Iimpembelelo zaBantu ababambeleyo kunye nobunzima beMolekyuli kwiiPropati eziMphezulu ze-Nonionic Cellulose Ether

Ngokwe theory kaWashburn's impregnation (iTheory yePenetration) kunye nethiyori edityanisiweyo kaVan Oss-Good-Chaudhury (Ithiyori eDityanisiweyo) kunye nokusetyenziswa kwetekhnoloji ye-columnar wick (iColumn Wicking Technique), ii-ethers ezininzi ze-non-ionic cellulose, ezifana ne-methyl cellulose. i-cellulose, i-hydroxypropyl cellulose kunye ne-hydroxypropyl methylcellulose zavavanywa. Ngenxa yezinto ezithatha indawo ezahlukeneyo, iidigri zokutshintsha kunye nobunzima beemolekyuli zezi ether ze-cellulose, amandla abo angaphezulu kunye namalungu azo ahluke kakhulu. Idatha ibonisa ukuba isiseko se-Lewis se-non-ionic cellulose ether inkulu kune-Lewis acid, kwaye inxalenye ephambili ye-surface yamandla akhululekile yi-Lifshitz-van der Waals force. Amandla angaphezulu e-hydroxypropyl kunye nokwakheka kwawo kukhulu kune-hydroxymethyl. Ngaphantsi kwesiseko sendawo enye kunye neqondo lokutshintshwa, amandla angaphandle akhululekile e-hydroxypropyl cellulose alingana nobunzima be-molecular; ngelixa i-surface yamandla ekhululekile ye-hydroxypropyl methylcellulose ilingana neqondo lokutshintshwa kunye nokulinganisa ngokuphambeneyo kubunzima bemolekyuli. Uvavanyo lukwafumanise ukuba amandla angaphezulu e-hydroxypropyl kunye ne-hydroxypropylmethyl kwi-non-ionic cellulose ether abonakala emkhulu kunamandla angaphezulu e-cellulose, kwaye uvavanyo lungqina ukuba amandla angaphezulu e-cellulose evavanyiweyo kunye nokwakheka kwayo. ihambelana noncwadi.

Amagama angundoqo: i-nonionic cellulose ethers; ababambeleyo kunye nezidanga zokutshintsha; ubunzima bemolekyuli; iipropati zomphezulu; iteknoloji yocingo

I-ether ye-cellulose luhlu olukhulu lwee-cellulose derivatives, ezinokuthi zihlulwe zibe yi-anionic, i-cationic kunye ne-nonionic ethers ngokwesakhiwo sekhemikhali se-ether substituents yazo. I-ether ye-Cellulose yenye yeemveliso zokuqala eziphandwe kwaye zaveliswa kwi-polymer chemistry. Ukuza kuthi ga ngoku, i-cellulose ether isetyenziswe ngokubanzi kumayeza, ucoceko, izimonyo kunye neshishini lokutya.

Nangona i-cellulose ethers, efana ne-hydroxymethylcellulose, i-hydroxypropylcellulose kunye ne-hydroxypropylmethylcellulose, ziye zaveliswa kwimizi-mveliso kwaye ezininzi zeepropathi zazo ziye zafundwa, amandla abo angaphezulu, i-asidi ye-Alkali-reactive properties ayizange ichazwe ngoku. Ekubeni uninzi lwezi mveliso zisetyenziswa kwindawo engamanzi, kunye neempawu zomphezulu, ngakumbi iimpawu zokusabela kwe-asidi-base, zinokuchaphazela ukusetyenziswa kwazo, kubaluleke kakhulu ukufunda nokuqonda iimpawu zeekhemikhali zomphezulu zolurhwebo lwe-ether cellulose.

Ukuqwalasela ukuba iisampulu ze-cellulose derivatives zilula kakhulu ukutshintsha kunye nokutshintsha kweemeko zokulungiselela, eli phepha lisebenzisa iimveliso zorhwebo njengeisampulu zokubonakalisa amandla abo angaphezulu, kwaye ngokusekelwe kule nto, impembelelo yababambeli kunye nobunzima beemolekyuli zeemveliso ezinjalo kumphezulu. iipropati ziyafundwa.

