Focus on Cellulose ethers

Ko nga taonga konutai carboxymethyl cellulose me te whakauru hua

Ko te konutai carboxymethyl cellulose, e kiia ana ko te carboxymethyl cellulose (CMC) ko te ahua o te muka polymer teitei ether kua whakaritea e te whakarereketanga matū o te cellulose taiao. Ko te nuinga o tona hanganga ko te D-glucose wae na roto i te β (1→4) Ka hono tahi nga ki.

Ko te CMC he ma, he miraka ranei, he paura kiko, he kirikiri ranei, he 0.5-0.7 g/cm3 te kiato, tata kore kakara, kore reka, me te hygroscopic. He ngawari te marara ki roto i te wai hei hanga i te otinga colloidal maramara, kare e rewa i roto i nga whakarewa waro penei i te waiwaro. Ko te pH o te 1% wairewa wai ko te 6.5-8.5, i te wa pH>10 ranei <5, ka tino heke te pokey o te mucilage, a ko te mahi he pai rawa ina te pH=7. Ka u ki te wera, ka tere te piki ake o te pokey ki raro i te 20°C, ka huri haere i te 45°C. Ko te whakamahana mo te wa roa i runga ake i te 80°C ka taea te whakakore i te colloid me te tino whakaiti i te pokey me te mahi. He ngawari ki te wairewa i roto i te wai, ka marama te otinga; he tino pumau i roto i te wairewa kawakore, engari ka ngawari te whakamaarama i te wa e pa ana ki te waikawa, a ka heke i te wa e 2-3 te uara pH, ka tauhohe ano ki nga tote whakarewa maha.

Tauira Hanganga: C6H7(OH)2OCH2COONa tātai rāpoi ngota: C8H11O5Na

Ko te tauhohenga matua: ko te cellulose taiao i te tuatahi ka uru ki te tauhohenga kawakore me te NaOH, me te taapiri o te waikawa chloroacetic, ko te hauwai kei runga i te roopu hydroxyl i te wae huka ka uru ki te tauhohenga whakakapi me te roopu carboxymethyl i roto i te waikawa chloroacetic. Ka kitea mai i te tauira hanganga e toru nga roopu hydroxyl i ia wae glucose, ara, C2, C3, and C6 hydroxyl groups. Ko te hauwai kei runga i ia roopu hydroxyl ka whakakapihia e te carboxymethyl, kua tautuhia hei tohu whakakapinga o te 3. Ko te tohu o te whakakapinga o te CMC ka pa tika ki te whakarewatanga, te whakaemulsification, te matotoru, te pumau, te aukati waikawa me te parenga tote oCMC .

I te nuinga o te wa e whakaponohia ana ka tata te tohu o te whakakapinga ki te 0.6-0.7, he pai ake te mahi whakaemulsifying, me te pikinga o te tohu whakakapinga, ka pai ake etahi atu taonga. Ina he nui ake te tohu whakakapinga i te 0.8, ka tino whakanuia tona parenga waikawa me te tote. .

I tua atu, kua whakahuahia ano i runga ake nei e toru nga roopu hydroxyl i ia waahanga, ara, ko nga roopu hydroxyl tuarua o C2 me C3 me te roopu hydroxyl tuatahi o C6. I roto i te ariā, ko te mahi o te roopu hydroxyl tuatahi he nui ake i tera o te roopu hydroxyl tuarua, engari e ai ki te paanga o te isotopic o C, te roopu -OH i runga i te C2 He nui ake te waikawa, ina koa i roto i te taiao o te alkali kaha, tona mahi. he kaha ake i te C3 me te C6, no reira ka kaha ake te whakararu i nga tauhohenga whakakapinga, ka whai ko C6, ko C3 te mea ngoikore.

Ko te tikanga, ko te mahi a te CMC ehara i te mea e pa ana ki te tohu o te whakakapi, engari ano hoki ki te riterite o te tohatoha o nga roopu carboxymethyl i roto i te katoa o te ngota cellulose me te whakakapi o nga roopu hydroxymethyl i ia waahanga me C2, C3, me C6 i roto ia rāpoi ngota. e pā ana ki te ōritetanga. I te mea ko te CMC he puhui raina polymerized, a, ko tana roopu carboxymethyl he whakakapinga taurite i roto i te ngota, he rereke nga tuunga o nga ngota i te wa e tu tonu ana te otinga, a he rereke te roa o te rauropi raina ina he kaha kutikuti i roto i te otinga. . Ko te tuaka he kaha ki te huri ki te ahunga rere, a ka kaha ake tenei ahuatanga i te pikinga o te tere kutikuti kia oti ra ano te whakatakotoranga whakamutunga. Ko tenei ahuatanga o te CMC ka kiia ko te pseudoplasticity. Ko te pseudoplasticity o te CMC he pai ki te homogenization me te kawe paipa, a ka kore e reka ki te hinuhinu rawa i roto i te miraka wai, e pai ana ki te tuku i te kakara miraka. .

Hei whakamahi i nga hua CMC, me tino mohio tatou ki nga tawhā matua penei i te pumau, te viscosity, te waikawa waikawa, me te viscosity. Kia mohio me pehea te whiriwhiri i te hua tika.

Ko nga hua CMC iti-pokey he reka hou, he iti te pokey, me te tata karekau he ahua matotoru. Ka whakamahia te nuinga ki nga ranu motuhake me nga inu. He pai hoki nga wai-waha hauora.

Ka whakamahia te nuinga o nga hua CMC ki roto i nga inu totoka, nga inu pūmua noa me nga wai hua. Me pehea te whiriwhiri ka whakawhirinaki ki nga tikanga whaiaro o nga miihini. I roto i te pumau o nga inu miraka, he nui te takoha a CMC.

Ko nga hua CMC tino-nui he waahi tono ahua nui. Ka whakaritea ki te māngaro, kapia guar, kapia xanthan me etahi atu hua, ka kitea tonu te pumau o te CMC, ina koa ki nga hua kai, ka kitea te painga o te pupuri wai o CMC! I roto i nga whakapumau penei i te aihikirimi, he pai ano te CMC.

Ko nga tohu matua hei ine i te kounga o te CMC ko te tohu whakakapinga (DS) me te ma. Ko te tikanga, he rereke nga ahuatanga o te CMC mena he rereke te DS; ka teitei ake te tohu whakakapinga, ka kaha ake te whakarewatanga, ka pai ake te marama me te pumau o te otinga. E ai ki nga purongo, he pai ake te maarama o te CMC i te wa ko te tohu whakakapinga he 0.7-1.2, ko te pokey o tana wairewa wai te mea nui rawa ina 6-9 te uara pH.

Hei whakarite i tona kounga, i tua atu i te kowhiringa o te kaihoko etherification, me whai whakaaro ano etahi mea e pa ana ki te tohu o te whakakapinga me te ma, penei i te hononga i waenga i te nui o te alkali me te etherification agent, te wa etherification, te ihirangi wai i roto i te pünaha, te mahana, te uara DH, te otinga Te Kohanga me te tote aha atu.

whakataki hua

Ko te kounga o nga hua kua oti te CMC ka whakawhirinaki ki te otinga o te hua. Mena he maamaa te otinga o te hua, he iti noa nga matūriki gel, nga muka kore utu, me nga waahi pango o nga poke, ka tino whakapumautia he pai te kounga o te CMC. Mena ka waiho te otinga mo etahi ra, kaore te otinga e puta. He maama, he koriri ranei, engari he maamaa tonu, he pai ake te hua!


Wā tuku: Tihema-14-2022
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