Super Absorbent Material daga Cellulose Ether

An yi nazarin tsari da aikin samfurin carboxymethyl cellulose giciye ta hanyar N, N-methylenebisacrylamide don shirya resin superabsorbent, da kuma maida hankali na alkali, adadin giciye mai haɗin gwiwa, alkali etherification, da sauran ƙarfi an tattauna. Tasirin sashi akan aikin sha ruwa na samfurin. An yi bayanin hanyar tallatawa na guduro mai shayar da ruwa zuwa ruwa. Nazarin ya nuna cewa ƙimar riƙe ruwa (WRV) na wannan samfurin ya kai 114ml/g.

Mabuɗin kalmomi:ether cellulose; methylenebisacrylamide; shiri

1,Gabatarwa

Superabsorbent resin abu ne na polymer tare da ƙungiyoyi masu ƙarfi na hydrophilic da wani takamaiman matakin haɗin gwiwa. Abubuwan sha na yau da kullun irin su takarda, auduga, da hemp suna da ƙarancin sha ruwa da ƙarancin riƙewar ruwa, yayin da resins masu ɗaukar nauyi na iya ɗaukar ruwa sau da yawa nauyin nasu, kuma gel ɗin da aka kafa bayan shan ruwa ba zai bushe ba ko da tare da dan matsa lamba. Kyakkyawan ƙarfin riƙe ruwa. Ba ya narkewa a cikin ruwa ko a cikin kaushi na halitta.

Akwai adadi mai yawa na ƙungiyoyin hydroxyl, ƙungiyoyin carboxyl da ions sodium hydrate akan sarkar kwayoyin halitta na super absorbent abu da aka yi da cellulose. Bayan shayar da ruwa, ruwan yana kewaye da cibiyar sadarwa na macromolecular hydrophilic kuma ana iya riƙe shi a ƙarƙashin matsa lamba na waje. Lokacin da ruwa ya danƙa resin adsorption, an kafa wani Layer na membrane mai tsaka-tsaki tsakanin guduro da ruwa. Sakamakon yawaitar ions na wayar hannu (Na+) a cikin resin da ke sha ruwa, a cewar Donnan.'s ka'idar ma'auni, wannan bambancin maida hankali na ion zai iya haifar da matsa lamba na osmotic. Poor, forming moistening da kumburi rauni ikon, ruwa ratsa ta cikin wannan Layer na Semi-permeable membrane da hadawa da hydrophilic kungiyoyin da ions a kan macromolecules na superabsorbent guduro, rage taro na wayar hannu ions, game da shi nuna high ruwa sha da kumburi. Wannan tsarin adsorption yana ci gaba har sai bambance-bambancen matsa lamba na osmotic da ke haifar da bambanci a cikin ƙaddamar da ions na wayar hannu daidai yake da juriya ga ci gaba da fadadawa ta hanyar haɗin kai na cibiyar sadarwa ta kwayoyin halitta na resin polymer. Abubuwan da ake amfani da su na resin superabsorbent da aka shirya daga cellulose sune: matsakaicin matsakaicin ruwa na ruwa, saurin shayar ruwa mai sauri, ruwan gishiri mai kyau, maras guba, mai sauƙi don daidaita darajar pH, za a iya lalata shi a yanayi, da ƙananan farashi, don haka yana da fadi. kewayon amfani. Ana iya amfani da shi azaman wakili mai toshe ruwa, kwandishan ƙasa, da wakili mai riƙe ruwa a masana'antu da noma. Bugu da ƙari, yana da kyakkyawan ci gaba da kuma buƙatun aikace-aikace a cikin lafiya, abinci, ƙwayoyin cuta, da magani.

2. Sashin gwaji

2.1 Ƙa'idar gwaji

Shirye-shiryen fiber na auduga superabsorbent resin shine galibi don samar da tsarin haɗin giciye tare da ƙaramin digiri na musanyawa akan fatar fiber. Haɗin kai zuwa mahadi waɗanda gabaɗaya suna da ƙungiyoyin aiki guda biyu ko fiye. Ƙungiyoyi masu aiki waɗanda ke iya haɗawa da haɗin gwiwa sun haɗa da vinyl, hydroxyl, carboxyl, amide, acid chloride, oxirane, nitrile, da dai sauransu. Ruwan sha na ruwa na resins superabsorbent wanda aka shirya tare da ma'auni daban-daban na haɗin giciye ya bambanta. A cikin wannan gwaji, ana amfani da N, N-methylenebisacrylamide azaman wakili mai haɗin kai, gami da matakai masu zuwa:

(1) Cellulose (Rcell) yana amsawa tare da bayani na alkaline don samar da alkali cellulose, kuma alkalization dauki na cellulose ne m exothermic dauki. Rage yawan zafin jiki yana da tasiri ga samuwar alkali zaruruwa kuma zai iya hana su hydrolysis. Ƙara barasa zai iya ƙara rashin lafiyar cellulose, wanda ke da amfani ga alkalization da etherification na gaba.

