Focus on Cellulose ethers

Me pehea te hanga Cellulose ether?

Me pehea te hanga Cellulose ether?

Ether Cellulose he ahua o te pärönaki cellulose e whiwhi ana i te whakaeterera whakarerekëtanga o te cellulose.Kei te whakamahia nuitia na te mea he tino pai te matotoru, te whakaemulsification, te aukati, te hanga kiriata, te colloid tiaki, te pupuri makuku, me nga taonga taapiri.Ka whai waahi nui ki te whakawhanaketanga o te ohanga o te motu i roto i nga rangahau pūtaiao me nga waahanga ahumahi penei i te kai, te rongoa, te hanga pepa, te paninga, nga taonga hanga whare, te whakaora hinu, nga kakano me nga waahanga hiko.I roto i tenei pepa, ka arotakehia te ahunga whakamua rangahau mo te whakarereketanga whakaeera o te cellulose.

CelluloseetereKo te polymer waro tino nui i roto i te taiao.He mea whakahou, he kakariki me te biocompatible.He rauemi mata nui mo te mahi matū.E ai ki nga rereke rereke i runga i te ngota i puta mai i te tauhohenga etherification, ka taea te wehea ki nga ethers kotahi me te whakauru. pūtau etere.Tenei matou ka arotake i te ahunga whakamua rangahau mo te whakahiatotanga o nga etero kotahi, tae atu ki nga etero alkyl, etero hydroxyalkyl, etera carboxyalkyl, me nga etera whakauru.

kupu matua: pūtau etere, etherification, ether kotahi, ether ranunga, te ahunga whakamua rangahau

 

1.Etherification tauhohenga o te cellulose

 

Ko te tauhohenga etherification o te cellulose etere ko te tauhohenga whakawhanaungatanga o te cellulose tino nui.Ko te whakahiatotanga o te cellulose he raupapa pärönaki i puta mai i te tauhohenga o nga roopu hydroxyl i runga i nga mekameka ngota ngota cellulose me nga kaihoko alkylating i raro i nga tikanga kawakore.He maha nga momo hua o te cellulose ether, ka taea te wehewehe ki nga ethers kotahi me nga ethers whakauru i runga i nga rereke rereke i runga i nga ngota i puta mai i te tauhohenga etherification.Ka taea te wehewehea nga etero kotahi ki nga etero alkyl, nga etero hydroxyalkyl me nga etero carboxyalkyl, a ko nga etera whakauru e tohu ana ki nga eter e rua, neke atu ranei nga roopu e hono ana i te hanganga ngota.I roto i nga hua cellulose ether, carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) e tohuhia ana, kei roto etahi o enei hua kua hokohoko.

 

2.Synthesis o te cellulose ether

 

2.1 Te whakahiato o te ether kotahi

Ko nga ethers kotahi ko nga alkyl ethers (pēnei i te ethyl cellulose, propyl cellulose, phenyl cellulose, cyanoethyl cellulose, me etahi atu), hydroxyalkyl ethers (pēnei i te hydroxymethyl cellulose, hydroxyethyl cellulose, me etahi atu), carboxyalkyl ethers (pērā i te carboxymethylyecellulose, cellulose carboxymethylye. etc.).

2.1.1 Te whakahiato o te alkyl ethers

Ko Berglund et al i tukinotia tuatahitia te cellulose ki te wairewa NaOH i tapirihia ki te ethyl chloride, katahi ka tapirihia te methyl chloride i te mahana o te 65°C ki te 90°C me te pehanga 3bar ki te 15bar, ka tauhohe ki te whakaputa methyl cellulose ether.Ka taea e tenei tikanga te tino pai Ki te whiwhi wai-wairewa methyl cellulose ethers me nga nekehanga rereke o te whakakapi.

