Hydroxypropyl methylcellulose (HPMC) he wai-soluble polymer mea i hoʻohana nui ʻia i ka lāʻau lapaʻau, ka meaʻai, ke kūkulu ʻana a me nā māla ʻē aʻe. Loaʻa iā ia ka paʻa wela maikaʻi, akā hiki ke hoʻohaʻahaʻa ʻia ma lalo o ka wela kiʻekiʻe. Hoʻopili nui ʻia ka mahana hoʻohaʻahaʻa o HPMC e kona ʻano molekala, nā kūlana kaiapuni (e like me ka haʻahaʻa, ka waiwai pH) a me ka manawa hoʻomehana.
ʻO ka wela hoʻohaʻahaʻa o HPMC
Hoʻomaka ka hoʻohaʻahaʻa wela o ka HPMC ma luna o 200℃, a e ʻike ʻia ka palaho ma waena o 250℃-300℃. Kūkākūkā:
Ma lalo o 100℃: Hōʻike nui ka HPMC i ka hoʻoheheʻe ʻana o ka wai a me nā hoʻololi ʻana i nā waiwai kino, a ʻaʻohe mea hōʻino.
100℃-200℃: Hiki paha i ka HPMC ke ho'ohehe'e 'ia ma muli o ka pi'i 'ana o ka mahana, akā pa'a loa.
200℃-250℃: Hōʻike mālie ka HPMC i ka hoʻohaʻahaʻa wela, ka mea i hōʻike nui ʻia ma ke ʻano he haʻihaʻi hale a me ka hoʻokuʻu ʻana o nā molekala liʻiliʻi.
250℃-300℃: Loaʻa ka HPMC i ka decomposition maopopo, lilo ka waihoʻoluʻu i ʻeleʻele, hoʻokuʻu ʻia nā molekole liʻiliʻi e like me ka wai, methanol, acetic acid, a loaʻa ka carbonization.
Ma luna o 300℃: Hoʻohaʻahaʻa koke ʻia ka HPMC a hoʻoneʻe ʻia ka carbonizes, a koe kekahi mau mea inorganic i ka hopena.
Nā mea e pili ana i ka hoʻohaʻahaʻa HPMC
Kaumaha molekula a me ke degere o ka hoʻololi
Ke nui ka paona molekala o HPMC, kiʻekiʻe ke kūpaʻa wela.
ʻO ka pae o ka hoʻololi ʻana o nā pūʻulu methoxy a me hydroxypropoxy e hoʻopilikia i kona kūpaʻa wela. ʻOi aku ka maʻalahi o ka hoʻohaʻahaʻa ʻia ʻana o ka HPMC me kahi kiʻekiʻe o ka hoʻololi ʻana i nā wela kiʻekiʻe.
Nā kumu kaiapuni
Ka haʻahaʻa: He hygroscopicity ikaika ka HPMC, a hiki i ka makū ke hoʻokē i kona hoʻohaʻahaʻa ʻana i nā wela kiʻekiʻe.
Waiwai pH: ʻoi aku ka maʻalahi o ka HPMC i ka hydrolysis a me ka hoʻohaʻahaʻa ʻana ma lalo o nā kūlana waika ikaika a i ʻole ka alkali.
Ka manawa hoʻomehana
Hoʻomoʻa i ka 250℃no ka manawa pōkole ʻaʻole hiki ke hoʻopau loa, ʻoiai ka mālama ʻana i ka mahana kiʻekiʻe no ka manawa lōʻihi e hoʻolōʻihi i ke kaʻina degradation.
Nā huahana degradation o HPMC
Loaʻa ka HPMC mai ka cellulose, a ua like nā huahana degradation me cellulose. I ka wā o ka hoʻomehana ʻana, hiki ke hoʻokuʻu ʻia kēia mau mea:
ʻO ka mahu wai (mai nā pūʻulu hydroxyl)
Methanol, ethanol (mai nā hui methoxy a me hydroxypropoxy)
Acetic acid (mai nā huahana decomposition)
ʻO nā kalapona kalapona (CO, CO₂, i hana ʻia e ka puhi ʻana i nā mea ola)
He wahi koena coke
Noi ka wela o ka HPMC
ʻOiai e hoʻohaʻahaʻa mālie ka HPMC ma luna o 200℃, ʻaʻole i ʻike pinepine ʻia i nā wela kiʻekiʻe i nā noi maoli. ʻo kahi laʻana:
ʻOihana lāʻau lapaʻau: Hoʻohana nui ʻia ʻo HPMC no ka uhi ʻana i ka papa a me nā mea hoʻokuʻu hoʻomau mau, hana maʻamau ma 60℃-80℃, ʻoi aku ka haʻahaʻa ma mua o kona wela degradation.
ʻOihana meaʻai: Hiki ke hoʻohana ʻia ka HPMC e like me ka mānoanoa a i ʻole emulsifier, a ʻo ka mahana hoʻohana maʻamau ʻaʻole ma mua o 100.℃.
ʻOihana hana: Hoʻohana ʻia ʻo HPMC ma ke ʻano he sima a me ka mortar thickener, a ʻaʻole ʻoi aku ka mahana o ke kūkulu ʻana ma mua o 80℃, a ʻaʻole e hōʻino ʻia.
HPMC hoʻomaka e hoʻohaʻahaʻa i ka wela ma luna o 200℃, decomposes nui ma waena o 250℃-300℃, a hiki ke kalapona ma luna o 300℃. Ma nā noi kūpono, pono e pale ʻia ka ʻike lōʻihi i ke kaiapuni wela e mālama i kāna hana paʻa.
Ka manawa hoʻouna: Apr-03-2025