1. Inxalenye yovavanyo

1.1 Iimathiriyeli ekrwada

I-ether ye-cellulose engekho i-ionic esetyenziswe kuvavanyo yimveliso yeKIMA CHEMICAL CO.,LTD,. Iisampuli azizange zifakwe kulo naluphi na unyango phambi kovavanyo.

Ukuqwalasela ukuba i-cellulose derivatives yenziwe nge-cellulose, izakhiwo ezibini zisondele, kwaye iimpawu ezingaphezulu ze-cellulose zichazwe kwiincwadi, ngoko eli phepha lisebenzisa i-cellulose njengesampuli eqhelekileyo. Isampulu yeselulosi esetyenzisiweyo yayiyikhowudi ebizwa ngokuba yi-C8002 kwaye yathengwa kuyoKIMA, CN. Isampuli ayizange ifakwe naluphi na unyango ngexesha lovavanyo.

Izinto ezisetyenziswayo kuvavanyo zezi: ethane, diiodomethane, deionized water, formamide, toluene, chloroform. Lonke ulwelo lwaluzimveliso ezisulungekileyo ngokohlalutyo ngaphandle kwamanzi awayefumaneka kurhwebo.

1.2 Indlela yovavanyo

Kulo mvavanyo, ubuchule bokukhwabanisa ikholomu yamkelwa, kwaye icandelo (malunga ne-10 cm) ye-pipette eqhelekileyo kunye nobubanzi obungaphakathi be-3 mm yanqunyulwa njenge-tube yekholomu. Beka i-200 mg yesampuli engumgubo kwityhubhu yekholomu ngexesha ngalinye, emva koko uyishukumise ukuze ilingane kwaye uyibeke ngokuthe nkqo emazantsi esitya seglasi kunye nedayamitha engaphakathi emalunga ne-3 cm, ukuze ulwelo lukwazi ukubhengezwa ngokuzenzekelayo. Yenza umlinganiselo we-1 mL yolwelo oluza kuvavanywa kwaye ulufake kwisikhongozeli seglasi, kwaye urekhode ixesha lokuntywiliselwa kunye nomgama wokuntywilisela X ngaxeshanye. Zonke iimvavanyo zenziwa kubushushu begumbi (25±1°C). Idatha nganye yi-avareji yophindaphindo lwemifuniselo emithathu.

1.3 Ukubalwa kwedatha yovavanyo

Isiseko sethiyori sokusetyenziswa kobuchule bokwenza ikholamu yokuvavanya amandla angaphezulu omgubo wemathiriyeli yi-Washburn impregnation equation (i-Washburn penetration equation).

1.3.1 Ukumiselwa kweradiyasi esebenzayo ye-capillary Reff yesampulu elinganisiweyo

Xa usebenzisa ifomula yokuntywiliselwa kweWashburn, imeko yokufikelela ukumanzisa okupheleleyo yi-cos=1. Oku kuthetha ukuba xa ulwelo lukhethwa ukuba luntywiliselwe kwisiqina ukuze sifezekise imeko emanzi ngokupheleleyo, sinokubala i-capillary radius esebenzayo Reff yesampulu elinganisiweyo ngokuvavanya umgama wokuntywiliselwa kunye nexesha ngokwemeko ekhethekileyo ye-Washburn immersion formula.

1.3.2 Lifshitz-van der Waals ukubalwa kwamandla kwisampulu elinganisiweyo

Ngokukavan Oss-Chaudhury-Good's edibanisa imithetho, ubudlelwane phakathi kweempendulo phakathi kolwelo kunye nezinto eziqinileyo.

