Nonionic cellulose ether mu simenti ya polima

Monga chowonjezera chofunikira mu simenti ya polima, nonionic cellulose ether yalandira chidwi komanso kafukufuku wambiri. Kutengera ndi mabuku oyenera kunyumba ndi kunja, lamulo ndi limagwirira osakhala ionic mapadi etere kusinthidwa simenti matope anakambidwa ku mbali za mitundu ndi kusankha sanali ionic mapadi efa, zotsatira zake pa katundu thupi la polima simenti, zotsatira zake pa micromorphology ndi katundu makina, ndi zofooka za kafukufuku panopa anaika patsogolo. Ntchitoyi idzalimbikitsa kugwiritsa ntchito cellulose ether mu simenti ya polima.

Mawu ofunikira: nonionic cellulose ether, simenti ya polima, katundu wakuthupi, makina amakina, microstructure

1. Mwachidule

Ndi kuchuluka kwa kufunikira ndi zofunikira za ntchito ya simenti ya polima pantchito yomanga, kuwonjezera zowonjezera pakusintha kwake kwakhala malo opangira kafukufuku, pakati pawo, ether ya cellulose yakhala ikugwiritsidwa ntchito kwambiri chifukwa champhamvu yake pakusunga madzi amatope a simenti, kukhuthala, kuchedwa, mpweya. ndi zina zotero. Mu pepala ili, mitundu ya mapadi etere, zotsatira za thupi ndi makina katundu wa polima simenti ndi micromorphology wa polima simenti akufotokozedwa, amene amapereka buku lofotokoza za ntchito mapadi etere mu polima simenti.

2. Mitundu ya nonionic cellulose ether

Ma cellulose ether ndi mtundu wa polima wopangidwa ndi ether opangidwa kuchokera ku cellulose. Pali mitundu yambiri ya cellulose ether, yomwe imakhudza kwambiri zinthu za simenti ndipo ndizovuta kusankha. Malinga ndi kapangidwe kake kazinthu zolowa m'malo, amatha kugawidwa kukhala ma ether anionic, cationic ndi nonionic. Nonionic cellulose ether yokhala ndi mbali ya H, cH3, c2H5, (cH2cH20)nH, [cH2cH(cH3)0]nH ndi magulu ena osagawanika ndi omwe amagwiritsidwa ntchito kwambiri mu simenti, oimira ena ndi methyl cellulose ether, hydroxypropyl methyl. cellulose ether, hydroxyethyl methyl cellulose ether, hydroxyethyl cellulose ether ndi zina zotero. Mitundu yosiyanasiyana ya ma cellulose ether imakhala ndi zotsatira zosiyana pa nthawi yoyika simenti. Malinga ndi malipoti am'mbuyomu, HEC ili ndi mphamvu yochepetsetsa kwambiri ya simenti, yotsatiridwa ndi HPMc ndi HEMc, ndipo Mc ali ndi zoyipa kwambiri. Kwa mtundu womwewo wa cellulose ether, kulemera kwa maselo kapena mamasukidwe akayendedwe, methyl, hydroxyethyl, hydroxypropyl zomwe zili m'maguluwa ndizosiyana, kubweza kwake kumakhalanso kosiyana. Nthawi zambiri, kukhuthala kwakukuru komanso kuchuluka kwamagulu osagwirizana, kumapangitsanso kuthekera kochedwa. Choncho, mu ndondomeko yeniyeni yopangira, malinga ndi zofunikira za coagulation ya matope amalonda, gulu loyenera logwira ntchito la cellulose ether likhoza kusankhidwa. Kapena popanga ma cellulose ether panthawi imodzimodziyo, sinthani zomwe zili m'magulu ogwira ntchito, kuti zigwirizane ndi zofunikira za matope osiyanasiyana.

3,mphamvu ya nonionic cellulose ether pa zinthu zakuthupi za simenti ya polima

3.1 Slow coagulation

Kutalikitsa hydration kuumitsa nthawi ya simenti, kuti matope atsopano osakanikirana mu nthawi yaitali kukhala pulasitiki, kuti asinthe atakhala nthawi ya matope atsopano osakaniza, kusintha operability ake, kawirikawiri kuwonjezera retarder mu matope, sanali- ionic cellulose ether ndi oyenera polima simenti ndi retarder wamba.

