I-HPMC izowohloka ngaliphi izinga lokushisa?

I-Hydroxypropyl methylcellulose (HPMC) iyinto ye-polymer encibilika emanzini esetshenziswa kabanzi kwezokwelapha, ukudla, ukwakha kanye neminye imikhakha. Inokuzinza okuhle kokushisa, kodwa ingase yonakale ngaphansi kokushisa okuphezulu. Izinga lokushisa lokuwohloka kwe-HPMC lithinteka kakhulu yisakhiwo sayo sama-molecule, izimo zemvelo (njengomswakama, inani le-pH) kanye nesikhathi sokushisa.

Izinga lokushisa lokubola kwe-HPMC

Ukwehla kokushisa kwe-HPMC kuvame ukuqala ukubonakala ngaphezu kwama-200℃, futhi ukubola okusobala kuzokwenzeka phakathi kuka-250℃-300℃Ngokuqondile:

Ngaphansi kwe-100℃: I-HPMC ikhombisa kakhulu ukuhwamuka kwamanzi kanye nezinguquko ezakhiweni zomzimba, futhi akukho ukuwohloka okwenzekayo.

100℃-200℃: I-HPMC ingabangela ukubola okungaphelele ngenxa yokwenyuka kwezinga lokushisa lendawo, kodwa iyonke izinzile.

200℃-250℃: I-HPMC kancane kancane ikhombisa ukuwohloka kokushisa, okubonakaliswa kakhulu njengokuqhekeka kwesakhiwo kanye nokukhululwa kwezinto ezincane eziguquguqukayo zama-molecule.

250℃-300℃: I-HPMC ibola ngokusobala, umbala uba mnyama, kukhishwa ama-molecule amancane njengamanzi, i-methanol, i-acetic acid, bese kuba khona i-carbonization.

Ngaphezulu kwama-300℃: I-HPMC yonakala ngokushesha futhi ibe yi-carbon, kanti ezinye izinto ezingaphili zihlala ekugcineni.

Izici ezithinta ukuwohloka kwe-HPMC

Isisindo sama-molecule kanye nezinga lokushintshana

Uma isisindo sama-molecule se-HPMC sikhulu, ukumelana kwayo nokushisa kuvame ukuba phezulu.

Izinga lokushintshaniswa kwamaqembu e-methoxy kanye ne-hydroxypropoxy lizothinta ukuzinza kwayo kokushisa. I-HPMC enezinga eliphezulu lokushintshaniswa ilula kakhulu emazingeni okushisa aphezulu.

Izici zemvelo

Umswakama: I-HPMC ine-hygroscopicity enamandla, futhi umswakama ungasheshisa ukuwohloka kwayo emazingeni okushisa aphezulu.

Inani le-pH: I-HPMC isengozini enkulu yokulahlekelwa yi-hydrolysis kanye nokuwohloka ngaphansi kwezimo ezinamandla ze-asidi noma ze-alkali.

Isikhathi sokushisa

Ukushisa kufikela ku-250℃isikhathi esifushane kungase kungaboli ngokuphelele, kuyilapho ukugcina izinga lokushisa eliphakeme isikhathi eside kuzosheshisa inqubo yokubola.

Imikhiqizo yokuwohloka kwe-HPMC

I-HPMC itholakala kakhulu ku-cellulose, futhi imikhiqizo yayo yokuwohloka ifana ne-cellulose. Ngesikhathi senqubo yokushisa, okulandelayo kungakhishwa:

Umhwamuko wamanzi (ovela kumaqembu e-hydroxyl)

I-Methanol, i-ethanol (evela emaqenjini e-methoxy kanye ne-hydroxypropoxy)

I-Acetic acid (evela emikhiqizweni yokubola)

Ama-carbon oxide (CO2, CO2₂, okukhiqizwa ukushiswa kwezinto eziphilayo)

Inani elincane le-coke residue

Ukumelana nokushisa kwesicelo se-HPMC

Nakuba i-HPMC izokwehla kancane kancane ibe ngaphezu kwama-200℃, ngokuvamile ayivezwa emazingeni okushisa aphezulu kangako ekusetshenzisweni kwangempela. Isibonelo:

Imboni Yezemithi: I-HPMC isetshenziswa kakhulu ekumbozeni amaphilisi kanye nezinto ezikhipha isikhathi eside, ngokuvamile ezisebenza ku-60℃-80℃, okuphansi kakhulu kunezinga lokushisa layo lokuwohloka.

Imboni yokudla: I-HPMC ingasetshenziswa njengesithambisi noma i-emulsifier, futhi izinga lokushisa lokusetshenziswa elivamile ngokuvamile alidluli ku-100℃.

Imboni yokwakha: I-HPMC isetshenziswa njengesithako sokujiya usimende nodaka, futhi izinga lokushisa lokwakha ngokuvamile alidluli ku-80℃, futhi akukho ukuwohloka okuzokwenzeka.

I-HPMC iqala ukuwohloka ngokushisa ngaphezu kwama-200℃, ibola kakhulu phakathi kuka-250℃-300℃, futhi i-carbonize ngokushesha ngaphezu kwama-300℃Ezisetshenzisweni ezisebenzayo, ukuchayeka isikhathi eside endaweni enokushisa okuphezulu kufanele kugwenywe ukuze kugcinwe ukusebenza kwayo okuzinzile.