Dissolving method thiab kev txiav txim siab ntawm hydroxypropyl methylcellulose HPMC

kev sim

Txoj kev lub npe: hypromellose - kev txiav txim siab ntawm hydroxypropoxy pawg - kev txiav txim ntawm hydroxypropoxy pawg

Scope ntawm daim ntawv thov: Txoj kev no siv txoj kev txiav txim siab hydroxypropoxy los txiav txim cov ntsiab lus ntawm hydroxypropoxy hauv hypromellose. Txoj kev no siv tau rau hypromellose.

Txoj cai ntawm txoj kev:Xam covCov ntsiab lus ntawm hydroxypropoxy hauv cov khoom kuaj raws li txoj kev txiav txim siab hydroxypropoxy.

Reagent:

1. 30% (g / g) chromium trioxide tov

2. Hydroxide

3. Phenolphthalein qhia kev daws teeb meem

4. Sodium bicarbonate

5. Dilute sulfuric acid

6. Potassium iodide

7. Sodium thiosulfate titration tov (0.02mol/L)

8. Starch indicator solution

khoom siv:

Kev npaj ua piv txwv:

1. Sodium hydroxide titration tov (0.02mol/L)

Kev npaj: Noj 5.6mL ntawm ntshiab saturated sodium hydroxide tov, ntxiv freshly boiled dej txias kom nws 1000mL.

Calibration: Siv li 6g ntawm tus qauv poov tshuaj hydrogen phthalate qhuav ntawm 105 ° C kom qhov hnyav tas li, ntsuas nws kom raug, ntxiv 50mL ntawm cov dej txias boiled tshiab, co kom nws yaj kom ntau li ntau tau; Ntxiv 2 tee ntawm cov tshuaj phenolphthalein qhia, siv cov kua titration no, thaum mus txog qhov kawg taw tes, cov poov tshuaj hydrogen phthalate yuav tsum tau yaj tag, thiab titrated kom txog thaum cov tshuaj ua liab dawb. Txhua 1mL ntawm sodium hydroxide titration tov (1mol / L) yog sib npaug rau 20.42mg ntawm potassium hydrogen phthalate. Xam cov concentration ntawm cov tshuaj no raws li kev noj cov tshuaj no thiab tus nqi ntawm cov poov tshuaj hydrogen phthalate noj. Quantitatively dilute 5 zaug kom muaj qhov concentration 0.02mol / L.

Cia: Muab tso rau hauv lub raj mis yas polyethylene thiab khaws cia; muaj 2 qhov ntawm lub ntsaws, thiab 1 lub raj iav tau muab tso rau hauv txhua lub qhov, 1 lub raj txuas nrog lub raj dej qab ntsev, thiab 1 lub raj yog siv los nqus cov kua dej.

2. Phenolphthalein indicator solution Siv 1g ntawm phenolphthalein, ntxiv 100mL ntawm ethanol kom yaj

3. Sodium thiosulfate titration solution (0.02mol/L) Kev Npaj: Noj 26g ntawm sodium thiosulfate thiab 0.20g ntawm anhydrous sodium carbonate, ntxiv ib qho tsim nyog ntawm cov dej txias boiled tshiab kom yaj rau hauv 1000mL, co zoo, thiab tso rau 1 lub hlis lim. Calibration: noj li 0.15g ntawm tus qauv poov tshuaj dichromate qhuav ntawm 120 ° C nrog qhov hnyav tas li, hnyav nws, muab tso rau hauv ib lub raj mis iodine, ntxiv 50mL dej kom yaj, ntxiv 2.0g ntawm poov tshuaj iodide, co maj mam kom yaj, ntxiv 40mL ntawm dilute sulfuric acid, co zoo thiab kaw ntom nti. Tom qab 10 feeb nyob rau hauv ib qho chaw tsaus, ntxiv 250mL dej kom dilute, thiab thaum cov tshuaj yog titrated mus rau ze ntawm qhov kawg point, ntxiv 3mL ntawm starch indicator solution, txuas ntxiv titration kom txog rau thaum lub xiav xim ploj mus thiab yuav ci ntsuab, thiab titration tshwm sim yog siv raws li ib tug dawb paug mus sib kho. Txhua 1mL ntawm sodium thiosulfate (0.1mol / L) yog sib npaug rau 4.903g ntawm potassium dichromate. Xam cov concentration ntawm cov tshuaj raws li kev noj cov tshuaj thiab cov tshuaj potassium dichromate npaum li cas. Quantitatively dilute 5 zaug kom muaj qhov concentration 0.02mol / L. Yog tias chav tsev kub siab tshaj 25 ° C, qhov kub ntawm cov tshuaj tiv thaiv thiab cov dej dilution yuav tsum tau txias txog li 20 ° C.

4. Starch indicator solution Siv 0.5g ntawm soluble starch, ntxiv 5mL dej thiab do zoo, ces maj mam ncuav rau hauv 100mL ntawm boiling dej, do raws li nws yog ntxiv, ntxiv boil rau 2 feeb, cia txias, ncuav tawm lub supernatant, thiab nws yog npaj txhij.

Cov tshuaj no yuav tsum tau npaj tshiab ua ntej siv.

Cov kauj ruam ua haujlwm: Siv 0.1g ntawm cov khoom no, ntsuas kom raug, muab tso rau hauv lub raj mis distillation D, ntxiv 10mL ntawm 30% (g / g) cadmium trichloride tov. Sau lub tshuab tsim hluav taws xob B nrog dej rau qhov sib koom ua ke, thiab txuas lub tshuab distillation. Muab ob qho tib si B thiab D rau hauv cov roj da dej (nws tuaj yeem yog glycerin), ua kom cov kua theem ntawm cov roj da dej kom zoo raws li cov kua theem ntawm cadmium trichloride tov hauv lub raj mis D, tig rau cov dej txias, thiab yog tias tsim nyog, cia cov kwj nitrogen ntws mus rau hauv thiab tswj nws tus nqi ntws mus rau 1 npuas ib ob. Tsis pub dhau 30 feeb, nce qhov kub ntawm cov roj da dej mus rau 155ºC, thiab tswj qhov kub no kom txog thaum 50 mL ntawm cov distillate tau sau, tshem tawm cov condenser raj los ntawm cov fractionation kem, yaug nrog dej, ntxuav thiab sib xyaw rau hauv cov tshuaj sib sau, ntxiv 3 tee ntawm phenolphthalein tov, thiab titrate nrog acidity 7-1. ' meter '), sau cov ntim ntim V1 (mL), tom qab ntawd ntxiv 0.5g ntawm sodium bicarbonate thiab 10mL ntawm dilute sulfuric acid, cia nws sawv ntsug kom txog thaum tsis muaj carbon dioxide ntau, ntxiv 1.0g ntawm poov tshuaj iodide, thiab kaw nws, co zoo, qhov chaw tsaus rau 5 feeb, ntxiv 1mL ntawm cov hmoov txhuv nplej siab, sodium titration tov. (0.02mol / L) mus rau qhov kawg taw tes, sau cov ntim ntim V2 (mL). Hauv lwm qhov kev kuaj dawb, sau cov ntim Va thiab Vb (mL) ntawm cov tshuaj sodium hydroxide titration (0.02mol / L) thiab sodium thiosulfate titration tov (0.02mol / L) raws li.