Focus on Cellulose ethers

Te Tikanga Whakaputa Ruku Waiwakore o Hydroxypropyl Methyl Cellulose (HPMC)

Ko te tikanga hanga rumaki kawakore he tikanga noa mo te whakaputa hydroxypropyl methyl cellulose (HPMC). Kei roto i tenei tikanga ko te tauhohenga o te cellulose me te konutai hauwai (NaOH) katahi me te propylene oxide (PO) me te methyl chloride (MC) i raro i etahi tikanga.

Ko te tikanga rumaki kawakore he painga ki te whakaputa HPMC me te taumata teitei o te whakakapinga (DS), e whakatau ana i ona ahuatanga penei i te whakarewatanga, te viscosity, me te reera. Ko te tikanga ko nga waahanga e whai ake nei:

  1. Te Whakaritenga o te Cellulose

Ka riro mai te Cellulose mai i nga puna maori penei i te rakau, te miro, me etahi atu mea tipu. Ka purea te cellulose i te tuatahi katahi ka tukuna ki te NaOH hei hanga i te konutai cellulose, he takawaenga tauhohenga ki te hanga HPMC.

  1. Tauhohenga o te konutai Cellulose me te Propylene Oxide (PO)

Ka tauhohehia te konutai cellulose ki te PO i te aroaro o te whakakorikori penei i te tetramethylammonium hydroxide (TMAH) me te konutai hydroxide (NaOH) i te teitei o te mahana me te pehanga. Ko te tauhohenga ka puta te hanga o te hydroxypropyl cellulose (HPC).

  1. Tauhohenga o te HPC me te Methyl Chloride (MC)

Ka tauhohe te HPC ki te MC i te aroaro o te whakakorikori penei i te konutai waikawa (NaOH) me te waikawa maaota (HCl). Ko te tauhohenga ka puta te hanga o te hydroxypropyl methyl cellulose (HPMC).

  1. Te horoi me te whakamaroke

I muri i te tauhohenga, ka horoia te hua ki te wai ka whakamaroke kia whiwhi HPMC. I te nuinga o te wa ka purea te hua ma te whakamahi i te raupapa filtration me nga hikoi centrifugation hei tango i nga poke.

He maha nga painga o te tikanga rumaki kawakore ki etahi atu tikanga, tae atu ki te DS teitei me te ma, te utu iti, me te ngawari o te tauine. Ka taea hoki te whakamahi i te tikanga ki te whakaputa HPMC me nga ahuatanga rereke ma te rereke i nga tikanga tauhohenga penei i te pāmahana, te pehanga, me te kukū.

Heoi ano, he ngoikoretanga ano te tikanga. Ko te whakamahinga o te NaOH me te MC ka taea te noho haumaru me te noho morearea o te taiao, a, ko te tukanga whakaputa ka pau te wa me te hiahia nui o te kaha.

Hei mutunga, ko te tikanga hanga rumaki kawakore he tikanga e whakamahia nuitia ana mo te whakaputa HPMC. Ko te tikanga ko te tauhohenga o te cellulose me te NaOH, PO, me te MC i raro i etahi tikanga, ka whai i te purenga me te whakamaroke. Ahakoa he ngoikore te tikanga, ko ona painga he mea rongonui mo nga tono ahumahi me te rongoa.


Te wa tuku: Apr-23-2023
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