Ko te Ethylcellulose he kowhatu werawera ma, he paura ranei.Ko nga taonga whanui kei roto 44% ~ 49% ethoxy.Wairewa i roto i te nuinga o nga whakarewa pararopi, karekau ki te wai.te penupenu me te miro linters ki te 40% ~ 50% konutai waihā wairewa wai, me te cellulose alkalized i ethoxylated ki ethyl pūhaumāota ki te whakaputa ethyl cellulose.i pai te whakahiato i te ethyl cellulose (EC) me te ihirangi ethoxy o te 43.98% na roto i te tikanga kotahi-taahiraa ma te tauhohe i te cellulose me te ethyl chloride me te konutai hydroxide, ma te whakamahi i te toluene hei waimeha.I whakamahia te Toluene hei diluent i roto i te whakamatautau.I roto i te tauhohenga etherification, e kore e taea anake te whakatairanga i te titorehanga o te ethyl chloride ki te cellulose alkali, engari ano te whakakore i te tino whakakapi ethyl cellulose.I te wa o te tauhohenga, ka taea te whakaatu tonu i te waahanga kaore i arohia, ka hanga i te kaihoko etherification He ngawari ki te whakaeke, kia huri te tauhohenga ethylation mai i te heterogeneous ki te homogeneous, me te tohatoha o nga whakakapi i roto i te hua ka nui ake te rite.

i whakamahia te ethyl bromide hei kaihoko whakaetere me te tetrahydrofuran hei waimeha ki te whakahiato i te ethyl cellulose (EC), me te tohu i te hanganga hua na roto i te spectroscopy infrared, te resonance autō karihi me te chromatography permeation gel.Ka tatauhia ko te tohu whakakapinga o te ethyl cellulose he 2.5, he whaiti te tohatoha papatipu ngota, a he pai te whakarewatanga i roto i nga whakarewa waro.

cyanoethyl cellulose (CEC) na roto i nga tikanga homogeneous me te heterogeneous ma te whakamahi i te cellulose me nga nekehanga rereke o te polymerization hei rauemi mata, me te whakarite i nga rauemi kiriuhi CEC kiato ma te whakarewanga otinga me te pehi wera.I whakaritea nga kiriuhi CEC porou e te hangarau whakawehenga wahanga whakarewa (NIPS), me te barium titanate/cyanoethyl cellulose (BT/CEC) nanocomposite membrane i whakaritea e te hangarau NIPS, a, i akohia o raatau hanganga me o raatau taonga.

whakamahia te whakarewa cellulose whaiaro-whakawhanakehia (wairewa wairewa / Urea) rite te reo tauhohenga ki homogeneously synthesize cyanoethyl cellulose (CEC) ki acrylonitrile rite te kaihoko etherification, me te whakahaere rangahau i runga i te hanganga, āhuatanga me te tono o te hua.te ako hohonu.A, ma te whakahaere i nga ahuatanga tauhohenga rereke, ka taea te whiwhi i te raupapa o nga CEC me nga uara DS mai i te 0.26 ki te 1.81.

2.1.2 Te whakahiatotanga o nga etera hydroxyalkyl

I whakaritea e Fan Junlin et al te hydroxyethyl cellulose (HEC) i roto i te reactor 500 L ma te whakamahi i te miro para hei rauemi mata me te 87.7% isopropanol-wai hei whakarewa ma te kotahi-step alkalization, taahiraa-i-step neutralization me te taahiraa-i-step etherification..I kitea e nga hua ko te hydroxyethyl cellulose (HEC) kua rite he MS whakakapinga molar mo te 2.2-2.9, ka eke ki te paerewa kounga rite ki te hua hokohoko Dows 250 HEC me te whakakapi molar o 2.2-2.4.Ma te whakamahi i te HEC ki te hanga peita taherapa ka taea te whakapai ake i nga ahuatanga hanga kiriata me te whakataurite o te peita taherapa.

I korero a Liu Dan me etahi atu mo te whakarite o te haukinia haukinia tote cationic hydroxyethyl cellulose ma te tikanga ahua maroke o te hydroxyethyl cellulose (HEC) me te 2,3-epoxypropyltrimethylammonium chloride (GTA) i raro i te mahi o te catalysis alkali.tikanga ether.I tirotirohia te paanga o te taapiri i te cationic hydroxyethyl cellulose ether ki runga pepa.Ko nga hua o te whakamatautau e whakaatu ana: i roto i te penupenu rakau kua whakapoipoihia, ina ko te tohu whakakapinga o te cationic hydroxyethyl cellulose ether he 0.26, ka piki te tapeke o te reeti pupuri ma te 9%, ka piki te reeti filtration wai ma te 14%;i roto i te penupenu rakau maro, ina ko te nui o te cationic hydroxyethyl cellulose ether he 0.08% o te muka penupenu, he tino kaha te whakakaha ki te pepa;ka nui ake te tohu whakakapinga o te etera cellulose cationic, ka nui ake te kiato utu cationic, me te pai ake o te kaha whakakaha.

