Qhov cuam tshuam ntawm cov khoom hloov pauv thiab qhov hnyav ntawm molecular ntawm cov khoom siv ntawm Nonionic Cellulose Ether

Raws li Washburn's impregnation theory (Penetration Theory) thiab van Oss-Good-Chaudhury txoj kev sib xyaw ua ke (Combining Theory) thiab daim ntawv thov ntawm columnar wick thev naus laus zis (Kem Wicking Technique), ntau yam uas tsis yog-ionic cellulose ethers, xws li methyl cellulose. cellulose, hydroxypropyl cellulose thiab hydroxypropyl methylcellulose tau sim. Vim muaj cov khoom sib txawv, qib kev hloov pauv thiab qhov hnyav molecular ntawm cov cellulose ethers, lawv lub zog saum npoo thiab lawv cov khoom sib txawv heev. Cov ntaub ntawv qhia tau hais tias Lewis lub hauv paus ntawm non-ionic cellulose ether yog loj dua Lewis acid, thiab lub ntsiab tivthaiv ntawm lub saum npoo dawb zog yog Lifshitz-van der Waals quab yuam. Lub zog saum npoo ntawm hydroxypropyl thiab nws cov muaj pes tsawg leeg yog ntau dua li ntawm hydroxymethyl. Nyob rau hauv lub premise ntawm tib lub substituent thiab degree ntawm kev hloov, lub nto dawb zog ntawm hydroxypropyl cellulose yog proportional rau lub molecular hnyav; thaum lub zog tsis muaj zog ntawm hydroxypropyl methylcellulose yog proportional rau qhov kev hloov pauv thiab inversely proportional rau qhov hnyav molecular. Qhov kev sim kuj pom tau tias lub zog saum npoo ntawm qhov hloov pauv hydroxypropyl thiab hydroxypropylmethyl nyob rau hauv cov non-ionic cellulose ether zoo li ntau dua li lub zog saum npoo ntawm cellulose, thiab qhov kev sim ua pov thawj tias lub zog saum npoo ntawm cov cellulose kuaj thiab nws cov ntaub ntawv yog raws li cov ntaub ntawv.

Cov lus tseem ceeb: nonionic cellulose ethers; hloov pauv thiab qib hloov pauv; molecular hnyav; nto khoom; wick technology

Cellulose ether yog ib pawg loj ntawm cellulose derivatives, uas tuaj yeem muab faib ua anionic, cationic thiab nonionic ethers raws li cov qauv tshuaj ntawm lawv cov ether substituents. Cellulose ether kuj yog ib qho ntawm cov khoom lag luam ntxov tshaj plaws tshawb fawb thiab tsim hauv polymer chemistry. Txog tam sim no, cellulose ether tau siv dav hauv tshuaj, tu cev, tshuaj pleev ib ce thiab kev lag luam zaub mov.

Txawm hais tias cellulose ethers, xws li hydroxymethylcellulose, hydroxypropylcellulose thiab hydroxypropylmethylcellulose, tau tsim muaj kev lag luam thiab ntau ntawm lawv cov khoom tau kawm, lawv lub zog nto, acid Alkali-reactive zog tsis tau tshaj tawm txog tam sim no. Txij li thaum feem ntau ntawm cov khoom siv no yog siv nyob rau hauv ib puag ncig ua kua, thiab cov yam ntxwv saum npoo, tshwj xeeb tshaj yog cov kua qaub-puag cov tshuaj tiv thaiv cov yam ntxwv, yuav muaj feem cuam tshuam rau lawv txoj kev siv, nws yog ib qho tsim nyog yuav tsum tau kawm thiab nkag siab txog cov yam ntxwv ntawm cov khoom lag luam cellulose ether.

Xav txog tias cov qauv ntawm cov cellulose derivatives yog qhov yooj yim heev los hloov nrog kev hloov ntawm kev npaj, daim ntawv no siv cov khoom lag luam raws li cov qauv los qhia lawv lub zog saum npoo, thiab raws li qhov no, kev cuam tshuam ntawm kev hloov pauv thiab qhov hnyav molecular ntawm cov khoom zoo li no rau ntawm qhov chaw. cov khoom yog kawm.