The retarding zotsatira za nonionic mapadi efa pa simenti makamaka anakhudzidwa ndi mtundu wake, mamasukidwe akayendedwe, mlingo, zikuchokera osiyana mchere simenti ndi zinthu zina. Pourchez J et al. anasonyeza kuti apamwamba mlingo wa mapadi etere methylation, woipa kwambiri zotsatira retarding, pamene maselo kulemera kwa mapadi efa ndi hydroxypropoxy okhutira anali ndi zotsatira ofooka pa retarding simenti hydration. Ndi kuwonjezeka kwa mamasukidwe akayendedwe ndi doping kuchuluka sanali ionic mapadi efa, ndi adsorption wosanjikiza pamwamba pa particles simenti unakhuthala, ndi koyambirira ndi komaliza kukhazikitsa nthawi simenti anawonjezera, ndipo zotsatira retarding ndi zoonekeratu. Kafukufuku wasonyeza kuti kutentha koyambirira kwa slurries ya simenti ndi zinthu zosiyanasiyana za HEMC ndi pafupifupi 15% yotsika kuposa ya simenti yoyera, koma palibe kusiyana kwakukulu mu ndondomeko ya hydration pambuyo pake. Singh NK ndi al. adawonetsa kuti pakuwonjezeka kwa kuchuluka kwa HEc doping, kutulutsa kwa kutentha kwa hydration kwa matope a simenti osinthidwa kunawonetsa chizolowezi choyambira ndikuchepera, ndipo zomwe zili mu HEC zikafika pakutulutsa kutentha kwa hydration zinali zokhudzana ndi zaka zakuchiritsa.

Kuphatikiza apo, zikuwoneka kuti kubweza kwa nonionic cellulose ether kumagwirizana kwambiri ndi kapangidwe ka simenti. Peschard et al. adapeza kuti kutsika kwa tricalcium aluminate (C3A) mu simenti, m'pamenenso kumachepetsa kuchepa kwa cellulose ether. schmitz L ndi al. ankakhulupirira kuti izi zinayambitsidwa ndi njira zosiyanasiyana za cellulose ether ku hydration kinetics ya tricalcium silicate (C3S) ndi tricalcium aluminate (C3A). Ma cellulose ether amatha kuchepetsa momwe amachitira mu nthawi yofulumira ya C3S, pomwe C3A imatha kutalikitsa nthawi yophunzitsira, ndipo pomaliza pake kuchedwetsa kulimba ndi kuuma kwa matope.

Pali malingaliro osiyanasiyana pamakina a non-ionic cellulose ether akuchedwetsa simenti hydration. Silva et al. Liu ankakhulupirira kuti kuyambika kwa cellulose ether kungapangitse kukhuthala kwa pore solution kuchulukirachulukira, motero kutsekereza kuyenda kwa ayoni ndikuchedwetsa kukomoka. Komabe, Pourchez et al. ankakhulupirira kuti panali mgwirizano woonekeratu pakati pa kuchedwa kwa cellulose ether kupita ku simenti hydration ndi kukhuthala kwa simenti slurry. Chiphunzitso china ndi chakuti kuchedwetsa kwa cellulose ether kumagwirizana kwambiri ndi kuwonongeka kwa alkali. Ma polysaccharides amakonda kunyozeka mosavuta kuti apange hydroxyl carboxylic acid yomwe imatha kuchedwetsa kuyatsa kwa simenti pansi pamikhalidwe yamchere. Komabe, kafukufuku wapeza kuti cellulose ether ndi wokhazikika kwambiri pansi pa zinthu zamchere ndipo amangowonongeka pang'ono, ndipo kuwonongeka kuli ndi zotsatira zochepa pa kuchedwa kwa simenti hydration. Pakalipano, lingaliro losasinthika ndiloti kuchedwetsa kumabwera makamaka chifukwa cha kutsatsa. Makamaka, gulu la hydroxyl pa maselo a cellulose ether ndi acidic, ca (0H) mu dongosolo la simenti ya hydration, ndi magawo ena amchere ndi amchere. Pansi pa synergistic kanthu wa hydrogen kugwirizana, complexing ndi hydrophobic, acidic mapadi etere mamolekyulu adzakhala adsorbed padziko zamchere simenti particles ndi mankhwala hydration. Kuphatikiza apo, filimu yopyapyala imapangidwa pamwamba pake, yomwe imalepheretsa kukula kwa ma mineral phase crystal nuclei ndikuchedwetsa hydration ndi kukhazikitsa simenti. Kuchuluka kwa mphamvu ya adsorption pakati pa zinthu za simenti za hydration ndi cellulose ether, m'pamenenso zimawonekera kwambiri kuchedwa kwa simenti. Kumbali imodzi, kukula kwa steric chotchinga kumachita gawo lalikulu pakutsatsa kwamphamvu, monga cholepheretsa chaching'ono cha hydroxyl gulu, acidity yake yolimba, ma adsorption ndi amphamvu. Kumbali inayi, mphamvu ya adsorption imadaliranso kapangidwe kazinthu za simenti za hydration. Pourchez et al. anapeza kuti mapadi efa mosavuta adsorbed pamwamba mankhwala hydration monga ca(0H)2, csH gel osakaniza ndi kashiamu aluminiyamu hydrate, koma si zophweka adsorbed ndi ettringite ndi unhydrated gawo. Kafukufuku wa Mullert adawonetsanso kuti cellulose ether inali ndi adsorption yamphamvu pa c3s ndi zinthu zake za hydration, kotero kuti hydration ya silicate gawo idachedwa kwambiri. Kutsatsa kwa ettringite kunali kochepa, koma mapangidwe a ettringite adachedwa kwambiri. Izi zinali chifukwa kuchedwa kwa mapangidwe a ettringite kunakhudzidwa ndi ca2 + balance mu solution, yomwe inali kupitiriza kwa kuchedwa kwa cellulose ether mu silicate hydration.

