1. Mitundu ya thickeners ndi thickening limagwirira
(1) Chowonjezera chachilengedwe:
Zokhuthala zosakhala m'madzi m'madzi zimakhala makamaka dongo.Monga: bentonite.Kaolin ndi dziko lapansi la diatomaceous (chigawo chachikulu ndi SiO2, chomwe chili ndi porous) nthawi zina amagwiritsidwa ntchito ngati zowonjezera zowonjezera zowonjezera chifukwa cha kuyimitsidwa kwawo.Bentonite imagwiritsidwa ntchito kwambiri chifukwa cha kuchuluka kwake kwamadzi.Bentonite (Bentonite), wotchedwanso bentonite, bentonite, etc., mchere waukulu wa bentonite ndi montmorillonite munali pang'ono zamchere ndi zamchere lapansi zitsulo hydrous aluminosilicate mchere, wa gulu aluminosilicate, ambiri chilinganizo ake mankhwala ndi : (Na. ,Ca)(Al,Mg)6(Si4O10)3(OH)6•nH2O.The kutambasuka ntchito bentonite anasonyeza ndi kukula mphamvu, ndiye buku la bentonite pambuyo kutupa mu kuchepetsa hydrochloric asidi njira amatchedwa kukula mphamvu, anafotokoza mu ml/gram.Pambuyo pa bentonite thickener imamwa madzi ndi kutupa, voliyumu imatha kufika kangapo kapena kakhumi kuti isanayambe kuyamwa madzi, kotero imakhala yabwino kuyimitsidwa, ndipo chifukwa ndi ufa wokhala ndi tinthu tating'onoting'ono, ndi yosiyana ndi ufa wina mu zokutira. dongosolo.Thupi limasinthasintha bwino.Kuonjezera apo, pamene akupanga kuyimitsidwa, amatha kuyendetsa ufa wina kuti apange zotsatira zina zotsutsana ndi stratification, choncho zimathandiza kwambiri kupititsa patsogolo kusungidwa kwa dongosolo.
Koma ma bentonite ambiri okhala ndi sodium amasinthidwa kuchokera ku bentonite yochokera ku calcium kudzera mu kutembenuka kwa sodium.Pa nthawi yomweyi ya sodiumization, ma ions ambiri abwino monga calcium ions ndi sodium ions adzapangidwa.Ngati zili za cations mu dongosolo ndi okwera kwambiri, kuchuluka kwa ndalama neutralization adzakhala kwaiye pa mlandu zoipa padziko emulsion, kotero kumlingo wakuti, Zingayambitse mavuto monga kutupa ndi flocculation wa. emulsion.Kumbali inayi, ayoni a calcium awa adzakhalanso ndi zotsatira zoyipa pa sodium salt dispersant (kapena polyphosphate dispersant), zomwe zimapangitsa kuti ma dispersant awa adutse mu dongosolo la zokutira, zomwe zimadzetsa kutayika kwa kubalalitsidwa, kupangitsa kuti ❖ kuyanika, kukhuthala kapena ngakhale. wandiweyani.Kunagwa mvula yambiri komanso kusefukira.Komanso, thickening zotsatira za bentonite makamaka amadalira ufa kuyamwa madzi ndi kukulitsa kubala kuyimitsidwa, kotero adzabweretsa amphamvu thixotropic zotsatira kwa ❖ kuyanika dongosolo, amene ndi zoipa kwambiri zokutira zimene zimafuna zabwino kusalaza zotsatira.Choncho, ma bentonite thickeners sagwiritsidwa ntchito kawirikawiri mu utoto wa latex, ndipo pang'ono chabe amagwiritsidwa ntchito ngati zowonjezera mu utoto wochepa wa latex kapena utoto wa latex.Komabe, m'zaka zaposachedwa, zina zawonetsa kuti Hemmings' BENTONE®LT.hectorite yosinthidwa mwachilengedwe komanso yoyengedwa imakhala ndi zotsatira zabwino zotsutsana ndi sedimentation ndi atomization ikagwiritsidwa ntchito ku makina opoperapo opanda mpweya.