1. Kev sim ib feem

1.1 Cov khoom siv raw

Cov non-ionic cellulose ether siv hauv kev sim yog cov khoom ntawmKIMA CHEMICAL CO., LTD,. Cov qauv no tsis raug rau kev kho mob ua ntej kuaj.

Xav tias cellulose derivatives yog ua los ntawm cellulose, ob lub qauv yog nyob ze, thiab cov khoom nto ntawm cellulose tau tshaj tawm nyob rau hauv cov ntaub ntawv, yog li daim ntawv no siv cellulose raws li tus qauv qauv. Cov qauv cellulose siv yog code-npe C8002 thiab tau yuav los ntawmKIMA, CN. Cov qauv no tsis raug rau kev kho mob thaum lub sijhawm kuaj.

Cov reagents siv hauv kev sim yog: ethane, diiodomethane, deionized dej, formamide, toluene, chloroform. Tag nrho cov kua tau tshuaj xyuas cov khoom ntshiab tsuas yog dej uas muaj muag.

1.2 Kev sim txoj kev

Hauv qhov kev sim no, cov txheej txheem kem wicking tau saws, thiab ib ntu (kwv yees li 10 cm) ntawm tus qauv pipette nrog ib txoj kab uas hla ntawm 3 hli raug txiav raws li cov kab kem. Muab 200 mg ntawm hmoov coj mus rau hauv kem raj txhua lub sij hawm, ces co nws kom nws txawm thiab muab nws ntsug rau hauv qab ntawm lub khob ntim nrog ib lub cheeb ntawm txog 3 cm, thiaj li hais tias cov kua yuav adsorbed spontaneously. Qhov hnyav 1 mL ntawm cov kua yuav tsum tau kuaj thiab muab tso rau hauv lub khob ntim, thiab sau lub sij hawm immersion t thiab immersion nrug X tib lub sijhawm. Txhua qhov kev sim tau ua nyob rau hauv chav tsev kub (25±1°C). Txhua cov ntaub ntawv yog qhov nruab nrab ntawm peb qhov kev sim rov ua dua.

1.3 Kev suav cov ntaub ntawv sim

Lub hauv paus theoretical rau kev siv cov txheej txheem kem wicking los kuaj lub zog saum npoo ntawm cov ntaub ntawv hmoov yog Washburn impregnation equation (Washburn penetration equation).

1.3.1 Kev txiav txim siab ntawm capillary zoo radius Reff ntawm cov qauv ntsuas

Thaum ua ntawv thov Washburn immersion mis, tus mob rau kev ua tiav wetting yog cos = 1. Qhov no txhais tau hais tias thaum cov kua raug xaiv los raus rau hauv cov khoom kom ua tiav qhov ntub dej tag nrho, peb tuaj yeem suav cov capillary zoo radius Reff ntawm cov qauv ntsuas los ntawm kev ntsuas qhov immersion nrug thiab lub sijhawm raws li qhov tshwj xeeb ntawm Washburn immersion formula.

1.3.2 Lifshitz-van der Waals quab yuam xam rau cov qauv ntsuas

Raws li van Oss-Chaudhury-Good txoj kev sib xyaw ua ke, kev sib raug zoo ntawm cov tshuaj tiv thaiv ntawm cov kua thiab cov khib nyiab.