3.2 Kusunga Madzi

Chinthu chinanso chofunikira chosinthira ma cellulose ether mumatope a simenti ndikuwoneka ngati chosungira madzi, chomwe chingalepheretse chinyontho mumatope onyowa kuti chisasunthike msanga kapena kutengeka ndi maziko, ndikuchedwetsa ma hydration a simenti ndikuwonjezera nthawi yogwira ntchito. matope onyowa, kuti awonetsetse kuti matope opyapyala atha kupesedwa, matope opakidwa amatha kufalikira, ndipo matope osavuta kuyamwa sayenera kunyowa kale.

Mphamvu yokhala ndi madzi ya cellulose ether imagwirizana kwambiri ndi kukhuthala kwake, mlingo, mtundu ndi kutentha kozungulira. Zinthu zina zimakhala zofanana, kuchulukirachulukira kwa cellulose ether, kumapangitsa kuti madzi asungidwe bwino, kachulukidwe kakang'ono ka cellulose ether kumapangitsa kuti madzi asungidwe mumatope kwambiri; Kwa cellulose ether yemweyo, kuchuluka kwa kuchuluka komwe kumawonjezeredwa, kumapangitsa kuti madzi asungidwe matope osinthidwa, koma pali mtengo wabwino kwambiri, kupitilira komwe kuchuluka kwa kusungirako madzi kumawonjezeka pang'onopang'ono. Pamitundu yosiyanasiyana ya cellulose ether, palinso kusiyana pakusunga madzi, monga HPMc pansi pamikhalidwe yomweyi kuposa kusungirako madzi kwa Mc bwino. Kuphatikiza apo, kasungidwe kamadzi ka cellulose ether kumachepa ndi kuwonjezeka kwa kutentha kozungulira.

