ʻO ka maʻamau, i ka synthesis ohydroxypropyl methylcellulose, Hoʻomaʻamaʻa ʻia ka pulupulu cellulose i hoʻomaʻemaʻe ʻia me ka hopena alkali ma 35-40 ° C no ka hapalua hola, ʻoki ʻia, ʻāwīwī ʻia ka cellulose, a me nā makahiki kūpono i 35 ° C, no laila ʻo ka loaʻa ʻana o nā fiber alkali he awelika polymerized degere i loko o ka pono. laula. E hoʻokomo i ka fiber alkali i loko o ka ipu etherification, e hoʻohui i ka propylene oxide a me ka methyl chloride i ka huli ʻana, a etherify ma 50-80 ℃ no 5 mau hola i kahi kaomi kiʻekiʻe ma kahi o 1.8 MPa. 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 holoi i ka mea e hoʻonui ai i ka leo. Dehydrate me ka centrifuge. Holoi a hiki i ke kūʻokoʻa, ke emi ka wai i loko o ka mea ma lalo o 60%, e hoʻomaloʻo me ke kahe ea wela ma 130 ° C a emi iho ma mua o 5%.
Alkalization: Hoʻohui ʻia ka pulupulu i hoʻomaʻemaʻe ʻia ma hope o ka wehe ʻana i loko o kahi solvent inert, a hoʻāla ʻia me ka alkali a me ka wai palupalu e pehu ai i ka lattice kristal o ka pulupulu i hoʻomaʻemaʻe ʻia, kahi e kūpono ai i ke komo ʻana o nā molekele etherifying agent a hoʻomaikaʻi i ka kūlike o ka hopena etherification. . ʻO ka alkali i hoʻohana ʻia i ka alkaliization he metala hydroxide a i ʻole kahi kumu kūlohelohe. ʻO ka nui o ka alkali i hoʻohui ʻia (e like me ka nui ma lalo) he 0.1-0.6 mau manawa o ka pulupulu i hoʻomaʻemaʻe ʻia, a ʻo ka nui o ka wai palupalu he 0.3-1.0 mau manawa o ka pulupulu hoʻomaʻemaʻe; ʻO ka solvent inert ka hui ʻana o ka waiʻona a me ka hydrocarbon, a ʻo ka nui o ka solvent inert i hoʻohui ʻia he pulupulu hoʻomaʻemaʻe. 7-15 mau manawa: hiki i ka mea hoʻoheheʻe inert ke lilo i waiʻona me 3-5 carbon atoms (e like me ka waiʻona, propanol), acetone. Hiki ke lilo i aliphatic hydrocarbons a me aromatic hydrocarbons; pono e hoʻomaluʻia ka mahana i loko o 0-35 ° C i ka wā o ka alkalization; ʻO ka manawa alkaliization ma kahi o 1hr. Hiki ke hoʻoholo ʻia ka hoʻoponopono ʻana o ka mahana a me ka manawa e like me nā koi o ka mea a me ka huahana.
Etherification: Ma hope o ka hoʻomaʻamaʻa alkalization, ma lalo o nā kūlana vacuum, e hoʻokō ʻia ka etherification ma ka hoʻohui ʻana i kahi mea etherifying, a ʻo ka etherifying agent ka propylene oxide. I mea e hōʻemi ai i ka hoʻohana ʻana i ka mea hoʻoheheʻe etherifying, ua hoʻohui ʻia ka etherifying agent i ʻelua mau manawa i ka wā o ka etherification.
Ka manawa hoʻouna: Apr-28-2024