Cellulose Ether ntawm Epoxy Resin

Cov paj rwb thiab sawdust pov tseg yog siv los ua raw khoom, thiab yog hydrolyzed rau hauv alkalicellulose ethernyob rau hauv qhov kev txiav txim ntawm 18% alkali thiab ib tug series ntawm additives. Tom qab ntawd siv epoxy resin rau grafting, molar ratio ntawm epoxy resin thiab alkali fiber yog 0.5: 1.0, cov tshuaj tiv thaiv kub yog 100°C, lub sij hawm tshuaj tiv thaiv yog 5.0h, cov tshuaj catalyst yog 1%, thiab etherification grafting tus nqi yog 32%. Cov tau epoxy cellulose ether yog sib xyaw nrog 0.6mol Cel-Ep thiab 0.4mol CAB los ua ke cov khoom txheej tshiab nrog kev ua haujlwm zoo. Cov qauv khoom tau lees paub nrog IR.

Cov lus tseem ceeb:cellulose ether; synthesis; CAB; txheej txheej

Cellulose ether yog ib tug natural polymer, uas yog tsim los ntawm condensation ntawmβ- qabzib. Cellulose muaj qib siab ntawm polymerization, qib zoo ntawm kev taw qhia, thiab kev ruaj ntseg tshuaj zoo. Nws tuaj yeem tau txais los ntawm kev kho cov cellulose (esterification lossis etherification). A series ntawm cellulose derivatives, cov khoom no tau lug siv nyob rau hauv plastics, biodegradable noj su thawv, high-end automotive txheej, nws pib qhov chaw, luam ntawv inks, adhesives, thiab lwm yam. Tam sim no, tshiab hloov cellulose ntau yam yog tas li tshwm sim, thiab daim ntawv thov teb. txuas ntxiv nthuav dav, maj mam tsim cov kev lag luam fiber ntau. Lub ntsiab lus no yog siv cov sawdust lossis cov paj rwb pov tseg kom hydrolyzed rau hauv luv fibers los ntawm lye, thiab tom qab ntawd chemically grafted thiab hloov los ua ib hom tshiab txheej uas tsis tau qhia nyob rau hauv daim ntawv.

1. Kev sim

1.1 Reagents thiab ntsuas

Cov paj rwb pov tseg (ntxuav thiab qhuav), NaOH, 1,4-butanediol, methanol, thiourea, urea, epoxy resin, acetic anhydride, butyric acid, trichloroethane, formic acid, glyoxal, toluene, CAB, thiab lwm yam (Purity yog CP qib) . Magna-IR 550 infrared spectrometer tsim los ntawm Nicolet Tuam Txhab Tebchaws Meskas tau siv los npaj cov qauv los ntawm cov kuab tshuaj tetrahydrofuran txheej. Tu-4 viscometer, FVXD3-1 hom qhov kub thiab txias nws tus kheej-tswj hluav taws xob nplawm cov tshuaj tiv thaiv kettle, tsim los ntawm Weihai Xiangwei Chemical Machinery Factory; rotational viscometer NDJ-7, Z-10MP5 hom, tsim los ntawm Shanghai Tianping Instrument Factory; Qhov hnyav molecular yog ntsuas los ntawm Ubbelohde viscosity; Kev npaj thiab kev ntsuam xyuas cov xim xim yuav tsum tau ua raws li lub teb chaws tus qauv GB-79.

1.2 Reaction txoj cai

1.3 Synthesis

Synthesis ntawm epoxy cellulose: Ntxiv 100g ntawm tws paj rwb fiber mus rau qhov kub thiab txias nws tus kheej-tswj hluav taws xob stirring reactor, ntxiv ib qho oxidant thiab react rau 10 feeb, ces ntxiv cawv thiab alkali ua ib tug lye nrog ib tug concentration ntawm 18%. Ntxiv accelerators A, B, thiab lwm yam rau impregnation. Ua rau ntawm qhov kub thiab txias hauv lub tshuab nqus tsev rau 12 teev, lim, qhuav thiab hnyav 50g ntawm alkalized cellulose, ntxiv cov kuab tshuaj sib xyaw ua cov slurry, ntxiv cov catalyst thiab epoxy resin nrog qhov hnyav molecular, kub txog 90 ~ 110.℃rau etherification cov tshuaj tiv thaiv 4.0 ~ 6.0h kom txog thaum cov reactants yog miscible. Ntxiv formic acid rau neutralize thiab tshem tawm tshaj alkali, cais cov aqueous tov thiab hnyav, ntxuav nrog 80℃dej kub kom tshem tawm sodium ntsev, thiab qhuav rau tom qab siv. Lub viscosity intrinsic tau ntsuas nrog Ubbelohde viscometer thiab viscosity-nruab nrab molecular hnyav tau xam raws li cov ntaub ntawv.