RcellOH+NaOH→RcellONa+H2O

(2) Alkali cellulose da monochloroacetic acid suna haifar da sodium carboxymethyl cellulose, kuma amsawar etherification na cikin yanayin maye gurbin nucleophilic:

RcellONa+ClCH2COONa→RcellOCH2COONa+NaCl

(3) N, N-methylenebisacrylamide haɗe-haɗe don samun babban guduro mai sha. Domin har yanzu akwai babban adadin hydroxyl kungiyoyin a kan kwayoyin sarkar na carboxymethyl fiber, da ionization na hydroxyl kungiyar cellulose da ionization na acryloyl biyu bond a kan kwayoyin sarkar na N, N-methylenebisacrylamide za a iya jawo a karkashin mataki. na alkali catalysis, sa'an nan Cross-linking tsakanin cellulose kwayoyin sarkar faruwa ta hanyar Michael condensation, kuma nan da nan sha proton musayar da ruwa ya zama ruwa-insoluble cellulose superabsorbent guduro.

2.2 Raw kayan da kayan aiki

Raw kayan: absorbent auduga (yanke cikin linters), sodium hydroxide, monochloroacetic acid, N, N-methylenebisacrylamide, cikakken ethanol, acetone.

Kayan aiki: Flask mai wuya uku, motsawar wutar lantarki, reflux condenser, tsotsa flask, Buchner mazurari, injin bushewa tanda, zazzage injin injin famfo.

2.3 Hanyar shiri

2.3.1 Alkalinization

Ƙara 1 g na auduga mai shayarwa a cikin kwalban wuyansa uku, sa'an nan kuma ƙara wani adadin adadin sodium hydroxide da cikakken ethanol, kiyaye zafin jiki a ƙasa da zafin jiki, da motsawa na ɗan lokaci.

2.3.2 Etherification

Ƙara wani adadin chloroacetic acid kuma motsawa na 1h.

2.3.2 Haɗin kai

A cikin mataki na gaba na etherification, an ƙara N, N-methylenebisacrylamide a cikin rabo don aiwatar da haɗin kai, kuma an motsa shi a dakin da zafin jiki na 2 hours.

2.3.4 Bayan aiwatarwa

Yi amfani da glacial acetic acid don daidaita ƙimar pH zuwa 7, wanke gishiri da ethanol, wanke ruwa tare da acetone, tace tare da tsotsa, da bushewa na tsawon sa'o'i 4 (kimanin 60).°C, digiri 8.8kPa) don samun samfurin filament na farin auduga.

2.4 Gwajin nazari

Ana ƙayyade adadin sha ruwa (WRV) ta hanyar sieving, wato, 1g na samfurin (G) ana ƙara shi a cikin baƙar fata mai ɗauke da 100ml na ruwa mai tsafta (V1), an jiƙa na tsawon sa'o'i 24, ana tacewa ta hanyar allon bakin karfe mai lamba 200. , kuma ana tattara ruwan da ke ƙasan allon (V2). Tsarin lissafin shine kamar haka: WRV=(V1-V2)/G.

3. Sakamako da tattaunawa

3.1 Zaɓin yanayin halayen alkalization

A cikin aiwatar da samar da alkali cellulose ta hanyar aikin fiber auduga da maganin alkaline, yanayin tsari yana da tasiri mai mahimmanci akan aikin samfurin. Akwai dalilai da yawa a cikin halayen alkalization. Don dacewar lura, ana ɗaukar hanyar ƙirar gwaji ta orthogonal.

Sauran yanayi: The ƙarfi ne 20ml na cikakkar ethanol, da rabo daga alkali zuwa etherifying wakili (mol/md) ne 3: 1, da crosslinking wakili ne 0.05g.

