Focus on Cellulose ethers

Indlela yokunquma ye-hydroxypropyl methylcellulose

Igama lendlela: i-hypromellose - ukunqunywa kwe-hydroxypropoxy - ukunqunywa kwe-hydroxypropoxy

Ububanzi bokusebenza: Le ndlela isebenzisa indlela yokunquma i-hydroxypropoxy ukuze inqume okuqukethwe kwe-hydroxypropoxy ku-hypromellose.

Le ndlela isetshenziswa ku-hypromellose.

Isimiso sendlela: Bala okuqukethwe kwe-hydroxypropoxy emkhiqizweni wokuhlola ngokuya ngendlela yokunquma i-hydroxypropoxy.

I-Reagent:

1. 30% (g/g) isixazululo se-chromium trioxide

2. Isixazululo se-sodium hydroxide titration (0.02mol/L)

3. Isixazululo senkomba ye-Phenolphthalein

4. I-sodium bicarbonate

5. Nciphisa i-sulfuric acid

6. Iodide ye-Potassium

7. Isixazululo se-sodium thiosulfate titration (0.02mol/L)

8. Isixazululo senkomba yesitashi

okokusebenza:

Ukulungiswa kwesampula: 1. Isixazululo se-sodium hydroxide titration (0.02mol/L)

Ukulungiselela: Thatha u-5.6mL wesisombululo se-sodium hydroxide ecacile, engeza amanzi abandayo asanda kubiliswa ukuze abe ngu-1000mL.

Ukulinganisa: Thatha cishe u-6g we-potassium hydrogen phthalate evamile omisiwe ku-105°C ukuze ube nesisindo esingashintshi, yikale ngokunembile, engeza u-50mL wamanzi abandayo asanda kubiliswa, unyakazise ukuze ancibilike ngangokunokwenzeka; engeza amaconsi angu-2 esisombululo senkomba ye-phenolphthalein, sebenzisa le-titration ye-Liquid, lapho usondela endaweni yokugcina, i-potassium hydrogen phthalate kufanele ichithwe ngokuphelele, futhi ifakwe kuze kube yilapho isisombululo siba pink. Njalo nge-1mL yesisombululo se-sodium hydroxide titration (1mol/L) ilingana no-20.42mg we-potassium hydrogen phthalate. Bala ukugxila kwalesi sixazululo ngokusekelwe ekusetshenzisweni kwalesi sixazululo kanye nenani le-potassium hydrogen phthalate elithathiwe. Kakhulu hlanza izikhathi ezi-5 ukwenza ukugxila kube ngu-0.02mol/L.

Isitoreji: Yifake ebhodleleni lepulasitiki le-polyethylene futhi uligcine livaliwe; kunezimbobo ezi-2 kupulaki, kanye neshubhu lengilazi elingu-1 lifakwa emgodini ngamunye, ishubhu eli-1 lixhunywe neshubhu le-soda lime, bese kusetshenziswa ishubhu elilodwa ukumunca uketshezi.

2. Isixazululo senkomba ye-Phenolphthalein

Thatha i-1g ye-phenolphthalein, engeza i-100mL ye-ethanol ukuze incibilike.

3. Isixazululo se-sodium thiosulfate titration (0.02mol/L)

Ukulungiselela: Thatha u-26g we-sodium thiosulfate kanye no-0.20g we-anhydrous sodium carbonate, engeza inani elifanele lamanzi abandayo asanda kubiliswa ukuze uncibilike abe ngu-1000mL, unyakazise kahle, bese uhlunga ngemva kokuma inyanga eyodwa.