Acetate butyl cellulose yog npaj raws li cov ntaub ntawv txoj kev, hnyav 57.2g ntawm refined paj rwb, ntxiv 55g ntawm acetic anhydride, 79g ntawm butyric acid, 9.5g ntawm magnesium acetate, 5.1g ntawm sulfuric acid, siv butyl acetate raws li hnyav, thiab reacts ntawm ib qho kub kom txog thaum tsim nyog, neutralized los ntawm kev ntxiv sodium acetate, precipitated, lim, ntxuav, lim, thiab qhuav rau tom qab siv. Noj Cel-Ep, ntxiv cov nqi tsim nyog ntawm CAB thiab cov kuab tshuaj sib xyaw ua ke, ua kom sov thiab do rau 0.5h los tsim cov kua tuab tuab, thiab txheej txheej txheej txheej npaj thiab kev sim ua raws li GB-79 txoj kev.

Kev txiav txim siab ntawm qib esterification ntawm cellulose acetate: thawj zaug yaj cellulose acetate nyob rau hauv dimethyl sulfoxide, ntxiv ib metered alkali tov rau tshav kub thiab hydrolyze, thiab titrate hydrolyzed tov nrog NaOH txheem tov los xam tag nrho cov alkali. Kev txiav txim siab ntawm cov ntsiab lus dej: Muab cov qauv tso rau hauv qhov cub ntawm 100 ~ 105°C kom qhuav rau 0.2h, hnyav thiab xam cov dej nqus dej tom qab txias. Kev txiav txim siab ntawm kev nqus alkali: ntsuas qhov ntsuas kom muaj nuj nqis, yaj hauv dej kub, ntxiv methyl violet ntsuas, thiab tom qab ntawd titrate nrog 0.05mol / L H2SO4. Kev txiav txim siab ntawm kev nthuav dav: Nyhav 50g qauv, tsoo nws thiab muab tso rau hauv ib lub raj kawm tiav, nyeem lub ntim tom qab hluav taws xob vibration, thiab muab piv nrog lub ntim ntawm unalkalined cellulose hmoov los xam cov expansion degree.

2. Cov txiaj ntsig thiab kev sib tham

2.1 Kev sib raug zoo ntawm alkali concentration thiab cellulose o degree

Cov tshuaj tiv thaiv ntawm cellulose nrog rau qee qhov concentration ntawm NaOH cov tshuaj tuaj yeem rhuav tshem cov cellulose tsis tu ncua thiab ua kom muaj zog thiab ua kom cov cellulose o. Thiab ntau yam degradation tshwm sim hauv lye, txo cov degree ntawm polymerization. Cov kev sim qhia tau hais tias qhov degree ntawm o ntawm cellulose thiab tus nqi ntawm alkali khi los yog adsorption nce nrog cov concentration ntawm alkali. Qhov degree ntawm hydrolysis nce nrog qhov nce ntawm qhov kub thiab txias. Thaum cov alkali concentration nce mus txog 20%, qhov degree ntawm hydrolysis yog 6.8% ntawm t = 100°C; Qib ntawm hydrolysis yog 14% ntawm t = 135°C. Tib lub sijhawm, qhov kev sim qhia tau hais tias thaum cov alkali ntau dua 30%, qhov degree ntawm hydrolysis ntawm cellulose saw scission yog txo qis. Thaum cov alkali concentration nce mus txog 18%, lub peev xwm adsorption thiab o ntawm cov dej yog qhov siab tshaj plaws, cov concentration tseem nce ntxiv, poob qis mus rau toj siab, thiab tom qab ntawd hloov tsis tu ncua. Nyob rau tib lub sijhawm, qhov kev hloov pauv no yog qhov nkag siab zoo rau qhov cuam tshuam ntawm qhov kub thiab txias. Nyob rau hauv tib lub alkali concentration, thaum kub tsawg (<20°C), qhov o ntawm cellulose yog loj, thiab cov adsorption tus nqi ntawm cov dej yog loj; ntawm qhov kub thiab txias, qhov o degree thiab dej adsorption tus nqi yog qhov tseem ceeb. txo.