1.3.3 Kev suav ntawm Lewis acid-base quab yuam ntawm cov qauv ntsuas

Feem ntau, cov kua qaub-puag khoom ntawm cov khib nyiab yog kwv yees los ntawm cov ntaub ntawv impregnated nrog dej thiab formamide. Tab sis nyob rau hauv tsab xov xwm no, peb pom tias tsis muaj teeb meem thaum siv ob lub polar kua los ntsuas cellulose, tab sis nyob rau hauv qhov kev ntsuam xyuas ntawm cellulose ether, vim hais tias lub immersion qhov siab ntawm lub polar tov system ntawm dej / formamide nyob rau hauv cellulose ether yog tsawg heev. , ua rau lub sijhawm sau ntawv nyuaj heev. Yog li ntawd, cov tshuaj toluene / chloroform qhia los ntawm Chibowsk raug xaiv. Raws li Chibowski, toluene / chloroform polar tov system kuj yog ib qho kev xaiv. Qhov no yog vim tias ob cov kua dej no muaj cov kua qaub tshwj xeeb thiab alkalinity, piv txwv li, toluene tsis muaj Lewis acidity, thiab chloroform tsis muaj Lewis alkalinity. Txhawm rau kom tau txais cov ntaub ntawv tau txais los ntawm toluene / chloroform tov system kom ze rau qhov pom zoo polar tov system ntawm dej / formamide, peb siv ob lub polar kua tshuab los kuaj cellulose tib lub sijhawm, thiab tom qab ntawd tau txais qhov sib txuas sib txuas lossis kev cog lus coefficients. ua ntej thov Cov ntaub ntawv tau txais los ntawm impregnating cellulose ether nrog toluene / chloroform yog ze rau cov lus xaus tau txais rau cov dej / formamide system. Txij li cov cellulose ethers tau muab los ntawm cellulose thiab muaj cov qauv zoo sib xws ntawm ob, qhov kev kwv yees no yuav siv tau.

1.3.4 Kev suav tag nrho lub zog tsis muaj zog

2. Cov txiaj ntsig thiab kev sib tham

2.1 Cellulose tus qauv

Txij li thaum peb cov txiaj ntsig kev ntsuas ntawm cov qauv ntsuas cellulose pom tau tias cov ntaub ntawv no tau pom zoo nrog cov uas tau tshaj tawm hauv cov ntaub ntawv, nws tsim nyog ntseeg tias qhov kev sim ntsuas ntawm cellulose ethers yuav tsum tau txiav txim siab.

2.2 Cov txiaj ntsig kuaj thiab sib tham ntawm cellulose ether

Thaum lub sij hawm kev sim ntawm cellulose ether, nws yog ib qho nyuaj heev los sau cov immersion deb thiab lub sij hawm vim qhov siab immersion tsawg heev ntawm cov dej thiab formamide. Yog li, daim ntawv no xaiv cov toluene / chloroform tov system ua lwm txoj kev daws teeb meem, thiab kwv yees Lewis acidity ntawm cellulose ether raws li cov txiaj ntsig ntawm cov dej / formamide thiab toluene / chloroform ntawm cellulose thiab kev sib piv ntawm ob txoj kev daws teeb meem. thiab alkaline zog.

Noj cellulose raws li tus qauv qauv, ib tug series ntawm acid-base yam ntxwv ntawm cellulose ethers yog muab. Txij li thaum cov txiaj ntsig ntawm impregnating cellulose ether nrog toluene / chloroform raug kuaj ncaj qha, nws ntseeg tau.

Qhov no txhais tau hais tias hom thiab qhov hnyav molecular ntawm cov khoom hloov pauv cuam tshuam rau cov kua qaub-puag khoom ntawm cellulose ether, thiab kev sib raug zoo ntawm ob lub substituents, hydroxypropyl thiab hydroxypropylmethyl, ntawm cov kua qaub-puag khoom ntawm cellulose ether thiab molecular hnyav tag nrho opposite. Tab sis nws kuj tuaj yeem cuam tshuam nrog qhov tseeb tias MPs yog cov neeg hloov pauv.

Txij li cov hloov pauv ntawm MO43 thiab K8913 yog qhov sib txawv thiab muaj qhov hnyav molecular, piv txwv li, qhov hloov pauv ntawm qhov qub yog hydroxymethyl thiab qhov hloov ntawm qhov tom kawg yog hydroxypropyl, tab sis qhov hnyav molecular ntawm ob qho tib si yog 100,000, yog li nws kuj txhais tau hais tias qhov hloov pauv ntawm qhov tom kawg yog hydroxypropyl. Raws li qhov tshwm sim, qhov chaw ntawm S + thiab S- ntawm hydroxymethyl pawg yuav tsawg dua li pawg hydroxypropyl. Tab sis qhov degree ntawm kev hloov pauv kuj tseem ua tau, vim tias qhov kev hloov pauv ntawm K8913 yog li 3.00, thaum lub MO43 tsuas yog 1.90.

