Hydroxypropyl methylcellulose (HPMC) he hui polymer hiki ole i ka wai-ionic i loaa ma ka hoololi kemika o ka cellulose maoli. Hoʻohana nui ʻia ia i ka meaʻai, ka lāʻau lapaʻau, nā mea hoʻonaninani a me nā ʻoihana kūkulu, ʻoi aku hoʻi ma ke ʻano he adhesive, thickener, emulsifier a me ka suspending agent i ka hoʻomākaukau lāʻau. I ke kaʻina hana noi, ʻo nā hiʻohiʻona viscosity o ka HPMC aqueous solution he mea koʻikoʻi i kāna hana ma nā kahua like ʻole.
1. Ka hale a me nā waiwai o ka hydroxypropyl methylcellulose
ʻO ka molecular structure o HPMC he ʻelua pūʻulu pani, hydroxypropyl (-CH₂CHOHCH₃) a me ka methyl (-OCH₃), ka mea e loaʻa ai ka hiki ke hoʻololi i ka wai maikaʻi. Loaʻa i ke kaulahao molekole HPMC kekahi ʻano paʻa, akā hiki iā ia ke hana i kahi ʻano pūnaewele ʻekolu-dimensional i loko o ka hoʻonā wai, e hoʻonui ai i ka viscosity. ʻO kona kaumaha molekala, ʻano mea pani a me ke degere o ka hoʻololi ʻana (ʻo ia hoʻi, ke degere o ka hydroxypropyl a me ka methyl substitution o kēlā me kēia ʻāpana) he mana koʻikoʻi i ka viscosity o ka hopena.
2. Nā hiʻohiʻona viscosity o ka hoʻonā wai
ʻO nā hiʻohiʻona viscosity o ka HPMC aqueous solution e pili pono ana i nā mea e like me ka hoʻopaʻa ʻana, ke kaumaha molekala, ka mahana a me ka waiwai pH o ka solvent. ʻO ka mea maʻamau, piʻi ka viscosity o ka hoʻonā wai wai HPMC me ka piʻi ʻana o kona ʻike. Hōʻike kona viscosity i ke ʻano rheological non-Newtonian, ʻo ia hoʻi, i ka piʻi ʻana o ka shear rate, e emi mālie ka viscosity o ka hoʻonā, e hōʻike ana i kahi ʻano shear thinning.
(1) Ka hopena o ka noonoo
Aia kekahi pilina ma waena o ka viscosity o ka HPMC aqueous solution a me kona hoʻopaʻa ʻana. Ke piʻi aʻe ka manaʻo o ka HPMC, hoʻonui ʻia ka pilina molekala i loko o ka wai wai, a hoʻonui ka entanglement a me ka hoʻopili ʻana o nā kaulahao molekala, e hoʻonui ai i ka viscosity o ka hopena. Ma nā haʻahaʻa haʻahaʻa, hoʻonui ka viscosity o ka HPMC aqueous solution me ka piʻi ʻana o ka noʻonoʻo, akā i nā kiʻekiʻe kiʻekiʻe, ʻo ka ulu ʻana o ka viscosity o ka hopena e maʻalahi a paʻa a hiki i kahi waiwai paʻa.
(2) Ka hopena o ke kaumaha mole
Hoʻopili pololei ke kaumaha molekala o HPMC i ka viscosity o kāna ʻano wai. ʻO ka HPMC me ke kaumaha molekala kiʻekiʻe he mau kaulahao molekala lōʻihi a hiki ke hana i kahi hoʻolālā pūnaewele ʻekolu-dimensional paʻakikī i loko o ka hoʻonā wai, e hopena i ka viscosity kiʻekiʻe. ʻO ka hoʻohālikelike ʻana, ʻo HPMC me ka haʻahaʻa haʻahaʻa molekala ʻoi aku ka haʻahaʻa o ka ʻōnaehana pūnaewele a me ka viscosity haʻahaʻa ma muli o kāna mau kaulahao molekala pōkole. No laila, i ka wā e noi ai, he mea nui e koho i ka HPMC me kahi paona molekala kūpono e hoʻokō ai i ka hopena viscosity kūpono.
(3) Ka hopena o ka wela
He mea koʻikoʻi ka mahana e pili ana i ka viscosity o ka wai wai HPMC. Ke piʻi aʻe ka mahana, hoʻoikaika ka neʻe ʻana o nā molekala wai a emi mau ka viscosity o ka hopena. ʻO kēia ke kumu i ka piʻi ʻana o ka mahana, piʻi ke kūʻokoʻa o ke kaulahao mole HPMC a nāwaliwali ka pilina ma waena o nā molekala, a laila e hōʻemi i ka viscosity o ka hopena. Eia nō naʻe, ʻokoʻa paha ka pane ʻana o HPMC mai nā ʻāpana like ʻole a i ʻole nā mea hoʻohana i ka mahana, no laila pono e hoʻoponopono ʻia nā kūlana wela e like me nā koi noi kikoʻī.
