IHydroxypropyl methylcellulose (HPMC) sisixhobo sepolymer esinyibilikayo samanzi esisetyenziswa kakhulu kumayeza, ukutya, ulwakhiwo kunye namanye amasimi. Inozinzo oluhle lwe-thermal, kodwa isenokwehla phantsi kobushushu obuphezulu. Ubushushu bokuthotywa kweHPMC buchatshazelwa ikakhulu bubume bemolekyuli, iimeko zokusingqongileyo (ezifana nokufuma, ixabiso le-pH) kunye nexesha lokufudumeza.
Ukuthotywa kobushushu beHPMC
Ukuthotywa kobushushu beHPMC kudla ngokuqala ukuvela ngaphezulu kwama-200℃, kwaye ukubola okucacileyo kuya kwenzeka phakathi kwama-250℃-300℃. Ngokukodwa:
Ngaphantsi kwe-100℃: I-HPMC ibonisa ubukhulu becala ukuguquka kwamanzi kunye notshintsho kwiimpawu ezibonakalayo, kwaye akukho kwehla kwenzeka.
100℃-200℃: I-HPMC inokubangela inxenye ye-oxidation ngenxa yokwanda kobushushu bendawo, kodwa izinzile iyonke.
200℃-250℃: I-HPMC ngokuthe ngcembe ibonisa ukuthotywa kwe-thermal, ebonakaliswa ngokuyinhloko njengokuphuka kwesakhiwo kunye nokukhululwa kwee-volatiles ezincinci ze-molecular.
250℃-300℃: I-HPMC ifumana ukubola okucacileyo, umbala uba mnyama, iimolekyuli ezincinci ezifana namanzi, i-methanol, i-acetic acid iyakhululwa, kwaye i-carbonization iyenzeka.
Ngaphezulu kwama-300℃: I-HPMC iyancipha ngokukhawuleza kwaye i-carbonizes, kwaye ezinye izinto ezingabonakaliyo zihlala ekugqibeleni.
Izinto ezichaphazela ukuthotywa kweHPMC
Ubunzima bemolekyuli kunye neqondo lokutshintshwa
Xa ubunzima bemolekyuli ye-HPMC inkulu, ukuxhathisa ubushushu ngokuqhelekileyo kuphezulu.
Iqondo lokutshintshwa kwamaqela e-methoxy kunye ne-hydroxypropoxy kuya kuchaphazela ukuzinza kwayo kwe-thermal. I-HPMC eneqondo eliphezulu lokutshintshwa ithotywa ngokulula kumaqondo obushushu aphezulu.
Imiba yokusingqongileyo
Ukufuma: I-HPMC ine-hygroscopicity eyomeleleyo, kwaye ukufuma kunokukhawulezisa ukuthotywa kwayo kumaqondo obushushu aphezulu.
Ixabiso le-pH: I-HPMC ichaphazeleka ngakumbi kwi-hydrolysis kunye nokuthotywa phantsi kwe-asidi eqinile okanye iimeko ze-alkali.
Ixesha lokufudumeza
Ukufudumeza ukuya kwi-250℃ixesha elifutshane lingenakubola ngokupheleleyo, ngelixa ukugcina ukushisa okuphezulu ixesha elide kuya kukhawulezisa inkqubo yokuthotywa.
Iimveliso zokuthotywa kweHPMC
I-HPMC ithathwa ikakhulu kwi-cellulose, kwaye iimveliso zayo zokuthotywa ziyafana neselulosi. Ngexesha lenkqubo yokufudumeza, oku kulandelayo kunokukhutshwa:
Umphunga wamanzi (osuka kumaqela e-hydroxyl)
I-Methanol, i-ethanol (isuka kumaqela e-methoxy kunye ne-hydroxypropoxy)
Iacetic acid (ukusuka kwiimveliso zokubola)
Ii-carbon oxides (CO, CO₂, uveliswa kukutshiswa kwezinto eziphilayo)
Inani elincinci lentsalela yecoke
Ukumelana nobushushu besicelo se-HPMC
Nangona i-HPMC iya kuthotywa ngokuthe ngcembe ngaphezu kwe-200℃, ngokuqhelekileyo ayivezwanga kumaqondo obushushu aphezulu kangako kwizicelo ezizizo. Umzekelo:
Umzi-mveliso wamachiza: I-HPMC isetyenziswa ikakhulu ukugquma iipilisi kunye neearhente ezikhutshwa ngokuqhubekayo, ezidla ngokusebenza kuma-60.℃-80℃, ephantsi kakhulu kunokushisa kwayo kokuthotywa.
Ishishini lokutya: I-HPMC ingasetyenziswa njenge-thickener okanye i-emulsifier, kwaye ubushushu bokusetyenziswa obuqhelekileyo buhlala bungekho ngaphezu kwe-100.℃.
Umzi-mveliso wokwakha: I-HPMC isetyenziswa njengesamente nodaka, kwaye iqondo lobushushu bokwakha alidluli kuma-80.℃, yaye akukho kuthotywa kuya kwenzeka.
HPMC iqala ukuthomalalisa iqondo lokushisa ngaphezulu kwama-200℃, ibola kakhulu phakathi kwama-250℃-300℃, kwaye i-carbonizes ngokukhawuleza ngaphezu kwe-300℃. Kwizicelo eziphathekayo, ukubonakaliswa kwexesha elide kwindawo yokushisa okuphezulu kufuneka kugwenywe ukugcina ukusebenza kwayo okuzinzile.
Ixesha lokuposa: Apr-03-2025