Alkali fibers nrog cov dej sib txawv thiab cov ntsiab lus alkali tau txiav txim siab los ntawm X-ray diffraction tsom xam raws li cov ntaub ntawv. Hauv kev ua haujlwm tiag tiag, 18% ~ 20% lye yog siv los tswj qee qhov ntsuas kub kom nce qhov o ntawm cellulose. Cov kev sim qhia tau hais tias cov cellulose reacted los ntawm cua sov rau 6 ~ 12h yuav yaj nyob rau hauv polar solvents. Raws li qhov tseeb no, tus sau xav tias solubility ntawm cellulose plays lub luag hauj lwm txiav txim siab nyob rau hauv lub degree ntawm hydrogen bond kev puas tsuaj ntawm cellulose molecules nyob rau hauv lub crystalline segment, ua raws li los ntawm lub degree ntawm hydrogen bond puas tsuaj ntawm intramolecular qabzib pawg C3-C2. Qhov ntau dua qhov kev puas tsuaj ntawm hydrogen daim ntawv cog lus, qhov ntau dua qhov o ntawm alkali fiber ntau, thiab hydrogen daim ntawv cog lus raug rhuav tshem tag nrho, thiab qhov kawg hydrolyzate yog cov dej-soluble.

2.2 Cov nyhuv ntawm Accelerator

Ntxiv cov dej kub npau npau thaum lub sij hawm cellulose alkalization tuaj yeem ua rau muaj qhov kub thiab txias, thiab ntxiv cov tshuaj tiv thaiv me me xws li qis cawv thiab thiourea (los yog urea) tuaj yeem txhawb kev nkag mus thiab o ntawm cellulose. Raws li cov concentration ntawm cawv nce, alkali nqus ntawm cellulose nce, thiab muaj ib qho kev hloov tam sim ntawd thaum lub concentration yog 20%, uas tej zaum yuav hais tias monofunctional cawv nkag mus rau hauv cellulose molecules los tsim hydrogen bonds nrog cellulose, tiv thaiv cellulose. molecules Lub hydrogen bonds ntawm chains thiab molecular chains nce qib ntawm kev tsis sib haum xeeb, ua rau kom qhov chaw saum npoo av, thiab nce cov alkali adsorption. Txawm li cas los xij, nyob rau hauv tib lub sijhawm, kev nqus alkali ntawm cov ntoo chips yog tsawg, thiab qhov nkhaus hloov pauv hauv lub xeev hloov pauv. Nws tuaj yeem cuam tshuam nrog cov ntsiab lus qis ntawm cellulose hauv cov ntoo chips, uas muaj cov lignin ntau, uas cuam tshuam kev nkag mus ntawm cawv, thiab muaj dej tsis kam thiab alkali tsis kam.

2.3 Etherification

Ntxiv 1% B catalyst, tswj qhov sib txawv ntawm cov tshuaj tiv thaiv kub, thiab ua tiav kev hloov kho etherification nrog epoxy resin thiab alkali fiber ntau. Cov tshuaj tiv thaiv etherification yog tsawg ntawm 80°C. Tus nqi grafting ntawm Cel tsuas yog 28%, thiab cov kev ua etherification yog ze li ob npaug ntawm 110°C. Xav txog cov tshuaj tiv thaiv xws li hnyav, cov tshuaj tiv thaiv kub yog 100°C, thiab lub sij hawm cov tshuaj tiv thaiv yog 2.5h, thiab grafting tus nqi ntawm Cel tuaj yeem ncav cuag 41%. Tsis tas li ntawd, nyob rau theem pib ntawm cov tshuaj tiv thaiv etherification (<1.0h), vim yog cov tshuaj tiv thaiv heterogeneous ntawm alkali cellulose thiab epoxy resin, grafting tus nqi yog tsawg. Nrog rau qhov nce ntawm Cel etherification degree, nws maj mam hloov mus rau hauv homogeneous cov tshuaj tiv thaiv, yog li cov tshuaj tiv thaiv kev ua haujlwm tau nce sharply, thiab grafting tus nqi nce.

