ʻO ka maikaʻi o ka Hydroxypropyl Methyl Cellulose

Hoʻomaʻemaʻe ʻia ʻo Hydroxypropyl methylcellulose mai ka pulupulu ma hope o ka alkalization, me ka hoʻohana ʻana i ka propylene oxide a me ka methyl chloride ma ke ʻano he etherification agents, a ke hana nei i kahi ʻano hopena e hana ai i ka non-ionic cellulose i hui ʻia eter. ʻO ka Hydroxypropyl methylcellulose he ether cellulose non-ionic, keʻokeʻo i ka helehelena, ʻaʻohe ʻono a ʻono ʻole. ʻO ke kūlana o ka hoʻololi ʻana ma ke ʻano maʻamau . ʻOkoʻa kona mau waiwai ma muli o ka ratio o ka methoxyl content i ka hydroxypropyl content.

ʻO ka mua, e nānā mua i ka synthesis o hydroxypropyl methylcellulose:

Hoʻomaʻamaʻa ʻia ka pulupulu cellulose i hoʻomaʻemaʻe ʻia me ka hopena alkali ma 35-40 ° C no ka hapalua hola, kaomi ʻia, a hoʻopau ʻia ka cellulose ma 35 ° C a ʻelemakule pono, no laila ke degere awelika o ka polymerization o ka fiber alkali i loaʻa i loko o ka. ka laulā i makemake ʻia. E hoʻokomo i ka fiber alkali i loko o ka pahu etherification, e hoʻohui i ka propylene oxide a me ka methyl chloride i ke kaʻina, etherify ma 50-80 ° C no 5 mau hola, a ʻo ke kaomi kiʻekiʻe he approx. A laila e hoʻohui i ka nui kūpono o ka waika hydrochloric a me ka waikawa oxalic i ka wai wela ma 90 ° C e hoʻonui i ka leo. Dehydrate i loko o kahi centrifuge. Ke emi ka makū o ka mea ma lalo o 60%, e holoi iā ia i kū ʻole, a laila e hoʻomaloʻo iā ia ma lalo o 5% me kahi kahe ea wela ma 130 ° C. ʻO ka hope ua wāwahi ʻia ma kahi kānana 20-mesh e loaʻa ai ka huahana i hoʻopau ʻia.

Nā hiʻohiʻona o ka Hydroxypropyl Methyl Cellulose:

1. Hiki ke hoʻoheheʻe ʻia ka Hydroxypropyl methylcellulose i ka wai anuanu a e hoʻoheheʻe ʻia i ka wai wela. Eia nō naʻe, ʻoi aku ka kiʻekiʻe o ka mahana gelation i ka wai wela ma mua o ka methylcellulose. Hoʻomaikaʻi maikaʻi ʻia ka hoʻohemo ʻana i ka wai anuanu ma mua o ka methyl cellulose.

2. ʻO ka viscosity o ka hydroxypropyl methylcellulose e pili ana i ke kaumaha mole, a kiʻekiʻe ka viscosity i ka nui o ke kaumaha mole. Hoʻopili ka mahana i kona viscosity, i ka piʻi ʻana o ka mahana, emi ka viscosity. Akā ʻoi aku ka haʻahaʻa o kona viscosity ma mua o ka methyl cellulose. Paʻa kona hopena i ka mahana wela.

ʻO ka mana paʻa wai o ka hydroxypropyl methylcellulose e pili ana i kona nui hoʻohui, viscosity, etc., a ʻoi aku ka kiʻekiʻe o ka paʻa wai ma mua o ka methyl cellulose.

3. He kūpaʻa ka Hydroxypropyl methylcellulose i ka waika a me ka alkali, a ua kūpaʻa kona ʻano wai ma ka laulā o ka pH=2-12. He liʻiliʻi ka hopena o ka soda a me ka wai lime i kona mau waiwai, akā hiki i ka alkali ke hoʻolalelale i kona hoʻoheheʻe ʻana a hoʻonui iki i kona viscosity. ʻO ka Hydroxypropyl methylcellulose paʻa i nā paʻakai maʻamau, akā i ka wā i kiʻekiʻe ai ka paʻakai o ka wai paʻakai, piʻi ka viscosity o ka hydroxypropyl methylcellulose solution.

4. Hiki ke hoʻohuiʻia ka Hydroxypropyl methylcellulose me nā polymers hiki ke hoʻoheheʻeʻia i ka wai e hana i kahiʻano likeʻole, kiʻekiʻe-viscosity solution. E like me ka waiʻona polyvinyl, ka pauka wai wai eter, ka ʻōpala meaʻai, etc.

ʻOi aku ka maikaʻi o ke kūpaʻa ʻana o ka enzyme hydroxypropyl methylcellulose ma mua o ka methylcellulose, a ʻoi aku ka liʻiliʻi o kāna hoʻonā ʻana i ka enzymatically degraded ma mua o ka methylcellulose.

5. ʻOi aku ka kiʻekiʻe o ka hoʻopili ʻana ma waena o ka hydroxypropyl methylcellulose a me ka mortar ma mua o ka methylcellulose.

ʻO ka mortar wet-mixed he sima, ka hui maikaʻi, nā mea hoʻohui a me ka wai, a ua hoʻoholo ʻia nā ʻāpana like ʻole e like me ka hana. Ma hope o ke ana ʻia ʻana o ka hui ʻana a hui pū ʻia i kekahi ratio ma ke kahua hui ʻana, lawe ʻia ka hui ʻana i kahi e hoʻohana ʻia e kahi kaʻa huila a mālama ʻia i loko o kahi pahu kūikawā, a hoʻohana ʻia ka hui ʻana i loko o kahi manawa i ʻōlelo ʻia.

Pehea e hoʻoholo ai i ka maikaʻi o ka hydroxypropyl methylcellulose?

ʻO ka hoʻoholo ʻana i ka maikaʻi o ka hydroxypropyl methylcellulose e hilinaʻi nui ʻia ma nā hōʻailona ʻelua, ʻo ka degere o ka hoʻololi ʻana (DS) a ʻo ka maʻemaʻe kekahi. ʻO ka mea maʻamau, ʻokoʻa nā waiwai o ka carboxymethyl cellulose inā ʻokoʻa ke degere o ka hoʻololi ʻana; ʻoi aku ka kiʻekiʻe o ke kiʻekiʻe o ka hoʻololi ʻana, ʻoi aku ka ikaika o ka solubility, a ʻoi aku ka maikaʻi o ka ʻike a me ka paʻa o ka hopena. Wahi a nā moʻolelo pili, ʻoi aku ka maikaʻi o ka ʻike ʻana o ka carboxymethyl cellulose i ka wā o ke kiʻekiʻe o ka hoʻololi ʻana he ~, a kiʻekiʻe ka viscosity o kāna hoʻonā wai ke kiʻekiʻe ka pH waiwai 6-9. ʻO ia hoʻi, no ke ana ʻana i ka maikaʻi o ka carboxymethyl cellulose, pono e ʻike maikaʻi i kona degere o ka hoʻololi a me ka maʻemaʻe. Hoʻokō kēia mau hōʻailona ʻelua i nā koi, ʻo ia hoʻi he maikaʻi loa kona ʻano.