(2) Ma cellulose ether:
Cellulose ether ndi polima wapamwamba kwambiri wachilengedwe wopangidwa ndi kukhazikika kwa β-glucose.Pogwiritsa ntchito mawonekedwe a gulu la hydroxyl mu mphete ya glucosyl, cellulose amatha kuchita zinthu zosiyanasiyana kuti apange zotumphukira zingapo.Pakati pawo, esterification ndi etherification reactions amapezeka.Ma cellulose ester kapena cellulose ether ndi omwe amafunikira kwambiri pa cellulose.Zomwe zimagwiritsidwa ntchito kwambiri ndi carboxymethyl cellulose,hydroxyethyl cellulose, methyl cellulose, hydroxypropyl methyl cellulose ndi zina zotero.Chifukwa carboxymethyl cellulose imakhala ndi ayoni a sodium omwe amasungunuka mosavuta m'madzi, imakhala yosakanizidwa bwino ndi madzi, ndipo chiwerengero cha zolowa m'malo mwake ndi yaying'ono, motero imawonongeka mosavuta ndi dzimbiri la bakiteriya, kuchepetsa kukhuthala kwa njira yamadzimadzi ndikuipanga. onunkhira, ndi zina zotero. Chodabwitsa, chomwe sichimagwiritsidwa ntchito kawirikawiri mu utoto wa latex, womwe umagwiritsidwa ntchito popanga utoto wamtundu wa polyvinyl mowa womatira ndi putty.Mlingo wa kusungunuka kwa madzi wa methylcellulose nthawi zambiri umakhala wotsika pang'ono kuposa wa hydroxyethylcellulose.Kuonjezera apo, pakhoza kukhala zinthu zochepa zomwe sizingasungunuke panthawi ya kusungunuka, zomwe zingakhudze maonekedwe ndi kumverera kwa filimu yophimba, kotero siigwiritsidwe ntchito kawirikawiri mu utoto wa latex.Komabe, kuthamanga kwapamtunda kwa methyl aqueous solution ndi yotsika pang'ono poyerekeza ndi njira zina zama cellulose amadzimadzi, kotero ndi bwino cellulose thickener ntchito putty.Hydroxypropyl methylcellulose imakhalanso thickener ya cellulose yomwe imagwiritsidwa ntchito kwambiri popanga putty, ndipo tsopano imagwiritsidwa ntchito makamaka popanga simenti kapena laimu-calcium-based putty (kapena zomangira zina).Ma cellulose a Hydroxyethyl amagwiritsidwa ntchito kwambiri pamakina opaka utoto wa latex chifukwa cha kusungunuka kwake kwamadzi komanso kusunga madzi.Poyerekeza ndi ma cellulose ena, zimakhala ndi zotsatira zochepa pakuchita filimu yophimba.Ubwino wa cellulose wa hydroxyethyl umaphatikizapo kupopera bwino kwambiri, kuyanjana kwabwino, kukhazikika kosungirako bwino, komanso kukhazikika kwa pH kwamakamaka.Zoyipa zake ndi kusayenda bwino kwamadzimadzi komanso kusagwira bwino ntchito kwa kuwomba.Pofuna kukonza zolakwika izi, kusintha kwa hydrophobic kwawonekera.Hydroxyethylcellulose (HMHEC) yokhudzana ndi kugonana monga NatrosolPlus330, 331
(3) Polycarboxylates:
Mu polycarboxylate iyi, kulemera kwakukulu kwa mamolekyu ndi kokonata, ndipo kulemera kwa maselo otsika ndi dispersant.Iwo makamaka adsorb madzi mamolekyu mu unyolo waukulu wa dongosolo, amene kumawonjezera mamasukidwe akayendedwe a obalalika gawo;Komanso, iwo mwina adsorbed padziko lalabala particles kupanga ❖ kuyanika wosanjikiza, amene kumawonjezera tinthu kukula lalabala, thickens ndi hydration wosanjikiza wa lalabala, ndipo kumawonjezera mamasukidwe akayendedwe a mkati gawo la latex.Komabe, mtundu uwu wa thickener uli ndi mphamvu yochepetsetsa yowonjezereka, choncho imachotsedwa pang'onopang'ono muzopaka.Tsopano mtundu uwu wa thickener umagwiritsidwa ntchito makamaka pakukula kwa phala lamtundu, chifukwa kulemera kwake kwa maselo ndi kwakukulu, kotero kumathandiza kuti dispersibility ndi kusungirako kusungidwe kwa phala lamtundu.