(4) Ka hopena o ka waiwai pH
ʻO ka HPMC ponoʻī he pūhui non-ionic, a ʻo ka viscosity o kāna hoʻonā wai e maʻalahi i nā loli i ka pH. ʻOiai ke hōʻike nei ka HPMC i nā hiʻohiʻona viscosity paʻa i loko o nā kaiapuni ʻawaʻawa a kū ʻole paha, e hoʻopili ʻia ka solubility a me ka viscosity o HPMC ma nā wahi ʻawaʻawa a i ʻole ka alkaline. No ka laʻana, ma lalo o ka waikawa ikaika a i ʻole nā kūlana alkaline ikaika, hiki ke hoʻohaʻahaʻa ʻia nā molekala HPMC, a laila e hōʻemi ana i ka viscosity o kāna ʻano wai.
3. Rheological kālailai o viscosity ano o ka HPMC aqueous solution
Hōʻike maʻamau ka ʻano rheological o ka wai wai HPMC i nā hiʻohiʻona wai non-Newtonian, ʻo ia hoʻi, ʻaʻole pili wale kona viscosity i nā mea e like me ka neʻe ʻana o ka hoʻonā a me ke kaumaha molekala, akā no ka shear rate. Ma ka ʻōlelo maʻamau, ma ka haʻahaʻa haʻahaʻa, ʻo ka HPMC aqueous solution e hōʻike ana i ka viscosity kiʻekiʻe, ʻoiai e piʻi ana ka nui o ka shear rate, e emi ana ka viscosity. Kapa ʻia kēia ʻano "shear thinning" a i ʻole "shear thinning" a he mea koʻikoʻi loa ia i nā hana pono he nui. No ka laʻana, ma ke kahua o ka uhi, hoʻomākaukau lāʻau lapaʻau, hana meaʻai, a me nā mea ʻē aʻe, hiki i nā hiʻohiʻona shear thinning o HPMC ke hōʻoia i ka mālama ʻia ʻana o ka viscosity kiʻekiʻe i ka wā o nā noi haʻahaʻa, a hiki ke kahe maʻalahi ma lalo o nā kūlana shear kiʻekiʻe.
4. ʻO nā kumu ʻē aʻe e pili ana i ka viscosity o ka wai wai HPMC
(1) Ka hopena o ka paʻakai
ʻO ka hoʻohui ʻana i nā solutes paʻakai (e like me ka sodium chloride) hiki ke hoʻonui i ka viscosity o HPMC aqueous solution. ʻO kēia no ka mea hiki i ka paʻakai ke hoʻonui i ka pilina ma waena o nā molekala ma o ka hoʻololi ʻana i ka ikaika ionic o ka hopena, i mea e hana ai nā molekala HPMC i kahi ʻoihana pūnaewele paʻa, a laila e hoʻonui ai i ka viscosity. Eia nō naʻe, pono e hoʻoponopono ʻia ka hopena o ke ʻano paʻakai a me ka noʻonoʻo ʻana i ka viscosity e like me nā kūlana kūikawā.
(2) Ka hopena o nā mea hoʻohui ʻē aʻe
ʻO ka hoʻohui ʻana i nā mea hoʻohui ʻē aʻe (e like me nā surfactants, polymers, etc.) i ka hoʻonā wai wai HPMC e hoʻopilikia pū i ka viscosity. No ka laʻana, hiki i nā surfactants ke hoʻemi i ka viscosity o HPMC, ʻoi loa ke kiʻekiʻe o ka ʻike surfactant. Eia kekahi, hiki i kekahi mau polymers a i ʻole nā palapala ke launa pū me HPMC a hoʻololi i nā waiwai rheological o kāna hopena.
ʻO nā hiʻohiʻona viscosity ohydroxypropyl methylcellulose Hoʻopili ʻia ka hopena wai e nā kumu he nui, e like me ka noʻonoʻo ʻana, ke kaumaha molekala, ka mahana, ka waiwai pH, a me nā mea ʻē aʻe. Hōʻike pinepine ʻia ka wai wai HPMC i nā waiwai rheological non-Newtonian, maikaʻi ka mānoanoa a me ka shear thinning waiwai, a hoʻohana nui ʻia i nā ʻano ʻoihana a me nā lāʻau lapaʻau. ʻO ka hoʻomaopopo ʻana a me ka ʻike ʻana i kēia mau hiʻohiʻona viscosity e kōkua i ka hoʻohana ʻana i ka HPMC i nā noi like ʻole. Ma nā noi kūpono, pono e koho ʻia ke ʻano HPMC kūpono a me nā kūlana kaʻina e like me nā pono kikoʻī e loaʻa ai ka viscosity kūpono a me nā waiwai rheological.
Ka manawa hoʻouna: Mar-01-2025