Cov yam ntxwv ntawm carboxymethyl cellulose yog dab tsi?

Cov yam ntxwv ntawm carboxymethyl cellulose yog dab tsi?

Lus teb:Carboxymethyl cellulosekuj muaj cov khoom sib txawv vim nws cov degree sib txawv ntawm kev hloov pauv. Lub degree ntawm kev hloov pauv, tseem hu ua degree ntawm etherification, txhais tau tias tus lej nruab nrab ntawm H hauv peb pawg OH hydroxyl hloov los ntawm CH2COONa. Thaum peb pawg hydroxyl ntawm lub nplhaib cellulose-based muaj 0.4 H hauv pawg hydroxyl hloov los ntawm carboxymethyl, nws tuaj yeem yaj hauv dej. Lub sijhawm no, nws hu ua 0.4 substitution degree lossis medium substitution degree (substitution degree 0.4-1.2).

Cov khoom ntawm carboxymethyl cellulose:

(1) Nws yog hmoov dawb (lossis cov noob loj, fibrous), tsis muaj saj, tsis muaj teeb meem, yooj yim yaj hauv dej, thiab tsim cov duab nplaum pob tshab, thiab cov tshuaj yog nruab nrab lossis me ntsis alkaline. Nws muaj kev sib kis zoo thiab lub zog khi.

(2) Nws cov kua dej siv tau ua cov emulsifier ntawm hom roj / dej thiab hom dej / roj. Nws kuj muaj peev xwm emulsifying rau roj thiab quav ciab, thiab yog ib qho emulsifier muaj zog.

(3) Thaum cov tshuaj ntsib cov ntsev hlau hnyav xws li lead acetate, ferric chloride, silver nitrate, stannous chloride, thiab potassium dichromate, nag los yuav tshwm sim. Txawm li cas los xij, tsuas yog lead acetate xwb, nws tseem tuaj yeem yaj dua hauv cov kua sodium hydroxide, thiab cov nag los xws li barium, hlau thiab txhuas yooj yim yaj hauv 1% ammonium hydroxide kua.

(4) Thaum cov tshuaj ntsib cov organic acid thiab cov inorganic acid kua, cov nag tuaj yeem tshwm sim. Raws li kev soj ntsuam, thaum tus nqi pH yog 2.5, qhov turbidity thiab nag tau pib. Yog li ntawd pH 2.5 tuaj yeem suav hais tias yog qhov tseem ceeb.

(5) Rau cov ntsev xws li calcium, magnesium thiab ntsev hauv rooj, yuav tsis muaj nag lossis daus tshwm sim, tab sis qhov viscosity yuav tsum txo qis, xws li ntxiv EDTA lossis phosphate thiab lwm yam tshuaj kom tiv thaiv nws.

(6) Kub muaj feem cuam tshuam loj rau qhov viscosity ntawm nws cov kua dej. Lub viscosity txo qis sib xws thaum kub nce, thiab vice versa. Qhov ruaj khov ntawm viscosity ntawm cov kua dej ntawm chav tsev kub tseem tsis hloov pauv, tab sis viscosity tuaj yeem maj mam txo qis thaum cua sov tshaj 80 ° C rau lub sijhawm ntev. Feem ntau, thaum kub tsis tshaj 110 ° C, txawm tias qhov kub tau khaws cia rau 3 teev, thiab tom qab ntawd txias rau 25 ° C, qhov viscosity tseem rov qab mus rau nws lub xeev qub; tab sis thaum kub raug cua sov rau 120 ° C rau 2 teev, txawm hais tias qhov kub rov qab los, qhov viscosity poob qis los ntawm 18.9%. .

(7) Tus nqi pH kuj tseem yuav muaj qee qhov cuam tshuam rau qhov viscosity ntawm nws cov kua dej. Feem ntau, thaum pH ntawm cov kua qis-viscosity deviates ntawm qhov nruab nrab, nws cov viscosity muaj qhov cuam tshuam me ntsis, thaum rau cov kua nruab nrab-viscosity, yog tias nws cov pH deviates ntawm qhov nruab nrab, qhov viscosity pib txo qis maj mam; yog tias pH ntawm cov kua siab-viscosity deviates ntawm qhov nruab nrab, nws cov viscosity yuav txo qis. Ib qho kev poob qis.

(8) Sib xws nrog lwm cov kua nplaum uas yaj tau hauv dej, cov tshuaj ua kom mos thiab cov resins. Piv txwv li, nws sib xws nrog cov kua nplaum tsiaj, cov roj hmab arabic, glycerin thiab cov hmoov txhuv nplej uas yaj tau. Nws kuj sib xws nrog cov iav dej, polyvinyl cawv, urea-formaldehyde resin, melamine-formaldehyde resin, thiab lwm yam, tab sis tsawg dua.