Txij li thaum qib ntawm kev hloov pauv thiab hloov pauv ntawm K8913 thiab K9113 yog tib yam tab sis tsuas yog qhov hnyav molecular txawv, qhov kev sib piv ntawm ob qhia tau hais tias S + ntawm hydroxypropyl cellulose txo qis nrog qhov nce ntawm molecular hnyav, tab sis S- nce ntawm qhov tsis sib xws. .

Los ntawm cov ntsiab lus ntawm qhov kev ntsuam xyuas ntawm lub zog saum npoo ntawm tag nrho cov cellulose ethers thiab lawv cov khoom, nws tuaj yeem pom tias nws yog cellulose lossis cellulose ether, lub ntsiab ntawm lawv lub zog saum npoo yog Lifshitz-van der Waals force, suav nrog. txog 98% ~ 99%. Tsis tas li ntawd, Lifshitz-van der Waals rog ntawm cov nonionic cellulose ethers (tshwj tsis yog MO43) kuj feem ntau loj dua cov cellulose, uas qhia tau hais tias cov txheej txheem etherification ntawm cellulose kuj yog ib tug txheej txheem ntawm nce Lifshitz-van der Waals rog. Thiab cov kev nce no ua rau lub zog saum npoo ntawm cellulose ether ua ntau dua li ntawm cellulose. Qhov tshwm sim no nthuav dav heev vim tias cov cellulose ethers feem ntau yog siv los tsim cov surfactants. Tab sis cov ntaub ntawv tseem ceeb, tsis yog vim hais tias cov ntaub ntawv hais txog tus qauv siv tus qauv sim hauv qhov kev sim no tsis tshua muaj txiaj ntsig nrog tus nqi tshaj tawm hauv cov ntaub ntawv, cov ntaub ntawv hais txog tus qauv siv tus qauv yog qhov zoo sib xws nrog tus nqi tshaj tawm hauv cov ntaub ntawv, rau Piv txwv li: tag nrho cov cellulose Lub SAB ntawm ethers yog me dua li ntawm cellulose, thiab qhov no yog vim lawv loj heev Lewis puag. Nyob rau hauv lub premise ntawm tib lub substituent thiab degree ntawm kev hloov, lub nto dawb zog ntawm hydroxypropyl cellulose yog proportional rau lub molecular hnyav; thaum lub zog tsis muaj zog ntawm hydroxypropyl methylcellulose yog proportional rau qhov kev hloov pauv thiab inversely proportional rau qhov hnyav molecular.

Tsis tas li ntawd, vim hais tias cellulose ethers muaj SLW loj dua cellulose, tab sis peb twb paub lawm hais tias lawv dispersibility yog zoo dua cellulose, yog li nws yuav tsum tau preminarily txiav txim siab tias lub ntsiab ntawm SLW constituting nonionic cellulose ethers yuav tsum yog lub London quab yuam.

3. Cov lus xaus

Cov kev tshawb fawb tau pom tias hom kev hloov pauv, qib ntawm kev hloov pauv thiab qhov hnyav molecular muaj qhov cuam tshuam zoo rau lub zog saum npoo thiab muaj pes tsawg leeg ntawm non-ionic cellulose ether. Thiab cov nyhuv no zoo li muaj cov hauv qab no tsis tu ncua:

(1) S + ntawm non-ionic cellulose ether yog me dua S-.

(2) Lub zog saum npoo ntawm nonionic cellulose ether yog dominated los ntawm Lifshitz-van der Waals quab yuam.

(3) Molecular hnyav thiab cov khoom hloov pauv muaj qhov cuam tshuam rau lub zog saum npoo ntawm cov tsis-ionic cellulose ethers, tab sis nws tsuas yog nyob ntawm hom hloov pauv.

(4) Raws li qhov kev xav tau ntawm tib qhov hloov pauv thiab qib ntawm kev hloov pauv, lub zog tsis muaj zog ntawm hydroxypropyl cellulose yog proportional rau qhov hnyav molecular; thaum lub zog tsis muaj zog ntawm hydroxypropyl methylcellulose yog proportional rau qhov kev hloov pauv thiab inversely proportional rau qhov hnyav molecular.

(5) Cov txheej txheem etherification ntawm cellulose yog txheej txheem uas Lifshitz-van der Waals quab yuam nce, thiab nws kuj yog cov txheej txheem uas Lewis acidity txo thiab Lewis alkalinity nce.