2.4 Kev sib raug zoo ntawm Cel grafting tus nqi thiab solubility

Kev sim tau pom tias tom qab grafting epoxy resin nrog alkali cellulose, lub cev muaj zog xws li cov khoom viscosity, adhesion, dej tsis kam, thiab thermal stability tuaj yeem txhim kho tau zoo. Solubility test Cov khoom nrog Cel grafting tus nqi <40% tuaj yeem yaj hauv qis cawv-ester, alkyd resin, polyacrylic acid resin, acrylic pimaric acid thiab lwm yam resins. Cel-Ep resin muaj cov nyhuv solubilizing pom tseeb.

Ua ke nrog cov txheej txheem zaj duab xis, cov khoom sib xyaw nrog grafting tus nqi ntawm 32% ~ 42% feem ntau muaj kev sib raug zoo dua, thiab cov khoom sib xyaw nrog cov grafting tus nqi ntawm <30% muaj kev sib raug zoo tsis zoo thiab tsis tshua muaj gloss ntawm cov zaj duab xis txheej; qhov grafting tus nqi siab dua 42%, cov dej kub npau npau, dej cawv tsis kam, thiab polar organic hnyav tsis kam ntawm txheej zaj duab xis yog txo. Txhawm rau txhim kho cov khoom sib raug zoo thiab txheej txheej, tus sau tau ntxiv CAB raws li cov qauv hauv Table 1 kom ntxiv solubilize thiab hloov kho los txhawb kev sib koom ua ke ntawm Cel-Ep thiab CAB. Qhov sib tov tsim ib qho approximate homogeneous system. Qhov sib xyaw ua ke ntawm qhov sib txawv ntawm qhov sib xyaw yog nyias nyias thiab sim ua nyob rau hauv lub xeev ntawm nano-hlwb.

2.5 Kev sib raug zoo ntawm Cel—Ep/CAB blending ratio thiab lub cev muaj zog

Siv Cel-Ep los ua ke nrog CAB, cov txheej txheem kuaj pom tau hais tias cellulose acetate tuaj yeem txhim kho cov txheej txheem ntawm cov khoom siv, tshwj xeeb tshaj yog kom qhuav ceev. Cov khoom xyaw ntshiab ntawm Cel-Ep yog qhov nyuaj kom qhuav ntawm chav tsev kub. Tom qab ntxiv CAB, ob cov ntaub ntawv muaj qhov pom tseeb ua tau zoo ntxiv.

2.6 FTIR spectrum kuaj pom

3. Cov lus xaus

(1) Paj rwb cellulose tuaj yeem o ntawm 80°C nrog> 18% concentrated alkali thiab cov khoom siv ntxiv, ua kom cov tshuaj tiv thaiv kub, ua kom ntev lub sij hawm cov tshuaj tiv thaiv, nce qib ntawm o thiab degradation kom txog thaum nws yog hydrolyzed tag.

(2) Etherification cov tshuaj tiv thaiv, Cel-Ep molar pub piv yog 2, cov tshuaj tiv thaiv kub yog 100°C, lub sij hawm yog 5h, lub catalyst npaum li cas yog 1%, thiab etherification grafting tus nqi tuaj yeem ncav cuag 32% ~ 42%.

(3) Kev hloov kho sib xyaw, thaum lub molar piv ntawm Cel-Ep: CAB = 3: 2, kev ua haujlwm ntawm cov khoom sib txuas yog qhov zoo, tab sis cov Cel-Ep ntshiab tsis tuaj yeem siv los ua cov txheej, tsuas yog ua cov nplaum.