(4) Chokhuthala cha alkali:
Pali mitundu iwiri ikuluikulu ya zokhuthala za alkali: zokhuthala wamba za alkali komanso zokhuthala za alkali.Kusiyana kwakukulu pakati pawo ndiko kusiyana kwa ma monomers ogwirizana omwe ali mu unyolo waukulu wa maselo.Associative alkali-swellable thickeners ndi copolymerized ndi asociative monomers kuti akhoza adsorb wina ndi mzake mu dongosolo unyolo waukulu, kotero pambuyo ionization mu njira amadzimadzi, intra-maselo kapena inter-maselo adsorption akhoza kuchitika, kuchititsa mamasukidwe akayendedwe a dongosolo kuwuka mofulumira.
a.Wamba alkali-swellable thickener:
Choyimira chachikulu chamtundu wa alkali-swellable thickener ndi ASE-60.ASE-60 makamaka utenga copolymerization wa asidi methacrylic ndi ethyl acrylate.Panthawi ya copolymerization, methacrylic acid imakhala pafupifupi 1/3 ya zinthu zolimba, chifukwa kupezeka kwa magulu a carboxyl kumapangitsa kuti unyolo wa maselo ukhale ndi hydrophilicity, ndikulepheretsa kupanga mchere.Chifukwa cha kuthamangitsidwa kwa zolipiritsa, maunyolo a molekyulu amakulitsidwa, zomwe zimawonjezera kukhuthala kwa dongosololi ndikupanga kukhuthala.Komabe, nthawi zina kulemera kwa mamolekyu kumakhala kwakukulu kwambiri chifukwa cha zochita za wothandizira wogwirizanitsa.Pakukulitsa kwa unyolo wa mamolekyu, unyolo wa mamolekyulu sunabalalika bwino pakanthawi kochepa.Panthawi yosungirako nthawi yayitali, unyolo wa maselo umatambasulidwa pang'onopang'ono, zomwe zimabweretsa Post-thickening of viscosity.Kuphatikiza apo, chifukwa pali ma monomers ochepa a hydrophobic muunyolo wamtundu uwu wa thickener, sikophweka kupanga hydrophobic complexation pakati pa mamolekyu, makamaka kupanga intramolecular mutual adsorption, kotero mtundu uwu wa thickener umakhala ndi magwiridwe antchito otsika, kotero ndi osagwiritsidwa ntchito kawirikawiri.Amagwiritsidwa ntchito makamaka kuphatikiza ndi zina zonenepa.
b.Association (concord) mtundu alkali kutupa thickener:
Mtundu uwu wa thickener tsopano uli ndi mitundu yambiri chifukwa cha kusankha ma monomers ogwirizana ndi mapangidwe a maselo.Kapangidwe kake kaunyolo kakang'ono kumapangidwanso makamaka ndi methacrylic acid ndi ethyl acrylate, ndipo ma monomers ogwirizana ali ngati tinyanga pamapangidwe, koma kugawa pang'ono.Ndi ma asociative monomers ngati ma octopus tentacles omwe amagwira ntchito yofunika kwambiri pakukulitsa mphamvu ya thickener.Gulu la carboxyl mu kapangidwe kake ndi losasunthika komanso lopanga mchere, ndipo unyolo wa mamolekyulu ulinso ngati wamba wamba wa alkali-swellable thickener.Chomwecho chiwongolero chothamangitsidwa chimachitika, kotero kuti unyolo wa ma molekyulu umayamba.The associative monomer mmenemo imakulanso ndi unyolo wa maselo, koma kapangidwe kake kali ndi maunyolo onse a hydrophilic ndi unyolo wa hydrophobic, kotero mawonekedwe akulu a micellar ofanana ndi ma surfactants adzapangidwa mu molekyulu kapena pakati pa mamolekyu.Ma micelles amapangidwa ndi kulumikizana kwa mgwirizano wa ma monomers, ndipo ma monomers ena amalumikizana wina ndi mnzake kudzera mukuphatikizika kwa tinthu tating'ono ta emulsion (kapena tinthu tating'ono).Pambuyo pa ma micelles amapangidwa, amakonza tinthu tating'onoting'ono ta emulsion, tinthu tating'onoting'ono tamadzi kapena tinthu tating'ono tating'onoting'ono m'malo osasunthika monga momwe zimakhalira mpanda, kotero kuti kuyenda kwa mamolekyu (kapena particles) kumafowoka komanso kukhuthala kwa ma cell. kuwonjezeka kwa ndondomeko.Choncho, kukhuthala kwa mtundu uwu wa thickener, makamaka mu utoto wa latex wokhala ndi emulsion wambiri, ndi wapamwamba kwambiri kuposa wamba wamba alkali-swellable thickeners, choncho amagwiritsidwa ntchito kwambiri mu utoto wa latex.Woimira wamkulu wa mankhwala Mtundu ndi TT-935.
