

 

I-Cellulose ineempawu zemithombo ecebileyo, i-biodegradability, i-biocompatibility kunye ne-derivatization elula, kwaye iyindawo yophando kwiinkalo ezininzi.I-Cationic cellulose yenye yezona zinto zibalulekileyo zabameli be-cellulose derivatives.Phakathi kweepolymers ze-cationic kwiimveliso zokukhusela ezibhaliswe yi-CTFA ye-Fragrance Industry Association, ukusetyenziswa kwayo ngowokuqala.Inokusetyenziswa ngokubanzi kwizongezo zokulungisa imeko yeenwele, izithambiso, ukugrumba i-shale hydration inhibitors kunye ne-blood anti-coagulation agents kunye nezinye iindawo.

Okwangoku, indlela yokulungiselela i-quaternary ammonium cationic hydroxyethyl cellulose ether yindlela yokunyibilikisa, efuna isixa esikhulu se-solvents eziphilayo ezibizayo, zibiza, azikhuselekanga, kwaye zingcolisa indalo.Xa kuthelekiswa nendlela yokunyibilikisa, indlela eyomileyo ineenzuzo ezibalaseleyo zenkqubo elula, ukusebenza kakuhle kokusabela, kunye nokungcoliseka okuncinci kokusingqongileyo.Kweli phepha, i-cationic cellulose ether yenziwe ngendlela eyomileyo kwaye ukuziphatha kwayo kwe-rheological kwafundwa.

 

1. Inxalenye yovavanyo

1.1 Izixhobo kunye nee-reagents

I-Hydroxyethyl cellulose (imveliso ye-HEC yoshishino, idigri yayo ye-molecular substitution DS yi-1.8 ~ 2.0);i-cationization reagent N-(2,3-epoxypropyl) trimethylammonium chloride (GTA), elungiswe kwi-epoxy chloride Propane kunye ne-trimethylamine zizenzele phantsi kweemeko ezithile;i-alkali catalyst eyenziwe ngokwayo;i-ethanol kunye ne-glacial acetic acid zihlalutye zihlambulukile;I-NaCl, i-KCl, i-CaCl2, kunye ne-AlCl3 zii-reagents ezicocekileyo zemichiza.

1.2 Ukulungiswa kwe-quaternary ammonium cationic cellulose

Yongeza i-5g ye-hydroxyethyl cellulose kunye nenani elifanelekileyo le-alkali catalyst eyenziwe ekhaya kwi-cylindrical steel cylinder exhotywe nge-stirrer, kwaye ugxobhoze imizuzu engama-20 kwiqondo lokushisa;emva koko wongeze inani elithile le-GTA, qhubeka ushukumisa imizuzu engama-30 kwiqondo lobushushu begumbi, kwaye usabele kwiqondo lobushushu elithile kunye nexesha, imveliso ekrwada eyomeleleyo ngokusisiseko ifunyenwe.Imveliso ekrwada ifakwe kwisisombululo se-ethanol esiqulethe isixa esifanelekileyo se-acetic acid, ihluziwe, ihlanjwe, kunye ne-vacuum-yomiswa ukufumana i-quaternary ammonium cationic cellulose engumgubo.

1.3 Ukumiselwa kweqhezu lobunzima benitrogen yequaternary ammonium cationic hydroxyethyl cellulose

Ubuninzi beqhekeza le-nitrogen kwiisampulu zagqitywa yindlela ye-Kjeldahl.

 

2. Uyilo lovavanyo kunye nokulungiswa kwenkqubo yokudibanisa okomileyo

Indlela yokuyila efanayo yayisetyenziselwa ukuyila umfuniselo, kunye nemiphumo yomlinganiselo we-GTA kwi-hydroxyethyl cellulose (HEC), umlinganiselo we-NaOH ukuya kwi-HEC, ubushushu bokuphendula kunye nexesha lokuphendula kwi-reaction performance yaphandwa.

 

3. Uphando kwiimpawu ze-rheological

3.1 Impembelelo yokugxila kunye nesantya sokujikeleza

Ukuthatha impembelelo yesantya sokucheba kwi-viscosity ebonakalayo yeI-HEC kwiindawo ezahlukeneyo ze-Ds=0.11 njengomzekelo, kunokubonwa ukuba njengoko izinga lokucheba linyuka ngokuthe ngcembe ukusuka ku-0.05 ukuya kwi-0.5 s-1, i-viscosity ebonakalayo yeI-HEC isisombululo siyancipha, ngakumbi kwi-0.05 ~ 0.5s-1 i-viscosity ebonakalayo yehla ngokukhawuleza ukusuka kwi-160MPa·s ukuba 40MPa·s, ukucheba ukucheba, ebonisa ukubaI-HEC isisombululo samanzi sibonise iipropati ezingezo-Newtonian rheological.Umphumo woxinzelelo lwe-shear osetyenzisiweyo kukunciphisa amandla okusebenzisana phakathi kweengqungquthela zesigaba esihlakaziweyo.Ngaphantsi kweemeko ezithile, amandla amakhulu, ngakumbi i-viscosity ebonakalayo.