Nthawi zambiri amakhulupirira kuti chifukwa cellulose etha ali ndi ntchito ya kusunga madzi makamaka chifukwa cha 0H pa molekyulu ndi 0 atomu pa chomangira efa adzakhala kugwirizana ndi mamolekyu madzi kupanga hydrogen chomangira, kuti madzi aulere amakhala kumanga. madzi, kuti agwire ntchito yabwino yosungira madzi; Amakhulupiriranso kuti unyolo wa cellulose etha macromolecular umagwira ntchito yoletsa kufalikira kwa mamolekyu amadzi, kuti azitha kuwongolera kutuluka kwa madzi, kuti akwaniritse kusungirako madzi ambiri; Pourchez J adanena kuti cellulose ether inakwaniritsa kusungirako madzi mwa kukonza rheological properties za slurry yatsopano yosakanikirana ya simenti, mapangidwe a porous network ndi mapangidwe a cellulose ether filimu yomwe imalepheretsa kufalikira kwa madzi. Laetitia P et al. amakhulupiriranso kuti rheological katundu wa matope ndi chinthu chofunika kwambiri, komanso amakhulupirira kuti mamasukidwe akayendedwe si chinthu chokhacho kudziwa zabwino kwambiri madzi posungira ntchito matope. Ndizofunikira kudziwa kuti ngakhale cellulose ether ali ndi ntchito yabwino yosungira madzi, koma kuyamwa kwake kokhazikika kwa simenti kumachepetsedwa, chifukwa chake ndikuti cellulose ether mu filimu yamatope, ndi mumatope ambiri ang'onoang'ono otsekedwa pores, kutsekereza. matope mkati mwa capillary.

3.3 Kuchulukitsa

Kusasinthika kwa matope ndi chimodzi mwazinthu zofunika kwambiri zoyezera momwe ntchito yake ikuyendera. Cellulose ether nthawi zambiri imayambitsidwa kuti iwonjezere kusasinthika. "Kusasinthasintha" kumayimira kuthekera kwa matope osakanikirana omwe amatha kuyenda ndi kupunduka pansi pa mphamvu yokoka kapena mphamvu zakunja. Zinthu ziwiri za thickening ndi kusunga madzi zimagwirizana. Kuwonjezera mlingo woyenera wa cellulose ether sangakhoze kokha kusintha madzi posungira ntchito matope, kuonetsetsa yosalala yomanga, komanso kuonjezera kugwirizana kwa matope, kwambiri kuonjezera odana ndi kubalalitsidwa luso la simenti, kusintha chomangira ntchito pakati matope ndi masanjidwewo, ndi kuchepetsa kusungunuka kwa matope.

Kukhuthala kwa cellulose ether makamaka kumachokera ku mamasukidwe ake ake, kukhuthala kwakukulu, kumapangitsanso kukhuthala bwino, koma ngati mamasukidwe ake ndi akulu kwambiri, amachepetsa kutulutsa kwamatope, zomwe zimakhudza ntchito yomanga. Zinthu zomwe zimakhudza kusintha kwa viscosity, monga kulemera kwa maselo (kapena digiri ya polymerization) ndi ndende ya cellulose ether, kutentha kwa yankho, kumeta ubweya wa ubweya, zidzakhudza kuwonjezereka komaliza.

Kukhuthala kwa cellulose ether makamaka kumachokera ku hydration ndi kupindika pakati pa mamolekyu. Kumbali imodzi, unyolo wa polima wa cellulose ether ndi wosavuta kupanga chomangira cha haidrojeni ndi madzi m'madzi, chomangira cha haidrojeni chimapangitsa kukhala ndi hydration yayikulu; Komano, pamene mapadi a cellulose awonjezeredwa kumatope, amamwa madzi ambiri, kotero kuti voliyumu yakeyo ikukulitsidwa kwambiri, kuchepetsa malo omasuka a tinthu tating'onoting'ono, nthawi yomweyo mapadi a cellulose etha unyolo wa maselo amalumikizana wina ndi mzake. kupanga mapangidwe atatu azithunzithunzi maukonde, matope particles azunguliridwa mmene, osati otaya ufulu. Mwa kuyankhula kwina, pansi pazigawo ziwirizi, kukhuthala kwa dongosolo kumapangidwa bwino, motero kumakwaniritsa zofuna za thickening.