(5) Associative polyurethane (kapena polyether) thickening ndi leveling wothandizira:
Nthawi zambiri, thickeners ndi mkulu kwambiri maselo kulemera (monga mapadi ndi acrylic asidi), ndi unyolo awo maselo anatambasula amadzimadzi njira kuonjezera mamasukidwe akayendedwe a dongosolo.Kulemera kwa molekyulu ya polyurethane (kapena polyether) ndi yaying'ono kwambiri, ndipo makamaka imapanga mgwirizano kudzera mu kuyanjana kwa mphamvu ya van der Waals ya gawo la lipophilic pakati pa mamolekyu, koma mphamvu yogwirizanitsa iyi ndi yofooka, ndipo mgwirizano ukhoza kupangidwa pansi pa zina. mphamvu yakunja.Kupatukana, potero kuchepetsa mamasukidwe akayendedwe, ndi yabwino kwa mlingo wa ❖ kuyanika filimu, choncho akhoza kutenga udindo wa kusanja wothandizila.Pamene mphamvu yakumeta ubweya itachotsedwa, imatha kuyambiranso kuyanjana, ndipo kukhuthala kwa dongosolo kumawuka.Chodabwitsa ichi ndi chothandiza kuchepetsa mamasukidwe akayendedwe ndi kuonjezera mlingo pomanga;ndipo mphamvu yometa ubweya ikatayika, viscosity idzabwezeretsedwa nthawi yomweyo kuti iwonjezere makulidwe a filimu yophimba.Mu ntchito zothandiza, timakhudzidwa kwambiri ndi kukhuthala kwa ma associative thickeners pa ma emulsion a polima.Waukulu wa polima latex particles nawonso nawo mgwirizano wa dongosolo, kotero kuti mtundu uwu wa thickening ndi kusalaza wothandizila alinso wabwino thickening (kapena kusanja) zotsatira pamene ndi otsika kuposa ndende yake yovuta;pamene ndende ya mtundu uwu wa thickening ndi mlingo wothandizila Pamene ali apamwamba kuposa ndende yake yovuta m'madzi oyera, akhoza kupanga mayanjano palokha, ndi mamasukidwe akayendedwe amawuka mofulumira.Choncho, pamene mtundu uwu wa thickening ndi kuwongolera wothandizila ndi wotsika kuposa ndende yake yovuta, chifukwa tinthu ta latex timatenga nawo mbali mu mgwirizano wapang'onopang'ono, tinthu tating'onoting'ono ta emulsion, mgwirizano wamphamvu, ndi kukhuthala kwake zidzawonjezeka ndi kuwonjezeka kwa kuchuluka kwa emulsion.Kuphatikiza apo, ma dispersants (kapena ma acrylic thickeners) amakhala ndi zida za hydrophobic, ndipo magulu awo a hydrophobic amalumikizana ndi a polyurethane, kotero kuti dongosololi limapanga dongosolo lalikulu la maukonde, lomwe limathandizira kukulitsa.
