Focus on Cellulose ethers

Kusarudza nzira yehydroxypropyl methylcellulose

Nzira yezita: hypromellose - kutsunga kwehydroxypropoxy - kutsunga kwehydroxypropoxy

Chiyero chekushandisa: Iyi nzira inoshandisa iyo hydroxypropoxy yekumisikidza nzira kuona zvirimo mu hydroxypropoxy mu hypromellose.

Iyi nzira inoshandiswa kune hypromellose.

Nheyo yeiyo nzira: Verenga zviri mukati meiyo hydroxypropoxy muchigadzirwa chekuyedza zvinoenderana neiyo hydroxypropoxy nzira yekumisikidza.

Reagent:

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

2. Sodium hydroxide titration solution (0.02mol/L)

3. Phenolphthalein chiratidzo chemhinduro

4. Sodium bicarbonate

5. Dilute sulfuric acid

6. Potassium iodide

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

8. Starch chiratidzo mhinduro

midziyo:

Kugadzirira kwemuenzaniso: 1. Sodium hydroxide titration solution (0.02mol/L)

Kugadzirira: Tora 5.6mL ye clear saturated sodium hydroxide solution, wedzera ichangobva kufashaidzwa mvura inotonhora kuti iite 1000mL.

Calibration: Tora inenge 6g ye potassium hydrogen phthalate yakaomeswa pa 105 ° C kuti irambe ichirema, zviyere zvakarurama, wedzera 50mL yemvura inotonhora ichangobva kubikwa, zunza kuti inyunguduke zvakanyanya sezvinobvira; wedzera madonhwe maviri ephenolphthalein chiratidzo chemhinduro, shandisa iyi Liquid titration, kana ichisvika kumagumo, iyo potassium hydrogen phthalate inofanira kunyungudutswa zvachose, uye titrated kusvikira mhinduro yava pink. Yese 1mL ye sodium hydroxide titration solution (1mol/L) yakaenzana ne 20.42mg ye potassium hydrogen phthalate. Verenga huwandu hwemhinduro iyi zvichienderana nekushandiswa kwemhinduro iyi uye huwandu hwe potassium hydrogen phthalate yakatorwa. Kuwedzeredza kashanu kuti ugadzire iyo 0.02mol / L.

Kuchengetedza: Isa mu polyethylene bhodhoro repurasitiki uye uchengetedze rakavharwa; pane maburi maviri mupulagi, uye 1 girazi chubhu inopinzwa mugomba rega rega, 1 chubhu inobatanidzwa nesoda lime chubhu, uye 1 chubhu inoshandiswa kusveta kunze mvura.

2. Phenolphthalein chiratidzo chemhinduro

Tora 1g ye phenolphthalein, wedzera 100mL ye ethanol kuti inyunguduke.

3. Sodium thiosulfate titration solution (0.02mol/L)

Kugadzirira: Tora 26g yesodium thiosulfate uye 0.20g yeanhydrous sodium carbonate, wedzera huwandu hwakakodzera hwemvura inotonhora ichangobva kufashaidzwa kuti inyunguduke kuita 1000mL, zunza zvakanaka, uye sefa mushure mekumira kwemwedzi mumwe.

Calibration: tora inenge 0.15g ye potassium dichromate yakaomeswa pa 120 ° C ine uremu hunogara huripo, huremu hwakakwana, uise mubhodhoro reiodine, wedzera 50mL yemvura kuti inyunguduke, wedzera 2.0g ye potassium iodide, zunza zvinyoronyoro kuti inyunguduke, wedzera. 40mL ye dilute sulfuric acid, Zunza zvakanaka uye simbisa zvakasimba; mushure memaminitsi gumi munzvimbo ine rima, wedzera 250mL yemvura kuti inyunguduke, uye kana mhinduro yacho yaiswa pedyo nekunoperera, wedzera 3mL ye starch indicator solution, ramba uchiita titration kusvika ruvara rwebhuruu rwanyangarika uye rukave girinhi inopenya, uye mhedzisiro yetitration. rinoshandiswa sechisina chinhu Chiyedzo kugadzirisa. Yese 1mL yesodium thiosulfate (0.1mol/L) yakaenzana ne4.903g ye potassium dichromate. Verenga huwandu hwemhinduro maererano nekudyiwa kwemushonga uye huwandu hwe potassium dichromate yakatorwa. Kuwedzeredza kashanu kuti ugadzire iyo 0.02mol / L.

Kana tembiricha yemukamuri iri pamusoro pe25°C, tembiricha yemushonga wemhinduro uye mvura yedilution inofanira kutonhodzwa kusvika pa20°C.

4. Starch chiratidzo mhinduro

Tora 0.5g ye starch yakanyunguduka, woisa 5mL yemvura wovhenganisa zvakanaka, wozodira zvishoma nezvishoma mu 100mL yemvura iri kufashaira, simbisa sezvaunowedzera, ramba uchifashaira kwemaminetsi maviri, rega kutonhorera, durura mashura, uye unowana. Iyi mhinduro inofanira kugadzirirwa kutsva isati yashandiswa.

Matanho ekushanda: Tora 0.1g yechigadzirwa ichi, chiyera nemazvo, chiise mubhodhoro re distillation D, wedzera 10mL ye30% (g/g) cadmium trichloride solution. Zadza chubhu inogadzira chiutsi B nemvura kujoinhi, uye batanidza iyo distillation unit. Nyura zvese B uye D mubhavhu rekugezesa mafuta (inogona kunge iri glycerin), ita kuti mwero wemvura yekugeza mafuta uenderane nehuwandu hwemvura yecadmium trichloride solution mubhodhoro D, vhura mvura inotonhorera, uye kana zvichidikanwa, rega. iyo nitrogen stream inoyerera ichipinda uye inodzora kuyerera kwayo kusvika pa 1 bubble pasekondi. Mukati memaminitsi makumi matatu, simudza tembiricha yekugezera mafuta kusvika 155ºC, uye chengetedza tembiricha iyi kusvika 50 mL ye distillate yaunganidzwa, bvisa condenser chubhu kubva pachikamu chechikamu, sukurudza nemvura, geza uye usanganise mumvura yakaunganidzwa, wedzera 3. madonhwe ephenolphthalein indicator solution, uye shandisa Titrate kusvika pH value iri 6.9-7.1 (yakayerwa ne acidity meter), rekodha vhoriyamu yakadyiwa V1 (mL), wobva wawedzera 0.5g ye sodium bicarbonate uye 10mL ye dilute sulfuric acid, rega zvidaro. mira kusvika pasisina carbon dioxide yagadzirwa, wedzera 1.0g ye potassium iodide, Isa chisimbiso zvakasimba, zunza zvakanaka, isa munzvimbo ine rima kwemaminitsi mashanu, wedzera 1mL ye starch indicator solution, titrate kusvika kumagumo ne sodium thiosulfate titration. mhinduro (0.02mol/L), uye rekodha vhoriyamu yakadyiwa V2 (mL). Mune imwe bvunzo isina chinhu, rekodha mavhoriyamu Va uye Vb (mL) yeyakadyiwa sodium hydroxide titration solution (0.02mol/L) uye sodium thiosulfate titration solution (0.02mol/L) zvichiteerana. Verenga iyo hydroxypropoxyl yemukati.


Nguva yekutumira: Kubvumbi-14-2023
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