Kounga o Hydroxypropyl Methyl Cellulose

Ko te Hydroxypropyl methylcellulose ka parahia mai i te miro i muri i te whakamaaramatanga, ma te whakamahi i te propylene oxide me te methyl chloride hei maatete whakamaarama, ka puta he raupapa o nga tauhohenga ki te whakaputa i te cellulose katote-kore ether. Ko te Hydroxypropyl methylcellulose he ether cellulose kore-ionic, he ma te ahua, he kakara, he kore reka. Ko te tohu whakakapinga ko te tikanga. He rereke ona ahuatanga i runga i te ōwehenga o te ihirangi methoxyl ki te ihirangi hydroxypropyl.

Tuatahi, titiro tuatahi ki te whakahiatotanga o te hydroxypropyl methylcellulose:

Ko te cellulose miro parakore ka tukuna ki te otinga kawakore i te 35-40°C mo te hawhe haora, ka pehia, ka nukuhia te cellulose ki te 35°C me te pai o te koroheketanga, kia noho ai te tohu toharite o te polymerization o te muka kawakore i roto i te awhe e hiahiatia ana. Kuhua te muka kawakore ki roto i te tank etherification, tāpiri propylene oxide me te methyl pūhaumāota i roto i te raupapa, etherify i 50-80°C mō te 5 haora, me te pēhanga mōrahi he āhua. Kātahi ka tāpirihia te nui o te waikawa pūhaumāota me te waikawa oxalic ki te wai wera i te 90°C hei whakawhānui ake i te rōrahi. Whakakore wai ki roto i te centrifuge. Ina he iti iho te makuku o te rauemi i te 60%, horoia kia kore e noho, ka whakamaroke ki raro iho i te 5% me te rere o te hau wera ki te 130°C. I te mutunga ka wahia e te tatari 20-mata kia whiwhi ai i te hua kua oti.

Nga waahanga hua o te Hydroxypropyl Methyl Cellulose:

1. He ngawari te wairewa Hydroxypropyl methylcellulose ki te wai matao, ka memeha ki te wai wera. Heoi ano, he tino teitei ake te pāmahana whakahiato i roto i te wai wera i tera o te methylcellulose. Ko te whakakore i roto i te wai matao ka tino pai ake mo te methyl cellulose.

2. Ko te viscosity o te hydroxypropyl methylcellulose e pa ana ki te taumaha ngota, me te nui o te viscosity i te wa e nui ana te taumaha ngota. Ka pa ano te pamahana ki tona pokey, i te pikinga o te pāmahana, ka heke te pokey. Engari he iti ake tona pokey teitei i te methyl cellulose. He pūmau tana otinga i te pāmahana rūma.

Ko te kaha pupuri wai o te hydroxypropyl methylcellulose e whakawhirinaki ana ki te nui o te taapiri, te pokey, me etahi atu, he nui ake te reeti pupuri wai i tera o te methyl cellulose.

3. Ko te Hydroxypropyl methylcellulose he pumau ki te waikawa me te kawakore, a, ka pumau tana wairewa wai i te awhe pH=2-12. He iti te awe o te houra me te wai kotakota ki ona taonga, engari ka taea e te kawakore te whakakoi ake i te rewa me te whakanui paku i tona pokey. Ko te Hydroxypropyl methylcellulose he pumau ki nga tote noa, engari ka nui te kukū o te wairewa tote, ka piki ake te pokey o te otinga hydroxypropyl methylcellulose.

4. Ka taea te whakauru i te Hydroxypropyl methylcellulose ki nga polymers wairewa-wai hei hanga i tetahi otinga rite, teitei-pokey. Pērā i te waipiro polyvinyl, te paura wai roto ether, te kapia huawhenua, etc.

Ko te Hydroxypropyl methylcellulose he pai ake te aukati i te methylcellulose i te methylcellulose, a he iti ake te whakahekenga o te wairewa i te methylcellulose.

5. Ko te whakapiri i waenga i te hydroxypropyl methylcellulose me te hanganga moata he teitei ake i tera o te methylcellulose.

Ko te kumete whakauru makuku he sima, he whakahiato pai, he taapiri me te wai, me nga momo waahanga ka whakatauhia i runga i te mahi. I muri i te ine me te konatunatua ki tetahi tauwehenga i te teihana whakaranu, ka haria te ranunga ki te waahi e whakamahia ana e te taraka whakaranu ka rongoa ki roto i tetahi ipu motuhake, ka whakamahia te ranunga maku i roto i te waa kua tohua.

Me pehea te whakatau i te kounga o te hydroxypropyl methylcellulose?

Ko te whakatau i te kounga o te hydroxypropyl methylcellulose te nuinga ka whakawhirinaki ki nga tohu e rua, ko tetahi ko te tohu whakakapinga (DS) ko tetahi ko te ma. Ko te tikanga, he rereke nga ahuatanga o te carboxymethyl cellulose mena he rereke te tohu whakakapinga; ko te teitei ake o te tohu whakakapinga, ka kaha ake te whakarewatanga, ka pai ake te marama me te pumau o te otinga. E ai ki nga purongo e tika ana, he pai te marama o te carboxymethyl cellulose ina he ~ te tohu whakakapinga, a he tiketike te pokey o tana wairewa wai ina 6-9 te uara pH. Arā, ki te ine i te kounga o te carboxymethyl cellulose, he mea tika kia mohio pai ki tana tohu whakakapinga me te ma. Ko enei tohu e rua ka tutuki nga whakaritenga, ko te tikanga he tino pai tona kounga.