Ka whakamahi a Zhanhong i te tikanga whakahiato wai-waahanga ki te whakarite i te hydroxyethyl cellulose me te uara viscosity o te 5×104mPa·s neke atu ranei me te uara pungarehu iti iho i te 0.3% na roto i te tukanga e rua-taahiraa o te whakamaaramatanga me te whakamaarama.E rua nga tikanga whakamaarama i whakamahia.Ko te tikanga tuatahi ko te whakamahi i te acetone hei waimeha.Ko te rauemi mata o te cellulose he mea hanga tika ki tetahi kukū o te konutai waiwai wairewa wai.I muri i te whakahaerenga o te tauhohenga whakamaaramatanga, ka taapirihia he kaihoko whakamaarama ki te kawe tika i te tauhohenga etherification.Ko te tikanga tuarua ko te kawakore o te cellulose raw rauemi i roto i te wairewa wai o te konutai waiwaro me te Urea, a ko te cellulose kawakore kua oti te whakarite ma tenei tikanga me ruia ki te tango i te rei i mua i te tauhohenga etherification.Ko nga hua whakamatautau e whakaatu ana ko nga mea penei i te nui o te waimeha kua tohua, te nui o te ethylene oxide i tapirihia, te wa whakamaaramatanga, te pāmahana me te wa o te tauhohenga tuatahi, me te pāmahana me te wa o te tauhohenga tuarua ka whai mana nui ki te mahi. o te hua.

Xu Qin et al.i whakahaeretia te tauhohenga whakaetere o te cellulose alkali me te propylene oxide, me te whakahiato hydroxypropyl cellulose (HPC) me te tohu whakakapinga iti ma te tikanga wahanga hau-totoka.I akohia nga paanga o te hautanga papatipu o te propylene oxide, te ōwehenga kuiti me te pāmahana whakaetherification i runga i te tohu o te etherification o te HPC me te whakamahi whaihua o te propylene oxide.I kitea e nga hua ko nga tikanga whakahiato tino pai o te HPC ko te hautanga papatipu propylene oxide 20% (te ōwehenga papatipu ki te cellulose), te ōwehenga tangohanga cellulose alkali 3.0, me te pāmahana whakaetherification 60°C. Ko te whakamatautau hanganga o te HPC ma te resonance autō karihi e whakaatu ana ko te tohu o te etherification o te HPC ko te 0.23, ko te tere whakamahi whai hua o te propylene oxide ko te 41.51%, me te hono pai o te mekameka ngota cellulose ki nga roopu hydroxypropyl.

Kong Xingjie et al.kua rite te hydroxypropyl cellulose ki te wai katote hei whakarewa ki te mohio i te tauhohenga o te cellulose kia mohio ai ki te whakaritenga o te tukanga tauhohenga me nga hua.I te wa o te whakamatautau, i whakamahia te wai katote imidazole phosphate phosphate synthetic 1, 3-diethylimidazole diethyl phosphate ki te whakakore i te microcrystalline cellulose, a ka whiwhihia te hydroxypropyl cellulose na roto i te whakamaaramatanga, te etherification, te waikawa, me te horoi.

2.1.3 Te whakahiato o te carboxyalkyl ethers

Ko te carboxymethyl cellulose he carboxymethyl cellulose (CMC).Ko te otinga wai o te carboxymethyl cellulose nga mahi o te whakapakeke, te hanga kiriata, te honohono, te pupuri wai, te whakamarumaru colloid, te emulsification me te whakatārewatanga, ka whakamahia nuitia ki te horoi.Te rongoa, te kai, te toothpaste, te kakano, te ta me te tae, te hanga pepa, te hinu, te maina, te rongoa, te karamu, nga waahanga hiko, te rapa, te peita, te pesticides, te whakapaipai, te hiako, te kirihou me te keri hinu, aha atu.