4. Zotsatira za nonionic cellulose ether pa morphology ndi pore kapangidwe ka polima simenti.

Monga tawonera pamwambapa, ether yosakhala ya ionic cellulose imagwira ntchito yofunika kwambiri mu simenti ya polima, ndipo kuwonjezera kwake kudzakhudzanso mawonekedwe a microstructure a matope onse a simenti. Zotsatira zimasonyeza kuti sanali ionic mapadi efa zambiri kumawonjezera porosity matope simenti, ndipo chiwerengero cha pores kukula 3nm ~ 350um ukuwonjezeka, mwa amene chiwerengero cha pores mu osiyanasiyana 100nm ~ 500nm kumawonjezera kwambiri. Chikoka pa pore dongosolo la simenti matope ndi zogwirizana kwambiri mtundu ndi mamasukidwe akayendedwe a non-ionic cellulose ether anawonjezera. Ou Zhihua et al. ankakhulupirira kuti pamene mamasukidwe akayendedwe ali ofanana, porosity ya matope simenti kusinthidwa ndi HEC ndi yaing'ono kuposa HPMc ndi Mc anawonjezera monga modifiers. Kwa ether ya cellulose yomweyi, yaying'ono ma viscosity, ndi yaying'ono porosity ya matope osinthidwa a simenti. Pophunzira momwe HPMc imagwirira ntchito pobowola bolodi la thovu la simenti, Wang Yanru et al. adapeza kuti kuwonjezera kwa HPMC sikusintha kwambiri porosity, koma kungachepetse kwambiri pobowo. Komabe, Zhang Guoian et al. adapeza kuti kuchuluka kwa HEMc kumapangitsa kuti pakhale chikoka pa pore ya simenti slurry. Kuwonjezera kwa HEMc kumatha kuonjezera kwambiri porosity, kuchuluka kwa pore ndi pafupifupi pore yozungulira ya simenti, koma malo enieni a pore amachepetsa, ndipo chiwerengero cha pores chachikulu cha capillary chachikulu kuposa 50nm m'mimba mwake chikuwonjezeka kwambiri, ndipo pores anayambitsa. makamaka otsekedwa pores.

Zotsatira za nonionic cellulose ether pakupanga mapangidwe a simenti slurry pore dongosolo adawunikidwa. Iwo anapeza kuti Kuwonjezera mapalo ether makamaka anasintha zimatha madzi gawo. Kumbali imodzi, madzi gawo padziko mavuto amachepetsa, kupangitsa kukhala kosavuta kupanga thovu mu matope simenti, ndipo m'mbuyo madzi gawo ngalande ndi kuwira kufalikira, kuti thovu ang'onoang'ono n'zovuta kusonkhanitsa mu thovu lalikulu ndi kumaliseche, kotero kusanja. kuchuluka kwambiri; Komano, mamasukidwe akayendedwe a madzi gawo ukuwonjezeka, amenenso linalake ndipo tikulephera ngalande, kuwira kufalikira ndi kuwira kuphatikiza, ndi timapitiriza luso kukhazikika thovu. Choncho, chikoka mumalowedwe a mapadi efa pa pore kukula kugawa matope simenti akhoza analandira: mu pore kukula osiyanasiyana oposa 100nm, thovu akhoza anayambitsa ndi kuchepetsa mavuto padziko la madzi gawo, ndi kuwira kufalikira akhoza choletsedwa ndi. kuwonjezera kukhuthala kwamadzi; m'chigawo cha 30nm ~ 60nm, kuchuluka kwa pores m'derali kungakhudzidwe ndi kuletsa kuphatikiza kwa thovu laling'ono.

5. Mphamvu ya nonionic cellulose ether pa makina a simenti ya polima

Zomwe zimapangidwira za simenti ya polima zimagwirizana kwambiri ndi mawonekedwe ake. Ndi kuwonjezera kwa nonionic cellulose ether, porosity imawonjezeka, yomwe imayenera kukhala ndi zotsatira zoipa pa mphamvu zake, makamaka mphamvu yopondereza ndi mphamvu yosinthasintha. Kuchepetsa mphamvu yopondereza ya matope a simenti ndikokulirapo kuposa mphamvu yopindika. Ou Zhihua et al. anaphunzira chikoka cha mitundu yosiyanasiyana ya sanali ionic mapadi efa pa makina katundu wa simenti matope, ndipo anapeza kuti mphamvu ya mapadi etere kusinthidwa simenti matope anali otsika kuposa matope koyera simenti, ndi otsika 28d compressive mphamvu anali 44,3% yokha. za matope a simenti. Mphamvu yopondereza ndi mphamvu ya flexural ya HPMc, HEMC ndi MC cellulose ether zosinthidwa ndizofanana, pamene mphamvu yopondereza ndi mphamvu yosinthika ya HEc yosinthidwa simenti slurry mu m'badwo uliwonse ndi apamwamba kwambiri. Izi zimagwirizana kwambiri ndi kukhuthala kwawo kapena kulemera kwa maselo, kukwezeka kwa kukhuthala kapena kulemera kwa maselo a cellulose ether, kapena kukulirapo kwa ntchito yapamtunda, kumachepetsa mphamvu ya matope ake osinthidwa simenti.

