I-Admixtures idlala indima ephambili ekuphuculeni ukusebenza kwesakhiwo sodaka oluxutyiweyo, kodwa ukongezwa kodaka oluxutyiweyo oluxubeneyo kwenza ukuba iindleko zempahla yemveliso yodaka eyomileyo ibe phezulu kakhulu kunodaka lwemveli, olubalelwa ngaphezulu kwe-40% yodaka. ixabiso lezinto eziphathekayo kudaka oluxubeneyo elomileyo. Okwangoku, inxalenye enkulu ye-admixture inikezelwa ngabavelisi bamazwe angaphandle, kwaye idosi yereferensi yemveliso inikezelwa ngumthengisi. Ngenxa yoko, ixabiso leemveliso zodaka oluxutyiweyo luhlala luphezulu, kwaye kunzima ukuvakalisa i-masonry eqhelekileyo kunye ne-plastering mortars ezinobuninzi kunye neendawo ezibanzi; iimveliso zentengiso ezikumgangatho ophezulu zilawulwa ziinkampani zangaphandle, kwaye abenzi bodaka oluxubeneyo olomileyo banengeniso ephantsi kunye nokunyamezela amaxabiso aphantsi; Kukho ukunqongophala kophando olucwangcisiweyo nolujoliswe kuyo malunga nokusetyenziswa kwamayeza, kwaye iifomula zangaphandle zilandelwa ngokungaboniyo.
Ngokusekelwe kwezi zizathu zingasentla, eli phepha lihlalutya kwaye lithelekisa ezinye iimpawu ezisisiseko ze-admixtures ezisetyenziswa ngokuqhelekileyo, kwaye ngenxa yesi siseko, iphonononga ukusebenza kweemveliso zodaka ezinomxube owomileyo usebenzisa i-admixtures.
1. Iarhente yokugcina amanzi
I-ejenti yokugcina amanzi ngumxube obalulekileyo wokuphucula ukugcinwa kwamanzi omdaka odibeneyo owomileyo, kwaye ikwayenye yezinto ezidityanisiweyo eziphambili zokumisela ixabiso lezinto ezixutywe ngodaka.
1.1 Iselulosi ether
I-ether ye-cellulose ligama eliqhelekileyo loluhlu lweemveliso eziveliswa yi-reaction ye-alkali cellulose kunye ne-etherifying agent phantsi kweemeko ezithile. I-alkali cellulose ithathelwa indawo ngama-ejenti ahlukeneyo etherifying ukufumana i-ethers ye-cellulose eyahlukeneyo. Ngokweepropathi ze-ionization ze-substituents, i-cellulose ethers inokwahlulwa ibe ngamacandelo amabini: ionic (efana ne-carboxymethyl cellulose) kunye ne-non-ionic (njenge-methyl cellulose). Ngokohlobo lwe-substituent, i-cellulose ether inokohlulwa ibe yi-monoether (efana ne-methyl cellulose) kunye ne-ether exutywe (njenge-hydroxypropyl methyl cellulose). Ngokutsho kwe-solubility eyahlukileyo, inokwahlulwa ibe yi-soluble yamanzi (efana ne-hydroxyethyl cellulose) kunye ne-organic solvent-soluble (efana ne-ethyl cellulose), njl njl. yahlulwe ngokohlobo olukhawulezileyo kunye nomgangatho onyangwayo wokulibaziseka uhlobo lokupheliswa.
Indlela yokusebenza ye-cellulose ether kumdaka ihamba ngolu hlobo lulandelayo:
(1) Emva kokuba i-ether cellulose kumdaka inyibilikiswe emanzini, ukuhanjiswa okusebenzayo kunye okufanayo kwesixhobo se-cementitious kwinkqubo kuqinisekiswa ngenxa yomsebenzi ongaphezulu, kunye ne-cellulose ether, njenge-colloid ekhuselayo, "isonga" into eqinileyo. amasuntswana kunye Umaleko wefilimu yokuthambisa yenziwa kwindawo yayo yangaphandle, eyenza inkqubo yodaka izinze ngakumbi, kwaye iphucula umbane wodaka ngexesha lenkqubo yokuxuba kunye. ukuguda kolwakhiwo.
(2) Ngenxa yolwakhiwo lwalo lwemolekyuli, isisombululo se-ether se-cellulose senza ukuba amanzi kumdaka angabi lula ukulahleka, kwaye ngokuthe ngcembe akhuphe ixesha elide, enika udaka ngokugcinwa kakuhle kwamanzi kunye nokusebenza.
1.1.1 Ifomula yemolekyuli ye-methyl cellulose (MC) [C6H7O2(OH)3-h(OCH3)n]x
Emva kokuba umqhaphu osulungekisiweyo uphathwe ngealkali, i-cellulose ether iveliswa ngothotho lweempendulo ngemethane chloride njenge-etherification agent. Ngokubanzi, iqondo lokutshintsha liyi-1.6 ~ 2.0, kwaye ukunyibilika kwahluka ngokwamanqanaba okutshintsha. yeye-non-ionic cellulose ether.