I te tau 1918, na Tiamana E. Jansen te tikanga whakahiato o te carboxymethyl cellulose.I te 1940, ko te wheketere Kalle o te Kamupene IG Farbeninaustrie Tiamana i mohio ki nga mahi ahumahi.I te tau 1947, ko te Wyandotle Chemical Company o te United States i angitu te whakawhanake i tetahi tukanga whakaputa tonu.Ko taku whenua i uru tuatahi ki roto i nga mahi ahumahi CMC i Shanghai Celluloid Factory i te tau 1958. Ko te Carboxymethyl cellulose he etera cellulose i puta mai i te miro parakore i raro i te mahi a te konutai waikawa me te waikawa chloroacetic.Ka taea te wehea ona tikanga whakaputa ahumahi ki nga waahanga e rua: te tikanga wai-a-wai me te tikanga whakarewa-whakarewa kia rite ki nga momo rereke rereke.Ko te tukanga e whakamahi ana i te wai hei reo tauhohenga ka kiia ko te tikanga wai, a, ko te tukanga kei roto he whakarewa waro i roto i te reo tauhohenga ka kiia ko te tikanga whakarewa.

Na te whakahohonutanga o te rangahau me te ahu whakamua o te hangarau, kua whakamahia nga tikanga tauhohenga hou ki te whakahiato o te carboxymethyl cellulose, a he nui te paanga o te punaha whakarewa hou ki te tukanga tauhohenga, te kounga hua ranei.Olaru et al.i kitea he pai ake te tauhohenga carboxymethylation o te cellulose e whakamahi ana i te punaha whakangao ewaro-acetone i tera o te ewaro me te acetone anake.Nicholson et al.I roto i te punaha, i whakaritea te CMC me te iti o te whakakapinga.I whakaritea e Philipp et al te CMC tino whakakapi me te N-methylmorpholine-N oxide me N, N dimethylacetamide/lithium chloride pūnaha whakarewa.Kai et al.i whakawhanakehia he tikanga mo te whakarite CMC i roto i te punaha whakarewa NaOH/urea.Ramos et al.whakamahia te DMSO/tetrabutylammonium fluoride katote pūnaha wai hei whakarewa ki te carboxymethylate te cellulose raw rauemi parakore i te miro me te sisal, a ka whiwhi i te hua CMC ki te tohu whakakapinga rite tiketike ki te 2.17.Chen Jinghuan et al.whakamahia te cellulose ki te kukū penupenu tiketike (20%) rite rauemi mata, konutai waihā me te acrylamide rite tauhohenga whakarerekētanga, kawea i roto i te tauhohenga whakarerekētanga carboxyethylation i te wa whakaritea, me te pāmahana, a ka te mutunga whiwhi carboxyethyl base cellulose.Ko te ihirangi carboxyethyl o te hua kua whakarereketia ka taea te whakahaere ma te whakarereke i te nui o te konutai hydroxide me te acrylamide.

2.2 Te whakahiatotanga o nga etera whakauru

Ko te Hydroxypropyl methyl cellulose ether he ahua o te etera cellulose kore-polar ka whakarewahia i roto i te wai matao i riro mai i te cellulose taiao ma te whakarereketanga me te whakarereketanga.Ka kawakawahia ki te wairewa konutai konutai me te taapiri i te nui o te nui o te isopropanol me te toluene whakarewa, ko te kaihoko etherification e tango ana ko te methyl chloride me te propylene oxide.

Dai Mingyun et al.I whakamahia te hydroxyethyl cellulose (HEC) hei tuara o te polymer hydrophilic, ka honoa te kaihoko hydrophobizing butyl glycidyl ether (BGE) ki runga i te tuara ma te tauhohenga etherification hei whakatika i te roopu butyl roopu hydrophobic.Ko te tohu o te whakakapinga o te roopu, kia whai uara taurite hydrophilic-lipophilic e tika ana, me te 2-hydroxy-3-butoxypropyl hydroxyethyl cellulose (HBPEC) whakautu ki te pāmahana;kua whakaritea he rawa-a-mahana Ko nga rauemi mahi a te cellulose he huarahi hou mo te whakamahi i nga rawa mahi i roto i nga mara o te tukunga rongoa me te koiora.

