Lebitso la mokhoa: hypromellose - boikemisetso ba hydroxypropoxy - boikemisetso ba hydroxypropoxy
Sebaka sa ts'ebeliso: Mokhoa ona o sebelisa mokhoa oa ho etsa qeto ea hydroxypropoxy ho fumana hore na hydroxypropoxy e teng ho hypromellose.
Mokhoa ona o sebetsa ho hypromellose.
Molao-motheo oa mokhoa: Bala litaba tsa hydroxypropoxy sehlahisoa sa tlhahlobo ho latela mokhoa oa ho etsa qeto ea hydroxypropoxy.
Reagent:
1. 30% (g/g) tharollo ea chromium trioxide
2. Tharollo ea sodium hydroxide titration (0.02mol/L)
3. Phenolphthalein indicator tharollo
4. Sodium bicarbonate
5. Hlakola sulfuric acid
6. Potassium iodide
7. Tharollo ea sodium thiosulfate titration (0.02mol/L)
8. Tharollo ea letšoao la starch
thepa:
Tokiso ea mohlala: 1. Sodium hydroxide titration solution (0.02mol/L)
Boitokisetso: Nka 5.6mL ea tharollo e hlakileng ea sodium hydroxide, eketsa metsi a batang a sa tsoa phehoa ho etsa 1000mL.
Tekanyetso: Nka hoo e ka bang 6g ea potassium hydrogen phthalate e tloaelehileng e omisitsoeng ho 105 ° C ho boima bo sa khaotseng, e lekanya ka nepo, eketsa 50mL ea metsi a batang a sa tsoa phehoa, sisinya ho etsa hore e qhibilihe ka hohle kamoo ho ka khonehang; eketsa marotholi a 2 a tharollo ea phenolphthalein indicator, sebelisa titration ena ea Liquid, ha e atamela ntlha ea ho qetela, potassium hydrogen phthalate e lokela ho qhibiliha ka ho feletseng, 'me e fokotsehe ho fihlela tharollo e fetoha pinki. 1mL e 'ngoe le e 'ngoe ea sodium hydroxide titration solution (1mol/L) e lekana le 20.42mg ea potassium hydrogen phthalate. Bala palo ea tharollo ena ho latela tšebeliso ea tharollo ena le palo ea potasiamo hydrogen phthalate e nkiloeng. Hlakola ka makhetlo a 5 ho etsa hore khatello e be 0.02mol/L.
Ho boloka: E kenye ka botlolong ea polasetiki ea polyethylene 'me u boloke e tiisitsoe; ho na le masoba a 2 polakang, 'me thapo e le 'ngoe ea khalase e kenngoa ka sekoting se seng le se seng, tube e le 1 e hoketsoe ka tube ea lime ea soda, 'me e le 1 e sebelisoa ho monya mokelikeli.
2. Phenolphthalein indicator tharollo
Nka 1g ea phenolphthalein, eketsa 100mL ea ethanol ho qhaqha.
3. Tharollo ea sodium thiosulfate titration (0.02mol/L)
Boitokisetso: Nka 26g ea sodium thiosulfate le 0.20g ea anhydrous sodium carbonate, eketsa palo e loketseng ea metsi a batang a qetang ho belisoa ho qhibiliha ka 1000mL, sisinya hantle, 'me u sefa ka mor'a ho ema khoeli e le 1.
Calibration: nka hoo e ka bang 0.15g ea dichromate e tloaelehileng ea potassium e omisitsoeng ka 120 ° C ka boima bo sa feleng, e lekanya ka nepo, e behe ka botlolo ea iodine, eketsa 50mL ea metsi ho qhibiliha, eketsa 2.0g ea iodide ea potasiamo, sisinya ka bonolo ho qhibiliha, eketsa 40mL ea dilute sulfuric acid, Shake hantle 'me u tiise ka thata; ka mor'a metsotso e 10 sebakeng se lefifi, eketsa 250mL ea metsi ho hlapolla, 'me ha tharollo e lekanyelitsoe ho fihlela qetellong, eketsa 3mL ea tharollo ea starch indicator, tsoela pele ho fetola ho fihlela 'mala o moputsoa o nyamela' me o fetoha o motala o khanyang, le phello ea titration. e sebelisoa e le tokiso ea teko e se nang letho. 1mL e 'ngoe le e 'ngoe ea sodium thiosulfate (0.1mol/L) e lekana le 4.903g ea potassium dichromate. Lekola bongata ba tharollo ho latela tšebeliso ea tharollo le palo ea potassium dichromate e nkiloeng. Hlakola ka makhetlo a 5 ho etsa hore khatello e be 0.02mol/L.
Haeba mocheso oa kamore o ka holimo ho 25 ° C, mocheso oa tharollo ea ho arabela le metsi a hlapollo o lokela ho pholile ho fihlela ho 20 ° C.
4. Tharollo ea letšoao la starch
Nka 0.5g ea starch e qhibilihang, eketsa 5mL ea metsi 'me u hlohlelletse hantle, ebe butle-butle tšela 100mL ea metsi a belang, hlohlelletsa ha u ntse u eketsa, tsoela pele ho pheha metsotso e 2, tlohela ho pholile, u tšollele supernatant,' me ue fumane. Tharollo ena e lokela ho lokisoa bocha pele e sebelisoa.
Mehato ea ts'ebetso: Nka 0.1g ea sehlahisoa sena, se lekanye ka nepo, se kenye ka botlolong ea distillation D, eketsa 10mL ea 30% (g/g) tharollo ea cadmium trichloride. Tlatsa tube e hlahisang mouoane B ka metsi lenonyeletsong, 'me u kopanye yuniti ea distillation. Kenya ka bobeli B le D ka bateng ea oli (e ka ba glycerin), etsa hore boemo ba mokelikeli ba bateng ea oli bo tsamaisane le boemo ba mokelikeli oa cadmium trichloride solution ka botlolong ea D, bula metsi a pholileng, 'me haeba ho hlokahala, tlohela metsi. molapo oa naetrojene o phalla kahare mme o laola sekhahla sa phallo ea eona ho bubble e le 1 motsotsoana. Nakong ea metsotso e 30, phahamisa mocheso oa bateng ea oli ho 155ºC, 'me u boloke mocheso ona ho fihlela 50 ml ea distillate e bokelloa, tlosa tube ea condenser ho tloha karolong ea likaroloana, hlatsoa ka metsi, hlatsoa 'me u kopane le metsi a bokelitsoeng, eketsa 3. marotholi a phenolphthalein indicator solution, 'me u sebelise Titrate ho fihlela pH ea boleng e le 6.9-7.1 (e lekanngoa ka meter ea acidity), rekota molumo o sebelisitsoeng V1 (mL), ebe u eketsa 0.5g ea sodium bicarbonate le 10mL ea dilute sulfuric acid, e tlohele. ema ho fihlela carbon dioxide e se e sa hlahisoa, eketsa 1.0g ea iodide ea potasiamo, e tiisa ka thata, e sisinye hantle, e behe sebakeng se lefifi ka metsotso e 5, eketsa 1mL ea tharollo ea starch indicator, titrate ho fihlela qetellong ka sodium thiosulfate titration. tharollo (0.02mol/L), 'me u tlalehe molumo o sebelisitsoeng oa V2 (mL). Tekong e 'ngoe e se nang letho, rekota li-volumes tsa Va le Vb (mL) tsa sodium hydroxide titration solution (0.02mol/L) le sodium thiosulfate titration solution (0.02mol/L) ka ho latellana. Bala litaba tsa hydroxypropoxyl.
Nako ea poso: Apr-14-2023