Nā waiwai kemika a me ka synthesis o hydroxypropyl methylcellulose (HMPC)

ʻO ka Hydroxypropyl methylcellulose (HPMC) he polymer synthetic i loaʻa mai ka cellulose a hoʻohana mau ʻia e like me ka mānoanoa, emulsifier, a me ka stabilizer i nā ʻoihana like ʻole e like me ka meaʻai, nā lāʻau lapaʻau, a me nā mea hoʻonaninani. ʻO ka HMPC he mea hoʻoheheʻe hydroxypropylated o ka methylcellulose (MC), kahi wai-soluble nonionic cellulose ether i haku ʻia me nā ʻāpana methoxylated a me ka hydroxypropylated cellulose. Hoʻohana nui ʻia ka HMPC ma ke ʻano he excipient i loko o nā ʻano lāʻau lapaʻau ma muli o kona nontoxicity, biocompatibility, a me ka biodegradability.

HMPC waiwai kemika:

Hoʻopili ʻia nā waiwai kemika o ka HMPC i ka hiki ʻana o nā hui hydroxyl a me ether i loko o kāna ʻano mole. Hiki ke hoʻohana ʻia nā pūʻulu hydroxyl o cellulose ma o nā hopena kemika like ʻole, e like me ka etherification, esterification, a me ka oxidation, e hoʻokomo i nā hui hana like ʻole i loko o ka iwi kuamoʻo polymer. Loaʻa i ka HMPC nā pūʻulu methoxy (-OCH3) a me hydroxypropyl (-OCH2CHOHCH3), hiki ke mālama ʻia e hāʻawi i nā waiwai like ʻole e like me ka solubility, viscosity a me ka gelation.

Hiki ke hoʻoheheʻe ʻia ka HMPC i loko o ka wai, e hana ana i nā ʻoluʻolu a me ka viscous ma nā haʻahaʻa haʻahaʻa. Hiki ke hoʻololi ʻia ka viscosity o nā hāʻina HMPC ma ka hoʻoponopono ʻana i ke degere o ka hoʻololi ʻana (DS) o nā pūʻulu hydroxypropyl, ka mea e hoʻoholo ai i ka helu o nā wahi hydroxyl i hoʻololi ʻia no ka ʻāpana glucose. ʻO ke kiʻekiʻe o ka DS, ʻoi aku ka haʻahaʻa o ka solubility a ʻoi aku ka kiʻekiʻe o ka viscosity o ka solution HMPC. Hiki ke hoʻohana ʻia kēia waiwai no ka mālama ʻana i ka hoʻokuʻu ʻana o nā mea hoʻoikaika mai nā hana lāʻau lapaʻau.

Hōʻike pū ka HMPC i ke ʻano pseudoplastic, ʻo ia hoʻi ka emi ʻana o ka viscosity me ka piʻi ʻana o ka shear rate. Hana kēia waiwai i mea kūpono e like me ka mānoanoa no nā hoʻoheheʻe wai e pono ai ke kū i ka ikaika shear i ka wā o ka hoʻoili ʻana a i ʻole nā ​​noi.

Paʻa ka HMPC a hiki i kahi mahana, ma luna aʻe e hoʻomaka ai e hoʻohaʻahaʻa. ʻO ka mahana hoʻohaʻahaʻa o ka HMPC e pili ana i ka DS a me ka ʻike o ka polymer i loko o ka hopena. Hōʻike ʻia ka pae wela hoʻohaʻahaʻa o HMPC he 190-330°C.

Hoʻohui o HMPC:

Hoʻohui ʻia ka HMPC e ka hopena etherification o cellulose me ka propylene oxide a me ka methylethylene oxide i mua o kahi catalyst alkaline. Hoʻomaka ka hopena ma nā ʻanuʻu ʻelua: ʻo ka mua, ua pani ʻia nā pūʻulu methyl o cellulose e propylene oxide, a laila hoʻololi hou ʻia nā pūʻulu hydroxyl e ka methyl ethylene oxide. Hiki ke ho'omalu 'ia ka DS o ka HMPC ma ka ho'ololi 'ana i ka ratio molar o propylene oxide i cellulose i ka wā o ka hana synthesis.

Hoʻokō pinepine ʻia ka hopena i loko o kahi ʻano wai i ka wela a me ke kaomi kiʻekiʻe. ʻO ka mea hoʻoheheʻe maʻamau ka sodium a i ʻole potassium hydroxide, kahi e hoʻonui ai i ka reactivity o nā pūʻulu cellulose hydroxyl i nā apo epoxide o propylene oxide a me methylethylene oxide. Hoʻopau ʻia ka huahana hopena, holoi a maloʻo no ka loaʻa ʻana o ka huahana HMPC hope loa.

Hiki ke hoʻohui pū ʻia ka HMPC ma ka hana ʻana i ka cellulose me ka propylene oxide a me ka epichlorohydrin i mua o nā catalysts acid. Hoʻohana ʻia kēia ʻano hana, i kapa ʻia ʻo ka epichlorohydrin process, e hana i nā derivatives cellulose cationic, i hoʻopiʻi maikaʻi ʻia ma muli o ka loaʻa ʻana o nā hui ammonium quaternary.

i ka hopena:

ʻO ka HMPC he polymer multifunctional me nā waiwai kemika maikaʻi loa i kūpono no nā noi like ʻole i nā ʻoihana like ʻole. ʻO ka synthesis o ka HMPC e pili ana i ka hopena etherification o cellulose me ka propylene oxide a me ka methylethylene oxide ma ke alo o kahi catalyst alkaline a i ʻole kahi catalyst acidic. Hiki ke hoʻopaʻa ʻia nā waiwai o ka HMPC ma o ka hoʻomalu ʻana i ka DS a me ka neʻe ʻana o ka polymer. ʻO ka palekana a me ka biocompatibility o ka HMPC e lilo ia i mea koho maikaʻi no nā ʻano lāʻau lapaʻau.