(1) I-Methylcellulose iyanyibilika emanzini abandayo, kwaye kuya kuba nzima ukuyinyibilika emanzini ashushu. Isisombululo saso samanzi sizinzile kakhulu kuluhlu lwe-pH = 3 ~ 12. Inokuhambelana kakuhle nestatshi, i-guar gum, njl. kunye nee-surfactants ezininzi. Xa iqondo lokushisa lifikelela kwiqondo lokushisa, i-gelation iyenzeka.
(2) Ukugcinwa kwamanzi kwe-methyl cellulose kuxhomekeke kwisixa sokongeza, i-viscosity, i-particle fineness kunye nesantya sokuchithwa. Ngokuqhelekileyo, ukuba isixa esongezelelweyo sikhulu, i-fineness incinci, kwaye i-viscosity inkulu, izinga lokugcinwa kwamanzi liphezulu. Phakathi kwabo, inani lokongezelela linempembelelo enkulu kwizinga lokugcinwa kwamanzi, kwaye inqanaba le-viscosity alilingani ngokuthe ngqo kwinqanaba lokugcinwa kwamanzi. Izinga lokuchithwa ikakhulu lixhomekeke kwiqondo lokuguqulwa komphezulu wamasuntswana e-cellulose kunye ne-particle fineness. Phakathi kwezi ether ze-cellulose ezingentla, i-methyl cellulose kunye ne-hydroxypropyl methyl cellulose zinezinga eliphezulu lokugcina amanzi.
(3) Utshintsho kwiqondo lobushushu luya kuchaphazela kakhulu izinga lokugcinwa kwamanzi kwi-methyl cellulose. Ngokuqhelekileyo, okukhona ubushushu buphezulu, kokukhona ukugcinwa kwamanzi kubi. Ukuba ubushushu bomdaka budlula i-40 ° C, ukugcinwa kwamanzi kwe-methyl cellulose kuya kuncitshiswa kakhulu, kuchaphazela kakhulu ukwakhiwa kodaka.
(4) I-Methyl cellulose inempembelelo ebalulekileyo ekwakhiweni nasekunamatheleni komdaka. “Ukuncamathisela” apha kubhekisa kumandla okuncamathelisa okuvakala phakathi kwesixhobo sokufaka isicelo somsebenzi kunye nenxalenye yodonga, oko kukuthi, ukuxhathisa kokucheba kodaka. I-adhesiveness iphezulu, ukuxhathisa i-shear yodaka kukhulu, kwaye amandla afunwa ngabasebenzi kwinkqubo yokusetyenziswa nawo mkhulu, kwaye ukusebenza kokwakhiwa kodaka kubi. I-Methyl cellulose adhesion ikwinqanaba eliphakathi kwiimveliso ze-cellulose ether.
1.1.2 Ifomula yemolekyuli ye-hydroxypropyl methylcellulose (HPMC) yi [C6H7O2(OH)3-mn(OCH3)m,OCH2CH(OH)CH3]n]x
IHydroxypropyl methylcellulose luhlobo lweselulosi oluphuma kunye nokusetyenziswa kwayo kuye kwanda ngokukhawuleza kwiminyaka yakutshanje. I-ether engeyiyo ionic cellulose exutywe ne-ether eyenziwe kwi-cotton ecocekileyo emva kwe-alkalization, isebenzisa i-propylene oxide kunye ne-methyl chloride njenge-etherification agent, ngokusebenzisa uluhlu lweempendulo. Iqondo lokutshintshwa ngokubanzi yi-1.2 ~ 2.0. Iimpawu zayo zihluke ngenxa yemilinganiselo eyahlukeneyo yomxholo we-methoxyl kunye nomxholo we-hydroxypropyl.
(1) IHydroxypropyl methylcellulose inyibilika ngokulula emanzini abandayo, kwaye iya kudibana nobunzima ekunyibilikeni kumanzi ashushu. Kodwa ubushushu bayo be-gelation emanzini ashushu buphezulu kakhulu kune-methyl cellulose. Ukunyibilika kumanzi abandayo kuphuculwe kakhulu xa kuthelekiswa ne-methyl cellulose.
(2) I-viscosity ye-hydroxypropyl methylcellulose ihambelana nobunzima bayo be-molecular, kwaye ubukhulu be-molecular weight, buphezulu be-viscosity. Ubushushu buchaphazela i-viscosity yayo, njengoko izinga lokushisa linyuka, i-viscosity iyancipha. Nangona kunjalo, i-viscosity yayo ephezulu inefuthe eliphantsi lobushushu kune-methyl cellulose. Isisombululo sayo sizinzile xa sigcinwe kwiqondo lokushisa.
(3) Ukugcinwa kwamanzi kwe-hydroxypropyl methylcellulose kuxhomekeke kwisixa sokongeza, i-viscosity, njl.