Ingabonwa kwakhona kwi-viscosities ebonakalayo ye-3% kunye ne-4%I-HEC izisombululo ezinamanzi ukuba ukugxininiswa kobunzima ngokulandelelanayo yi-3% kunye ne-4% kumazinga ahlukeneyo okucheba.I-viscosity ebonakalayo yesisombululo ibonisa ukuba amandla ayo okwandisa i-viscosity ayanda kunye noxinaniso.Isizathu kukuba njengoko uxinaniso lukhula kwinkqubo yesisombululo, ukunyathelana phakathi kweemolekyuli zekhonkco eliphambili.I-HEC kwaye phakathi kwamatyathanga eemolekyuli ayanda, kwaye i-viscosity ebonakalayo iyanda.

3.2 Ifuthe leetyuwa ezidityanisiweyo ezahlukeneyo

Ugxininiso lweI-HEC yalungiswa kwi-3%, kwaye umphumo wokongeza ityuwa ye-NaCl kwiipropati ze-viscosity zesisombululo zaphandwa kumazinga ahlukeneyo e-shear.

Inokubonwa kwiziphumo ukuba i-viscosity ebonakalayo iyancipha ngokunyuka kwe-concentration yetyuwa eyongezelelweyo, ebonisa i-polyelectrolyte phenomenon ecacileyo.Oku kungenxa yokuba inxalenye yeNa + kwisisombululo setyuwa ibotshelelwe kwianion yeI-HEC ikhonkco elisecaleni.Okukhona ukuxinana kwesisombululo setyuwa, kokukhona iqondo lokungakhethi cala okanye ukukhuselwa kwepolyyoni nge-counterion, kunye nokuncipha kwe-electrostatic repulsion, okukhokelela ekunciphiseni koxinzelelo lwentlawulo yepolyyoni., i-polymer chain iyancipha kwaye i-curls, kwaye i-concentration ebonakalayo iyancipha.

3.3 Ifuthe leetyuwa ezahlukeneyo ezongeziweyo

Inokubonwa kwimpembelelo yeetyuwa ezimbini ezahlukeneyo ezongeziweyo, i-Nacl kunye ne-CaCl2, kwi-viscosity ebonakalayo ye.I-HEC isisombululo sokuba i-viscosity ebonakalayo iyancipha ngokudibanisa ityuwa eyongezelelweyo, kwaye kwinqanaba elifanayo lokucheba, i-viscosity ebonakalayo yeI-HEC isisombululo kwinkqubo yesisombululo seCaCl2 I-viscosity ebonakalayo iphezulu kakhulu kunolo lweI-HEC isisombululo kwinkqubo yesisombululo seNaCl.Isizathu kukuba ityuwa ye-calcium yi-ion ye-divalent, kwaye kulula ukuyibopha kwi-Cl-ye-polyelectrolyte side chain.Indibaniselwano yeqela le quaternary ammonium kwiI-HEC nge Cl- kuncitshiswe, kunye nokhuselo luncinci, kwaye ingxinano yentlawulo ye-polymer chain iphezulu, okubangela I-electrostatic repulsion kwi-polymer chain inkulu, kunye nekhonkco yepolymer yoluliwe, ngoko i-viscosity ebonakalayo iphezulu.

 

4. Isiphelo

Ukulungiswa okomileyo kwe-cationic cellulose efakwe endaweni ephezulu yindlela efanelekileyo yokulungiselela kunye nokusebenza okulula, ukusebenza kakuhle kokuphendula, kunye nongcoliseko oluncinci, kwaye inokuphepha ukusetyenziswa kwamandla aphezulu, ukungcoliseka kwendalo, kunye netyhefu ebangelwa ukusetyenziswa kwezinyibilikisi.

Isisombululo se-cationic cellulose ether sibonisa iimpawu ze-non-Newtonian fluid kwaye zineempawu zokuqhawula i-shear;njengoko i-concentration mass concentration inyuka, i-viscosity yayo ebonakalayo iyanda;kwingxubusho ethile yesisombululo setyuwa,I-HEC i-viscosity ebonakalayo iyanda ngokunyuka kunye nokuncipha.Ngaphantsi komlinganiselo ofanayo wokucheba, i-viscosity ebonakalayo yeI-HEC kwinkqubo yesisombululo yeCaCl2 iphezulu kunaleyo yeI-HEC kwinkqubo yesisombululo seNaCl.


Ixesha lokuposa: Feb-27-2023
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