Focus on Cellulose ethers

IiMveliso ze-Ether zeCellulose zokuSebenzisa okuPhezulu kweTele zokuGxisa

Isishwankathelo:

Njengongeziweyo obaluleke kakhulu kwi-adhesives tile, i-cellulose ether inefuthe elinamandla kumandla okudweba kunye nexesha elivulekileyo lokunamathiswa kweetayile, kwaye ezi zinto zimbini zikwangumqondiso obalulekileyo we-adhesives tile adhesives. Iimpembelelo ze-ethers kwiipropati ze-tile adhesives zishwankathelwe kwaye zihlaziywe.

 

Iselulosi ether; Amandla eqhina atsaliweyo; Ixesha lokuvula

 

1. Intshayelelo

Ukunamathiswa kwethayile esekwe kwisamente okwangoku kusesona sicelo sikhulu sodaka olukhethekileyo oluxutyiweyo, oluqulunqwe ngesamente njengeyona nto iphambili yesamente kwaye yongezwa ngamabakala adityanisiweyo, iiarhente zokugcina amanzi, iiarhente zamandla okuqala, umgubo welatex kunye nezinye izongezo zendalo okanye ezingaphiliyo. umxube. Ngokuqhelekileyo, kufuneka ixutywe namanzi kuphela xa isetyenziswa. Xa kuthelekiswa nodaka oluqhelekileyo lwesamente, lunokuphucula kakhulu amandla okudibanisa phakathi kwezinto ezijongene nazo kunye ne-substrate, kwaye inokumelana nokutyibilika okulungileyo kunye nokuchasana kwamanzi kunye namanzi. Isetyenziselwa ikakhulu ukuncamathisela izinto zokuhombisa ezifana nesakhiwo sangaphakathi kunye neetayile zodonga lwangaphandle, iithayile zomgangatho, njl njl. Isetyenziswa ngokubanzi kwiindonga zangaphakathi nangaphandle, imigangatho, amagumbi okuhlambela, amakhitshi kunye nezinye iindawo zokuhombisa izakhiwo. Okwangoku yeyona nto isetyenziswa kakhulu kwiTile bonding material.

 

Ngokuqhelekileyo xa sigweba ukusebenza kwe-adhesive ye-tile, asiyi kuqwalasela kuphela ukusebenza kwayo kunye nekhono lokuchasana ne-sliding, kodwa sinikele ingqalelo kumandla ayo omatshini kunye nexesha lokuvula. I-ether ye-cellulose kwi-adhesive tile ayichaphazeli nje kuphela iimpawu ze-rheological ze-adhesive porcelain, ezifana nokusebenza kakuhle, imela yokunamathela, njl.

 

2. Impembelelo kwixesha elivulekileyo lokunamathela kwi-tile

Xa umgubo werabha kunye neselulosi ether zikho kudaka olumanzi, ezinye iimodeli zedatha zibonisa ukuba umgubo werabha unamandla e-kinetic anamandla okuncamathisela kwimveliso yesamente ye-hydration, kunye ne-cellulose ether ikhona ngakumbi kwi-interstitial fluid, echaphazela ngakumbi i-Mortar viscosity kunye nexesha lokubeka. Uxinzelelo lwangaphezulu lwe-cellulose ether luphezulu kunomgubo werabha, kunye nokutyetyiswa kwe-cellulose ether kwi-interface yodaka kuya kuba luncedo ekubunjweni kweebhondi ze-hydrogen phakathi kwesiseko sesiseko kunye ne-cellulose ether.

 

Kudaka olumanzi, amanzi kumdaka aphuphuma, kwaye i-cellulose ether iyatyetyiswa phezu komhlaba, kwaye ifilimu iya kwenziwa phezu kodaka ngaphakathi kwemizuzu emi-5, eya kunciphisa izinga lokunyuka komphunga, njengoko amanzi amaninzi enziwa. isuswe kudaka olungqindilili Inxalenye yayo ifudukela kumaleko odaka obhityileyo, kwaye ifilimu eyenziwe ekuqaleni ichithwa ngokuyinxenye, kwaye ukufuduka kwamanzi kuya kuzisa ngakumbi ukutyetyiswa kwe-cellulose etere kumphezulu wodaka. Njengoko kubonisiwe kuMfanekiso 1

 

Ngoko ke, ukubunjwa kwefilimu ye-cellulose ether ebusweni bodaka kunempembelelo enkulu ekusebenzeni kodaka. I-1) Ifilimu eyenziwe incinci kwaye iya kuchithwa kabini, engakwazi ukukhawulela ukukhuphuka kwamanzi kunye nokunciphisa amandla. 2) Ifilimu eyenziweyo inzima kakhulu, i-concentration ye-cellulose ether kwi-mortar interstitial liquid iphezulu, i-viscosity iphezulu, kwaye akulula ukuphula ifilimu yomhlaba xa iileyili zifakwe. Ingabonwa ukuba iipropati zokwenza ifilimu ye-cellulose ether inempembelelo enkulu kwixesha elivulekileyo.

 

Uhlobo lwe-cellulose ether (i-HPMC, i-HEMC, i-MC, njl.) kunye ne-degree of etherification (i-substitution degree) ichaphazela ngokuthe ngqo iipropati zefilimu ze-cellulose ether, kunye nobunzima kunye nokuqina kwefilimu.