Ukulinganisa: thatha cishe u-0.15g we-potassium dichromate evamile omisiwe ku-120 ° C enesisindo esingaguquki, uyikale ngokunembile, uyibeke ebhodleleni le-iodine, engeza u-50mL wamanzi ukuze uncibilike, engeza u-2.0g we-potassium iodide, unyakazise kancane ukuze uncibilike, engeza. 40mL we-dilute sulfuric acid, Shake kahle futhi uvale ngokuqinile; emva kwemizuzu eyi-10 endaweni emnyama, engeza u-250mL wamanzi ukuze uhlanjululwe, futhi lapho isixazululo sincishiselwa eduze nendawo yokugcina, engeza u-3mL wesisombululo senkomba yesitashi, qhubeka nokubhala kuze kube yilapho umbala oluhlaza unyamalala futhi uba luhlaza ngokugqamile, kanye nomphumela wokulinganisa. isetshenziswa njengokulungiswa kwesivivinyo esingenalutho. Njalo nge-1mL ye-sodium thiosulfate (0.1mol/L) ilingana no-4.903g we-potassium dichromate. Bala ukugxila kwesixazululo ngokuya ngokusetshenziswa kwesixazululo kanye nenani le-potassium dichromate elithathiwe. Kakhulu hlanza izikhathi ezi-5 ukwenza ukugxila kube ngu-0.02mol/L.

Uma izinga lokushisa lekamelo lingaphezu kuka-25°C, izinga lokushisa lesixazululo sokuphendula kanye namanzi okuhlanjululwa kufanele apholise libe ngu-20°C.

4. Isixazululo senkomba yesitashi

Thatha u-0.5g wesitashi esincibilikayo, faka u-5mL wamanzi futhi ugovuze kahle, bese uthela kancane kancane ku-100mL wamanzi abilayo, ugovuze njengoba ufaka, qhubeka ubilise imizuzu engu-2, uvumele kuphole, uthele i-supernatant, futhi uyayithola. Lesi sixazululo kufanele silungiswe kabusha ngaphambi kokusetshenziswa.

Izinyathelo zokusebenza: Thatha u-0.1g walo mkhiqizo, ukale ngokunembile, uwubeke ebhodleleni lokuhluza i-distillation D, engeza u-10mL ka-30% (g/g) wesisombululo se-cadmium trichloride. Gcwalisa ishubhu B ekhiqiza isitimu ngamanzi ejoyintini, bese uxhuma iyunithi yokugaya. Gxilisa kokubili u-B no-D endaweni yokugeza kawoyela (kungaba i-glycerin), yenza izinga loketshezi lokugeza likawoyela lihambisane nezinga eliwuketshezi lesixazululo se-cadmium trichloride ebhodleleni D, uvule amanzi okupholisa, futhi uma kunesidingo, vumela. ukugeleza kwe-nitrogen kugeleza futhi kulawule izinga lokugeleza kwalo libe ibhamuza elingu-1 ngomzuzwana. Phakathi nemizuzu engama-30, phakamisa izinga lokushisa lokugeza lamafutha libe ku-155ºC, futhi ugcine lokhu kushisa kuze kuqoqwe u-50 mL we-distillate, khipha ishubhu le-condenser kukholomu yokuhlukanisa, hlambulula ngamanzi, geza futhi uhlanganise noketshezi oluqoqiwe, engeza 3. amaconsi esixazululo senkomba ye-phenolphthalein, bese usebenzisa i-Titrate kuze kube inani le-pH libe ngu-6.9-7.1 (ikalwa ngemitha ye-acidity), rekhoda umthamo osetshenzisiwe ongu-V1 (mL), bese wengeza u-0.5g we-sodium bicarbonate no-10mL we-dilute sulfuric acid, uvumele yima kuze kuphele i-carbon dioxide, engeza u-1.0g we-potassium iodide, Yivale ngokuqinile, uyinyakazise kahle, uyibeke endaweni emnyama imizuzu engu-5, engeza i-1mL yesisombululo se-starch indicator, i-titrate ifike ekugcineni nge-sodium thiosulfate titration. isisombululo (0.02mol/L), bese urekhoda umthamo osetshenzisiwe we-V2 (mL). Kwesinye isivivinyo esingenalutho, rekhoda imiqulu ye-Va ne-Vb (mL) yesisombululo se-sodium hydroxide titration (0.02mol/L) ne-sodium thiosulfate titration solution (0.02mol/L) ngokulandelana. Bala okuqukethwe kwe-hydroxypropoxyl.


Isikhathi sokuthumela: Apr-14-2023
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