1.3.3 Ukubalwa kwe-Lewis acid-base force yeesampuli ezilinganisiweyo

Ngokubanzi, iipropathi ze-acid-base of solids ziqikelelwa kwidatha efakwe emanzini kunye ne-formamide. Kodwa kweli nqaku, sifumene ukuba akukho ngxaki xa usebenzisa le sibini ye-polar liquids ukulinganisa i-cellulose, kodwa kuvavanyo lwe-cellulose ether, kuba ukuphakama kokuntywiliselwa kwenkqubo yesisombululo se-polar yamanzi / i-formamide kwi-cellulose ether iphantsi kakhulu. , ukwenza ixesha lokurekhoda kube nzima kakhulu. Ngoko ke, inkqubo yesisombululo se-toluene / chloroform eyaziswa yiChibowsk yakhethwa. Ngokutsho kweChibowski, inkqubo yesisombululo se-toluene / chloroform polar nayo iyindlela yokukhetha. Oku kungenxa yokuba ezi zilwelo zimbini zineasidi ekhethekileyo kunye nealkalinity, umzekelo, itoluene ayinayo i-Lewis acidity, kwaye i-chloroform ayinayo i-Lewis alkalinity. Ukuze ufumane idatha efunyenwe yinkqubo yesisombululo se-toluene / chloroform kufuphi nenkqubo yesisombululo se-polar esicetyiswayo samanzi / i-formamide, sisebenzisa ezi nkqubo zimbini ze-polar zolwelo ukuvavanya i-cellulose ngexesha elinye, kwaye emva koko sifumane ukwandiswa okuhambelanayo okanye ukucutha i-coefficients. ngaphambi kokufaka idatha efunyenwe ngokufaka i-cellulose ether kunye ne-toluene / i-chloroform isondele kwizigqibo ezifunyenwe kumanzi / inkqubo ye-formamide. Ekubeni i-cellulose ethers ivela kwi-cellulose kwaye kukho isakhiwo esifanayo kakhulu phakathi kwezi zimbini, le ndlela yoqikelelo inokusebenza.

1.3.4 Ukubalwa kwamandla asimahla angaphezulu

2. Iziphumo kunye neNgxoxo

2.1 umgangatho weSelulosi

Ekubeni iziphumo zethu zovavanyo kwiisampuli eziqhelekileyo zeselulosi zifumene ukuba ezi datha zihambelana kakuhle nezo zichazwe kuncwadi, kunengqiqo ukukholelwa ukuba iziphumo zovavanyo kwi-cellulose ethers kufuneka ziqwalaselwe.

2.2 Iziphumo zovavanyo kunye neengxoxo ze-cellulose ether

Ngexesha lovavanyo lwe-cellulose ether, kunzima kakhulu ukurekhoda umgama wokucwiliswa kunye nexesha ngenxa yobude obuphantsi kakhulu bokuntywiliselwa kwamanzi kunye ne-formamide. Ngoko ke, eli phepha likhetha inkqubo yesisombululo se-toluene / chloroform njengesisombululo esisesinye, kwaye iqikelela i-Lewis acidity ye-cellulose ether ngokusekelwe kwiziphumo zovavanyo lwamanzi / i-formamide kunye ne-toluene / i-chloroform kwi-cellulose kunye nobudlelwane obulinganayo phakathi kweenkqubo ezimbini zesisombululo. kunye namandla ealkaline.

Ukuthatha i-cellulose njengesampuli eqhelekileyo, uluhlu lweempawu ze-acid-base ze-cellulose ethers zinikezelwa. Ekubeni isiphumo sokukhulelwa kwe-cellulose ether nge-toluene/chloroform ivavanywa ngokuthe ngqo, iyaqinisekisa.

Oku kuthetha ukuba uhlobo kunye nobunzima be-molecular of substituents buchaphazela iimpawu ze-acid-base ze-cellulose ether, kunye nobudlelwane phakathi kwezinto ezimbini, i-hydroxypropyl kunye ne-hydroxypropylmethyl, kwiipropati ze-acid-base ze-cellulose ether kunye ne-molecular weight ngokuchasene ngokupheleleyo. Kodwa isenokunxulunyaniswa nento yokuba amaLungu ePalamente ngamaqela axubileyo.

Kuba izinto ezithatha indawo ye-MO43 kunye ne-K8913 zahlukile kwaye zinobunzima obufanayo bemolekyuli, umzekelo, indawo yangaphambili yi-hydroxymethyl kwaye indawo yokugqibela yi-hydroxypropyl, kodwa ubunzima bemolekyuli zombini yi-100,000, ngoko oko kuthetha ukuba Isiseko sobunzima be-molecular efanayo Ngaphantsi kweemeko, i-S + kunye ne-S- yeqela le-hydroxymethyl ingaba yincinci kuneqela le-hydroxypropyl. Kodwa iqondo lokutshintshwa kwakhona kunokwenzeka, kuba iqondo lokutshintshwa kwe-K8913 limalunga ne-3.00, ngelixa le-MO43 yi-1.90 kuphela.