2. Zotsatira za thickeners zosiyanasiyana pa madzi kulekana kukana kwa latex utoto
Popanga mapangidwe a utoto wamadzi, kugwiritsa ntchito thickeners ndi chiyanjano chofunika kwambiri, chomwe chimagwirizana ndi katundu wambiri wa latex utoto, monga zomangamanga, chitukuko cha mtundu, kusungirako ndi maonekedwe.Apa timayang'ana kwambiri zotsatira za kugwiritsa ntchito thickeners pakusungira utoto wa latex.Kuchokera pamwambapa, tingathe kudziwa kuti bentonite ndi polycarboxylates: thickeners amagwiritsidwa ntchito makamaka mu zokutira zapadera, zomwe sizidzakambidwa pano.Tidzakambirana makamaka za mapadi omwe amagwiritsidwa ntchito kwambiri, kutupa kwa alkali, ndi polyurethane (kapena polyether) thickeners, okha komanso osakaniza, zimakhudza kukana kwa madzi kulekana kwa utoto wa latex.
Ngakhale kukhuthala ndi hydroxyethyl cellulose kokha ndikovuta kwambiri pakulekanitsa madzi, ndikosavuta kusuntha mofanana.Kugwiritsa ntchito kamodzi kokha kukhuthala kwa alkali sikumalekanitsa madzi ndi mvula koma kumakhuthala pambuyo pakukhuthala.Kugwiritsiridwa ntchito kamodzi kwa polyurethane thickening, ngakhale kulekanitsa madzi ndi pambuyo thickening Kukhuthala si koopsa, koma mpweya wopangidwa ndi iyo imakhala yovuta komanso yovuta kugwedeza.Ndipo utenga hydroxyethyl mapadi ndi alkali kutupa thickening pawiri, palibe pambuyo thickening, palibe mpweya wolimba, zosavuta kusonkhezera, koma palinso madzi pang'ono.Komabe, pamene hydroxyethyl cellulose ndi polyurethane zikugwiritsidwa ntchito kukhuthala, kulekanitsa madzi ndikovuta kwambiri, koma palibe mvula yolimba.Alkali-swellable thickening ndi polyurethane amagwiritsidwa ntchito palimodzi, ngakhale kulekanitsa madzi kwenikweni palibe kulekana madzi, koma pambuyo thickening, ndi matope pansi n'zovuta kusonkhezera wogawana.Ndipo womaliza amagwiritsa ntchito pang'ono hydroxyethyl mapadi ndi alkali kutupa ndi polyurethane thickening kukhala yunifolomu boma popanda mpweya ndi kulekana madzi.Zitha kuwoneka kuti mu dongosolo loyera la acrylic emulsion ndi hydrophobicity yamphamvu, ndizovuta kwambiri kukulitsa gawo lamadzi ndi hydrophilic hydroxyethyl cellulose, koma imatha kugwedezeka mosavuta.Kugwiritsiridwa ntchito kamodzi kwa hydrophobic alkali kutupa ndi polyurethane (kapena pawiri) makulidwe, ngakhale ntchito yotsutsana ndi madzi kulekana ndi bwino, koma zonse zimakhuthala pambuyo pake, ndipo ngati pali mvula, imatchedwa mvula yovuta, yomwe imakhala yovuta kugwedeza mofanana.Kugwiritsiridwa ntchito kwa cellulose ndi polyurethane pawiri kukhuthala, chifukwa cha kusiyana kwakukulu kwa hydrophilic ndi lipophilic values, kumabweretsa kulekanitsa kwakukulu kwa madzi ndi mvula, koma matope ndi ofewa komanso osavuta kugwedezeka.Njira yomaliza imakhala ndi ntchito yabwino kwambiri yotsutsana ndi madzi chifukwa cha bwino pakati pa hydrophilic ndi lipophilic.Zoonadi, mu ndondomeko yeniyeni ya mapangidwe, mitundu ya emulsions ndi ma emulsions ndi kunyowetsa ndi dispersing agents ndi makhalidwe awo hydrophilic ndi lipophilic ayeneranso kuganiziridwa.Pokhapokha akafika pamlingo wabwino amatha kukhala mumkhalidwe wa thermodynamic equilibrium ndikukhala ndi madzi abwino kukana.
Mu dongosolo la thickening, kuwonjezereka kwa gawo la madzi nthawi zina kumatsagana ndi kuwonjezeka kwa kukhuthala kwa gawo la mafuta.Mwachitsanzo, timakhulupirira kuti ma cellulose thickeners amakulitsa gawo lamadzi, koma cellulose imagawidwa m'madzi.
Nthawi yotumiza: Dec-29-2022