I whakamahia e Chen Yangming me etahi atu te hydroxyethyl cellulose hei rauemi mata, a, i roto i te punaha otinga isopropanol, ka tapirihia he iti o te Na2B4O7 ki te reactant mo te tauhohenga rite ki te whakarite i te ether hydroxyethyl carboxymethyl cellulose.Ko te hua kei roto tonu i te wai, a Ko te pokey he pumau.

Ka whakamahi a Wang Peng i te miro kua parahia te cellulose hei rauemi mata, me te whakamahi i te tukanga etherification kotahi-taahiraa ki te whakaputa i te carboxymethyl hydroxypropyl cellulose me te tauhohenga rite, te pokey teitei, te pai o te waikawa waikawa me te tote na roto i te whakamaaramatanga me nga tauhohenga etherification.Ma te whakamahi i te tukanga etherification kotahi-taahiraa, ko te carboxymethyl hydroxypropyl cellulose i hangaia he pai te tote, te aukati waikawa me te wairewa.Ma te whakarereke i te nui o te propylene oxide me te waikawa chloroacetic, ka taea te whakarite i nga hua me nga momo momo carboxymethyl me te hydroxypropyl.Ko nga hua whakamatautau e whakaatu ana ko te carboxymethyl hydroxypropyl cellulose i hangaia e te tikanga kotahi-taahiraa he huringa whakaputa poto, he iti te kai whakarewa, a he pai te aukati o te hua ki nga tote monovalent me te divalent me te pai o te waikawa waikawa.Ka whakatauritea ki etahi atu hua cellulose ether, he kaha ake te whakataetae i roto i nga mara o te kai me te tirotiro hinu.

Ko te Hydroxypropylmethylcellulose (HPMC) te momo tino whaihua me te tino mahi i roto i nga momo cellulose katoa, a he tohu ano hoki mo te hokohoko i waenga i nga etera whakauru.I te tau 1927, i pai te whakahiato me te wehe i te hydroxypropylmethylcellulose (HPMC).I te tau 1938, i mohio a Dow Chemical Co. o te United States ki te hanga ahumahi o te methyl cellulose me te hanga i te tohu rongonui rongonui "Methocel".Ko te hanga ahumahi nui-nui o te hydroxypropyl methylcellulose i timata i te United States i te 1948. Ko te tukanga whakaputa o te HPMC ka taea te wehewehe ki nga waahanga e rua: te tikanga wahanga hau me te tikanga wahanga wai.I tenei wa, ko nga whenua whakawhanake penei i a Uropi, Amerika me Japan kei te kaha ake te tango i te waahanga hau, a ko te hanga kaainga o te HPMC te nuinga i runga i te waahanga wai.

Ko Zhang Shuangjian me etahi atu i whakakore i te paura miro hei rauemi mata, ka whakamaaramatia ki te konutai waikawa i roto i te tauhohenga whakarewa reo toluene me te isopropanol, i whakakorikorihia ki te propylene oxide me te methyl chloride, ka tauhohe me te whakarite i te ahua o te hydroxypropyl methyl alcohol base cellulose ether.

 

3. Tirohanga

Ko te Cellulose he matū matū nui me te matū rawa e whai rawa ana i nga rauemi, he kaakaariki me te taiao, me te whakahou.Ko nga hua o te whakarereketanga o te cellulose etherification he tino pai te mahi, te whanuitanga o nga whakamahinga me nga painga whakamahi pai, me te whakatutuki i nga hiahia o te ohanga o te motu ki te nui.A ko nga hiahia o te whakawhanaketanga hapori, me te ahunga whakamua hangarau tonu me te whakatutukitanga o te hokohoko i nga wa kei te heke mai, mena ka taea e nga rauemi mata waihanga me nga tikanga waihanga o te cellulose derivatives kia nui ake te ahumahi, ka kaha ake te whakamahi me te mohio ki te whānuitanga o nga tono. Uara.

 

 


Te wa tuku: Hanuere-06-2023
WhatsApp Chat Online!