Hydroxypropyl methylcellulose (HPMC) wani abu ne mai narkewa da ruwa wanda ake amfani da shi sosai a magani, abinci, gini da sauran fannoni. Yana da kwanciyar hankali mai kyau na thermal, amma har yanzu yana iya raguwa a ƙarƙashin babban zafin jiki. Thearancin zafin jiki na HPMC yana shafar tsarinsa na ƙwayoyin cuta, yanayin muhalli (kamar zafi, ƙimar pH) da lokacin dumama.
Lalacewar zazzabi na HPMC
Rushewar thermal na HPMC yawanci yana farawa sama da 200℃, kuma a fili bazuwar zai faru tsakanin 250℃-300℃. Musamman:
Kasa da 100℃: HPMC galibi yana nuna ƙawancewar ruwa da canje-canje a cikin kaddarorin jiki, kuma babu lalacewa da ke faruwa.
100℃-200℃: HPMC na iya haifar da iskar iskar shaka ta bangare saboda karuwar yawan zafin jiki na gida, amma yana da karko gaba daya.
200℃-250℃: HPMC a hankali yana nuna lalatawar thermal, wanda galibi ana bayyana shi azaman karyewar tsari da sakin ƙananan ƙwayoyin ƙwayoyin cuta.
250℃-300℃: HPMC yana fuskantar bazuwar bayyane, launi ya zama duhu, ƙananan ƙwayoyin cuta kamar ruwa, methanol, acetic acid suna fitowa, kuma carbonization yana faruwa.
Sama da 300℃: HPMC yana raguwa da sauri kuma yana fitar da carbonizes, kuma wasu abubuwa marasa ƙarfi sun kasance a ƙarshe.
Abubuwan da ke shafar lalacewar HPMC
Nauyin kwayoyin halitta da matakin maye
Lokacin da nauyin kwayoyin halitta na HPMC ya girma, juriya na zafi yawanci yana da girma.
Matsayin maye gurbin methoxy da ƙungiyoyin hydroxypropoxy zai shafi kwanciyar hankali ta thermal. HPMC tare da babban digiri na musanya yana da sauƙi ƙasƙanta a yanayin zafi mai girma.
Abubuwan muhalli
Humidity: HPMC yana da ƙarfi hygroscopicity, kuma danshi na iya hanzarta lalacewa a babban yanayin zafi.
Ƙimar pH: HPMC ya fi sauƙi ga hydrolysis da lalacewa a ƙarƙashin ƙaƙƙarfan yanayin acid ko alkali.
Lokacin dumama
Zazzagewa zuwa 250℃na ɗan gajeren lokaci ba zai iya rushewa gaba ɗaya ba, yayin da yake riƙe da yawan zafin jiki na dogon lokaci zai hanzarta tsarin lalacewa.
Abubuwan lalata na HPMC
HPMC an samo shi ne daga cellulose, kuma samfuran lalacewa suna kama da cellulose. A lokacin aikin dumama, ana iya fitar da abubuwa masu zuwa:
Turin ruwa (daga kungiyoyin hydroxyl)
Methanol, ethanol (daga methoxy da hydroxypropoxy kungiyoyin)
Acetic acid (daga samfurori masu lalata)
Carbon oxides (CO, CO₂, samar da konewar kwayoyin halitta)
Ƙananan adadin coke saura
Aikace-aikacen zafi juriya na HPMC
Ko da yake HPMC sannu a hankali zai ragu sama da 200℃, yawanci ba a fallasa shi ga irin wannan yanayin zafi a ainihin aikace-aikace. Misali:
Masana'antar harhada magunguna: HPMC galibi ana amfani da ita don shafan kwamfutar hannu da wakilai masu dorewa, galibi ana sarrafa su a 60℃-80℃, wanda ya fi ƙasƙanci fiye da yanayin zafinsa.
Masana'antar abinci: Ana iya amfani da HPMC azaman mai kauri ko emulsifier, kuma yawan zafin jiki na yau da kullun bai wuce 100 ba.℃.
Masana'antar gine-gine: Ana amfani da HPMC azaman siminti da turmi mai kauri, kuma yawan zafin jiki na ginin bai wuce 80 ba.℃, kuma babu ƙasƙanci da zai faru.
HPMC ya fara rage darajar thermal sama da 200℃, yana raguwa sosai tsakanin 250℃-300℃, kuma carbonizes da sauri sama da 300℃. A aikace-aikace masu amfani, ya kamata a guje wa fallasa dogon lokaci zuwa yanayin zafi mai girma don kiyaye aikin sa.
Lokacin aikawa: Afrilu-03-2025