(9) Zaj duab xis ua los ntawm kev siv lub teeb ultraviolet rau 100 teev tseem tsis muaj kev hloov pauv lossis brittleness.

(10) Muaj peb qhov ntau thiab tsawg viscosity xaiv los ntawm raws li daim ntawv thov. Rau gypsum, siv viscosity nruab nrab (2% aqueous kua ntawm 300-600mPa · s), yog tias koj xaiv viscosity siab (1% kua ntawm 2000mPa · s lossis ntau dua), koj tuaj yeem siv nws hauv qhov ntau npaum li cas yuav tsum tau txo qis kom tsim nyog.

(11) Nws cov kua dej ua haujlwm ua tus neeg tiv thaiv hauv gypsum.

(12) Cov kab mob thiab cov kab mob me me tsis muaj qhov cuam tshuam rau nws cov hmoov, tab sis lawv muaj qhov cuam tshuam rau nws cov kua dej. Tom qab muaj kuab paug, qhov viscosity yuav poob thiab mildew yuav tshwm sim. Ntxiv cov tshuaj preservatives kom tsim nyog ua ntej tuaj yeem tswj nws cov viscosity thiab tiv thaiv mildew ntev. Cov tshuaj preservatives muaj yog: BIT (1.2-benzisothiazolin-3-ib), racebendazim, thiram, chlorothalonil, thiab lwm yam. Tus nqi ntxiv hauv cov kua dej yog 0.05% txog 0.1%.

Hydroxypropyl methylcellulose ua tau zoo npaum li cas ua tus neeg sawv cev khaws dej rau anhydrite binder?

Lus Teb: Hydroxypropyl methylcellulose yog ib yam khoom siv uas khaws dej tau zoo rau cov khoom siv gypsum cementitious. Thaum cov hydroxypropyl methylcellulose ntau ntxiv, cov dej ntawm cov khoom siv cemented gypsum yuav khaws tau sai sai. Thaum tsis muaj cov khoom siv khaws dej ntxiv, cov dej ntawm cov khoom siv cemented gypsum yuav khaws tau li ntawm 68%. Thaum cov dej ntawm cov khoom siv khaws dej yog 0.15%, cov dej ntawm cov khoom siv cemented gypsum yuav khaws tau txog 90.5%. Thiab cov dej uas yuav tsum tau khaws ntawm cov plaster hauv qab. Cov tshuaj ntawm cov khoom siv khaws dej ntau dua 0.2%, ua kom cov tshuaj ntau ntxiv, thiab cov dej ntawm cov khoom siv cementitious gypsum yuav khaws tau qeeb qeeb. Kev npaj cov khoom siv plastering anhydrite. Cov tshuaj hydroxypropyl methylcellulose uas tsim nyog yog 0.1% -0.15%.

Cov teebmeem sib txawv ntawm cov cellulose sib txawv ntawm plaster of paris yog dab tsi?

Lus Teb: Ob qho tib si carboxymethyl cellulose thiab methyl cellulose tuaj yeem siv ua cov neeg sawv cev khaws dej rau plaster of paris, tab sis cov nyhuv khaws dej ntawm carboxymethyl cellulose qis dua li ntawm methyl cellulose, thiab carboxymethyl cellulose muaj sodium ntsev, yog li nws tsim nyog rau Plaster of Paris muaj cov nyhuv qeeb thiab txo qhov zog ntawm plaster.Methyl celluloseyog ib qho admixture zoo tagnrho rau cov ntaub ntawv gypsum cementitious uas sib xyaw ua ke cov dej khaws cia, thickening, strengthening, thiab viscosifying, tsuas yog tias qee hom muaj qhov cuam tshuam retarding thaum cov koob tshuaj ntau dua li carboxymethyl cellulose. Vim li no, feem ntau cov ntaub ntawv gypsum composite gelling siv txoj kev sib xyaw carboxymethyl cellulose thiab methyl cellulose, uas tsis tsuas yog ua rau lawv cov yam ntxwv (xws li qhov cuam tshuam retarding ntawm carboxymethyl cellulose, qhov cuam tshuam reinforcing ntawm methyl cellulose), thiab ua rau lawv cov txiaj ntsig zoo sib xws (xws li lawv qhov kev khaws cia dej thiab thickening effect). Ua li no, ob qho tib si kev ua tau zoo ntawm cov ntaub ntawv gypsum cementitious thiab kev ua tau zoo ntawm cov ntaub ntawv gypsum cementitious tuaj yeem txhim kho, thaum tus nqi nce ntxiv khaws cia ntawm qhov qis tshaj plaws.