Ekubeni i-degree of substitution and substitutes of K8913 kunye ne-K9113 iyafana kodwa ubunzima be-molecular kuphela buhluke, ukuthelekisa phakathi kwezi zibini kubonisa ukuba i-S + ye-hydroxypropyl cellulose iyancipha ngokunyuka kwe-molecular weight, kodwa i-S- iyanda ngokuchaseneyo. .

Ukususela kwisishwankathelo seziphumo zovavanyo lwamandla omphezulu wazo zonke ii-ether ze-cellulose kunye namalungu azo, kunokubonwa ukuba ingaba yi-cellulose okanye i-cellulose ether, icandelo eliphambili lamandla abo angaphezulu yi-Lifshitz-van der Waals force, i-accounting for malunga ne-98% ~ 99%. Ngaphezu koko, i-Lifshitz-van der Waals imikhosi ye-nonionic cellulose ethers (ngaphandle kwe-MO43) nayo ininzi kakhulu kune-cellulose, ebonisa ukuba inkqubo ye-etherification ye-cellulose ikwayinkqubo yokwandisa amandla e-Lifshitz-van der Waals. Kwaye oku kunyuka kukhokelela kumandla omphezulu we-cellulose ether abe mkhulu kuneselulosi. Le nto inomdla kakhulu kuba ezi ether ze-cellulose zisetyenziswa ngokuqhelekileyo kwimveliso ye-surfactants. Kodwa idatha iyaphawuleka, kungekuphela nje ngenxa yokuba idatha malunga nesampulu yomgangatho wesalathiso evavanyiweyo kolu vavanyo ihambelana kakhulu nexabiso elichazwe kuncwadi, idatha malunga nesampulu yomgangatho wesalathiso ihambelana kakhulu nexabiso elixelwe kuncwadi, kuba umzekelo: zonke ezi cellulose I-SAB ye-ethers incinci kakhulu kune-cellulose, kwaye oku kungenxa yeziseko zabo ezinkulu ze-Lewis. Ngaphantsi kwesiseko sendawo enye kunye neqondo lokutshintshwa, amandla angaphandle akhululekile e-hydroxypropyl cellulose alingana nobunzima be-molecular; ngelixa i-surface yamandla ekhululekile ye-hydroxypropyl methylcellulose ilingana neqondo lokutshintshwa kunye nokulinganisa ngokuphambeneyo kubunzima bemolekyuli.

Ukongeza, ngenxa yokuba i-cellulose ethers ine-SLW enkulu kune-cellulose, kodwa sele sisazi ukuba i-dispersibility yabo ingcono kuneselulosi, ngoko kunokuqwalaselwa kwangaphambili ukuba icandelo eliphambili le-SLW elibandakanya i-nonionic cellulose ethers kufuneka ibe yi-London force.

3. Isiphelo

Uphononongo lubonise ukuba uhlobo lwe-substitute, i-degree of substitution kunye ne-molecular weight inefuthe elikhulu kumandla omhlaba kunye nokubunjwa kwe-non-ionic cellulose ether. Kwaye esi siphumo sibonakala sinesiqhelo silandelayo:

(1) I-S+ ye-non-ionic cellulose ether incinci kune-S-.

(2) Amandla angaphezulu e-nonionic cellulose ether alawulwa yi-Lifshitz-van der Waals force.

(3) Ubunzima bemolekyuli kunye nezinto ezibambeleyo zinefuthe kumandla omphezulu we-non-ionic cellulose ethers, kodwa ubukhulu becala kuxhomekeke kuhlobo lwababambeleyo.

(4) Phantsi kwesiseko sendawo enye kunye nenqanaba lokutshintsha, amandla angaphezulu asimahla e-hydroxypropyl cellulose alingana nobunzima bemolekyuli; ngelixa i-surface yamandla ekhululekile ye-hydroxypropyl methylcellulose ilingana neqondo lokutshintshwa kunye nokulinganisa ngokuphambeneyo kubunzima bemolekyuli.

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