(4) I-Hydroxypropyl methylcellulose izinzile kwi-asidi kunye ne-alkali, kwaye isisombululo sayo samanzi sizinzileyo kakhulu kwi-pH = 2 ~ 12. I-Caustic soda kunye namanzi e-lime anempembelelo encinci ekusebenzeni kwayo, kodwa i-alkali inokukhawulezisa ukuchithwa kwayo kunye nokwandisa i-viscosity yayo. I-Hydroxypropyl methylcellulose izinzile kwiityuwa eziqhelekileyo, kodwa xa ukuxinwa kwesisombululo setyuwa kuphezulu, i-viscosity ye-hydroxypropyl methylcellulose isisombululo ivame ukunyuka.
(5) I-Hydroxypropyl methylcellulose inokuxutywa kunye ne-polymer compounds e-soluble yamanzi ukuze yenze isisombululo esifanayo kunye ne-viscosity ephezulu. Okufana ne-polyvinyl alcohol, i-starch ether, i-gum yemifuno, njl.
(6) I-Hydroxypropyl methylcellulose inokumelana ne-enzyme engcono kune-methylcellulose, kwaye isisombululo sayo asikwazi ukuthotywa yi-enzymes kune-methylcellulose.
(7) I-adhesion ye-hydroxypropyl methylcellulose kwisakhiwo sodaka iphezulu kune-methylcellulose.
1.1.3 I-Hydroxyethylcellulose (HEC)
Yenziwe kwikotoni esulungekileyo ephathwe nge-alkali, kwaye iphendule nge-ethylene oxide njenge-etherification agent phambi kwe-acetone. Iqondo lokutshintshwa ngokubanzi yi-1.5 ~ 2.0. Ine-hydrophilicity eyomeleleyo kwaye kulula ukufunxa ukufuma.
(1) I-Hydroxyethyl cellulose iyanyibilika emanzini abandayo, kodwa kunzima ukuyinyibilika emanzini ashushu. Isisombululo saso sizinzile kwiqondo lokushisa eliphezulu ngaphandle kwe-gelling. Ingasetyenziselwa ixesha elide phantsi kobushushu obuphezulu kwidaka, kodwa ukugcinwa kwamanzi kwayo kuphantsi kune-methyl cellulose.
(2) I-Hydroxyethyl cellulose izinzile kwi-asidi ngokubanzi kunye ne-alkali. I-alkali inokukhawulezisa ukuchithwa kwayo kwaye inyuse kancinci i-viscosity yayo. I-dispersibility yayo emanzini imbi kancinane kune-methyl cellulose kunye ne-hydroxypropyl methyl cellulose. .
(3) I-Hydroxyethyl cellulose inokusebenza kakuhle kwe-anti-sag yodaka, kodwa inexesha elide lokubuyiswa kwesamente.
(4) Ukusebenza kwe-hydroxyethyl cellulose eveliswa ngamanye amashishini asekhaya ngokucacileyo isezantsi kune-methyl cellulose ngenxa yobuninzi bamanzi kunye nomxholo ophezulu wothuthu.
1.1.4 Carboxymethylcellulose (CMC) [C6H7O2(OH)2och2COONA]n
I-Ionic cellulose ether yenziwe kwimicu yendalo (ikotoni, njl.njl.) emva konyango lwe-alkali, kusetyenziswa i-sodium monochloroacetate njenge-etherification agent, kwaye iphantsi koluhlu lwezonyango zokusabela. Iqondo lokutshintshwa ngokubanzi yi-0.4 ~ 1.4, kwaye ukusebenza kwayo kuchatshazelwa kakhulu ngumgangatho wokutshintshwa.
(1) I-Carboxymethyl cellulose i-hygroscopic ngakumbi, kwaye iya kuba namanzi amaninzi xa igcinwe phantsi kweemeko eziqhelekileyo.
(2) I-Carboxymethyl cellulose isisombululo samanzi asiyi kuvelisa i-gel, kwaye i-viscosity iya kuncipha ngokunyuka kweqondo lokushisa. Xa iqondo lokushisa lidlula i-50 ° C, i-viscosity ayinakuguqulwa.
(3) Ukuzinza kwayo kuchaphazeleka kakhulu yi-pH. Ngokuqhelekileyo, inokusetyenziswa kwi-gypsum-based mortar, kodwa kungekhona kwi-samente-based mortar. Xa i-alkaline iphezulu, ilahlekelwa yi-viscosity.
(4) Ugcino lwawo lwamanzi lungaphantsi kakhulu kunolo lwemethyl cellulose. Inempembelelo ebambezelayo kwi-gypsum-based mortar kwaye inciphisa amandla ayo. Nangona kunjalo, ixabiso le-carboxymethyl cellulose liphantsi kakhulu kunelo le-methyl cellulose.
Ixesha lokuposa: Mar-30-2023