Komabe, zasonyezedwanso kuti nonionic cellulose ether ikhoza kupititsa patsogolo mphamvu zamanjenje, kusinthasintha komanso kugwirizanitsa kwamatope a simenti. Huang Liangen et al. anapeza kuti, mosiyana ndi lamulo la kusintha kwa mphamvu yopondereza, mphamvu ya kumeta ubweya ndi mphamvu yowonjezereka ya slurry inawonjezeka ndi kuwonjezeka kwa zomwe zili mu cellulose ether mumatope a simenti. Kusanthula chifukwa, pambuyo Kuwonjezera wa mapadi efa, ndi polima emulsion pamodzi kupanga ambiri wandiweyani polima filimu, kwambiri kusintha kusinthasintha kwa slurry, ndi simenti hydration mankhwala, simenti unhydrated, fillers ndi zipangizo zina wodzazidwa mu filimuyi. , kuonetsetsa kuti mphamvu yamagetsi yamagetsi imakhala yolimba.

Kuti patsogolo ntchito sanali ionic mapadi etere kusinthidwa polima simenti, kusintha thupi katundu wa simenti matope pa nthawi yomweyo, si kwambiri kuchepetsa mawotchi katundu wake, mchitidwe mwachizolowezi ndi kufananitsa mapadi etere ndi admixtures ena, anawonjezera kuti matope a simenti. Li Tao-wen et al. adapeza kuti chophatikizira chopangidwa ndi cellulose ether ndi polima guluu ufa sichimangowonjezera pang'ono mphamvu yopindika ndi mphamvu yopondereza yamatope, kotero kuti mgwirizano ndi kukhuthala kwa matope a simenti ndizoyenera kwambiri pakumanga zokutira, komanso kumathandizira kwambiri kusunga madzi. mphamvu yamatope poyerekeza ndi cellulose ether imodzi. Xu Qi et al. anawonjezera slag ufa, madzi kuchepetsa wothandizira ndi HEMc, ndipo anapeza kuti madzi kuchepetsa wothandizila ndi mchere ufa akhoza kuonjezera kachulukidwe matope, kuchepetsa chiwerengero cha mabowo, kuti patsogolo mphamvu ndi zotanuka modulus matope. HEMc imatha kukulitsa mphamvu yomangira yamatope, koma si yabwino ku mphamvu yopondereza ndi zotanuka modulus yamatope. Yang Xiaojie et al. anapeza kuti pulasitiki shrinkage kusweka kwa matope simenti akhoza kuchepetsedwa kwambiri pambuyo kusakaniza HEMc ndi PP CHIKWANGWANI.

6. Mapeto

Nonionic mapadi efa mbali yofunika kwambiri polima simenti, amene kwambiri kusintha thupi katundu (kuphatikizapo retarding coagulation, posungira madzi, thickening), morphology tosaoneka ndi mawotchi katundu matope simenti. Ntchito yochuluka yachitika pa kusinthidwa kwa zipangizo zopangira simenti ndi cellulose ether, komabe pali mavuto omwe amafunikira kuphunzira. Mwachitsanzo, mu ntchito zaumisiri wothandiza, chidwi chochepa chimaperekedwa ku ma rheology, ma deformation, kukhazikika kwa voliyumu komanso kulimba kwa zida zosinthidwa za simenti, ndipo ubale wofananira sunakhazikitsidwe ndi ether yowonjezeredwa ya cellulose. Kafukufuku wokhudza kusamuka kwa cellulose ether polima ndi zinthu za simenti za hydration mu hydration reaction akadali osakwanira. The kanthu ndondomeko ndi limagwirira wa pawiri zina wopangidwa ndi mapadi efa ndi zina admixtures si bwino mokwanira. Kuphatikizika kophatikiza kwa cellulose ether ndi zinthu zolimbitsa thupi monga magalasi ulusi sikunakwaniritsidwe. Zonsezi zikhala cholinga cha kafukufuku wamtsogolo kuti apereke chitsogozo chamalingaliro kuti apititse patsogolo magwiridwe antchito a simenti ya polima.