Sakamakon gwaji ya nuna cewa: dangantaka ta farko da ta biyu: C> A> B, mafi kyawun rabo: A3B3C3. Matsakaicin lye shine mafi mahimmancin abu a cikin halayen alkalization. Babban taro na lye yana taimakawa wajen samar da alkali cellulose. Duk da haka, ya kamata a lura da cewa mafi girma maida hankali na lye, mafi girma da gishiri abun ciki na shirye superabsorbent guduro. Sabili da haka, lokacin wanke gishiri tare da ethanol, wanke shi sau da yawa don tabbatar da cewa an cire gishirin da ke cikin samfurin, don kada ya shafi ƙarfin shayar da ruwa na samfurin.

3.2 Tasirin sashi na wakili na crosslinking akan samfur WRV

Sharuɗɗan gwaji sune: 20ml na cikakken ethanol, 2.3: 1 rabo na alkali zuwa wakili na etherification, 20ml na lye, da 90min alkalization.

Sakamakon ya nuna cewa adadin ma'auni na haɗin gwiwar ya shafi digiri na haɗin gwiwar CMC-Na. Ƙimar giciye mai yawa yana haifar da tsarin cibiyar sadarwa mai tsauri a cikin sararin samfurin, wanda ke da ƙananan ƙarancin ruwa da rashin ƙarfi mara kyau bayan shayar ruwa; lokacin da adadin ma'aunin haɗin gwiwar ya yi ƙanƙanta, haɗin giciye bai cika ba, kuma akwai samfurori masu narkewa da ruwa, wanda kuma ya shafi yawan sha ruwa. Lokacin da adadin ma'aunin haɗin ketare ya kasa da 0.06g, yawan shayarwar ruwa yana ƙaruwa tare da karuwar yawan adadin ma'auni, lokacin da adadin abin da ya fi girma fiye da 0.06g, yawan sha ruwa ya ragu. tare da adadin ma'auni mai haɗawa. Saboda haka, sashi na wakilin crosslinking shine kusan 6% na yawan fiber na auduga.

3.3 Tasirin yanayin etherification akan samfur WRV

Yanayin gwaji sune: alkali maida hankali 40%; alkali girma 20 ml; cikakken ethanol 20 ml; ma'aunin ma'aunin haɗin giciye 0.06g; alkalization 90min.

Daga nau'in halayen sinadaran, rabon alkali-ether (NaOH: CICH2-COOH) ya kamata ya zama 2: 1, amma ainihin adadin alkali da aka yi amfani da shi ya fi wannan rabo, saboda wani adadin alkali kyauta dole ne a tabbatar da shi a cikin tsarin amsawa. , saboda: wasu Maɗaukaki mafi girma na tushen kyauta yana taimakawa wajen kammala aikin alkalization; dole ne a aiwatar da halayen haɗin kai a ƙarƙashin yanayin alkaline; wasu halayen gefe suna cinye alkali. Duk da haka, idan an ƙara adadin alkali da yawa, fiber alkali zai ragu sosai, kuma a lokaci guda, za a rage tasirin etherification. Gwaje-gwaje sun nuna cewa rabon alkali zuwa ether shine kusan 2.5: 1.

3.4 Tasirin adadin ƙarfi

Yanayin gwaji sune: alkali maida hankali 40%; alkali sashi 20 ml; alkali-ether rabo 2.5: 1; Matsakaicin wakili mai haɗin kai 0.06g, alkalization 90min.

The sauran ƙarfi anhydrous ethanol taka rawa da dispersing, homogenizing da kuma rike da slurry jihar na tsarin, wanda yake da amfani ga tarwatsa da kuma canja wurin zafi saki a lokacin samuwar alkali cellulose, kuma zai iya rage hydrolysis dauki alkali cellulose, game da shi samun uniform. cellulose . Duk da haka, idan adadin barasa ya yi yawa, alkali da sodium monochloroacetate za su narke a cikinsa, ƙaddamar da masu amsawa zai ragu, ƙimar amsawa zai ragu, kuma zai haifar da mummunar tasiri a kan haɗin gwiwa na gaba. Lokacin da adadin cikakken ethanol shine 20ml, ƙimar WRV tana da girma.

A taƙaice, mafi dacewa yanayi don shirya superabsorbent guduro daga absorbent auduga alkalized da etherified carboxymethyl cellulose giciye-da alaka da N, N-methylenebisacrylamide ne: alkali maida hankali 40%, sauran ƙarfi-free 20ml na ruwa da ethanol, da rabo daga alkali zuwa ether. shine 2.5: 1, kuma sashi na wakilin crosslinking shine 0.06g (6% na adadin adadin auduga).