 

Imo yokufuduka ye-cellulose etere kudaka olumanzi (indawo engaphezulu yithayile ye-ceramic eshinyeneyo, indawo esezantsi isiseko sekhonkrithi enemingxuma)

 

3 Impembelelo kumandla okutsala

Ukongeza ekunikezeni iipropati eziluncedo ezikhankanywe ngasentla kwidaka, i-cellulose ether iphinda ilibazise i-hydration kinetics ye-samente. Esi siphumo sokunciphisa ubukhulu becala kubangelwa ukubhengezwa kweemolekyuli ze-cellulose ether kwizigaba ezahlukeneyo zeminerali kwinkqubo yesamente ifakwe i-hydrated, kodwa ukuthetha ngokubanzi, ukuvumelana kukuba iimolekyuli ze-cellulose ether zibhengezwa kakhulu emanzini afana ne-CSH kunye ne-calcium hydroxide. Kwiimveliso zeekhemikhali, kunqabile ukuba kubhengezwe kwinqanaba lokuqala leminerali ye-clinker. Ukongeza, i-cellulose ether iyanciphisa ukuhamba kwee-ion (Ca2+, SO42-, ...) kwisisombululo se-pore ngenxa yokwanda kwe-viscosity yesisombululo se-pore, ngaloo ndlela ilibazise ngakumbi inkqubo yokufakwa kwamanzi.

 

I-Viscosity yenye iparameter ebalulekileyo, emele iimpawu zekhemikhali ze-cellulose ether. Njengoko kukhankanyiwe ngasentla, i-viscosity ichaphazela kakhulu amandla okugcina amanzi kwaye inefuthe elibalulekileyo ekusebenzeni kodaka olutsha. Nangona kunjalo, uphononongo lovavanyo lufumanise ukuba i-viscosity ye-cellulose ether phantse ayinasiphumo kwi-cement hydration kinetics. Ubunzima bemolekyuli bunempembelelo encinci kwi-hydration, kwaye umahluko omkhulu phakathi kobunzima beemolekyuli ezahlukeneyo yi-10min kuphela. Ke ngoko, ubunzima bemolekyuli abuyiyo iparameter ephambili yokulawula i-cement hydration.

 

Umkhwa oqhelekileyo kukuba kwi-MHEC, iqondo eliphezulu le-methylation, umphumo ongaphantsi kwe-cellulose ether. Ukongezelela, isiphumo sokunciphisa i-hydrophilic substitution (efana nokutshintshwa kwe-HEC) inamandla kunokuba i-hydrophobic substitution (efana nokutshintshwa kwe-MH, i-MHEC, i-MHPC). Isiphumo sokubuyiswa kwe-cellulose ether sichatshazelwa ikakhulu ziiparamitha ezimbini, uhlobo kunye nobuninzi bamaqela abambeleyo.

 

Iimvavanyo zethu ezicwangcisiweyo nazo zafumanisa ukuba umxholo wabaxumi udlala indima ebalulekileyo kumandla omatshini wokunamathela kwi-tile. Sivavanye ukusebenza kwe-HPMC ngamadigri ahlukeneyo okutshintshwa kwi-tile adhesives, kwaye sivavanya umphumo we-cellulose ethers equkethe amaqela ahlukeneyo phantsi kweemeko ezahlukeneyo zokuphilisa kwi-Impembelelo yeepropati ze-mechanical of adhesives tile, i-Figure 2 kunye ne-Figure 3 yimiphumo yotshintsho. kumxholo we-methoxyl (DS) kunye nomxholo we-hydroxypropoxyl (MS) kwiipropati zokukhupha i-adhesive tile kwiqondo lokushisa.

 

Kuvavanyo, siqwalasela i-HPMC, eyi-ether edibeneyo, ngoko ke kufuneka sibeke imifanekiso emibini kunye. Kwi-HPMC, idinga inqanaba elithile lokufunxa ukuqinisekisa ukunyibilika kwayo kwamanzi kunye nokuhanjiswa kokukhanya. Siyawazi umxholo ababambeleyo Kwakhona imisela ijeli lobushushu HPMC, nto leyo emisela nokusingqongileyo ukusetyenziswa HPMC. Ngale ndlela, umxholo weqela le-HPMC odla ngokusebenza ukwakhiwe ngaphakathi koluhlu. Kulo luhlu, indlela yokudibanisa i-methoxy kunye ne-hydroxypropoxy Ukuze ufezekise umphumo ongcono ngumxholo wophando lwethu. Ngaphakathi koluhlu oluthile, ukunyuka kumxholo wamaqela e-methoxyl kuya kukhokelela ekuhlahleni kwamandla okukhupha, ngelixa ukwanda komxholo wamaqela e-hydroxypropoxyl kuya kubangela ukunyuka kwamandla okukhupha. Kukho umphumo ofanayo kwiiyure zokuvula. Impembelelo ye-HPMC enomxholo ohlukeneyo obambeleyo kwiipropati zoomatshini phantsi kwemeko yexesha elivulekileyo lemizuzu engama-20.

 

Utshintsho lwamandla omatshini phantsi kwexesha elivulekileyo lihambelana neqondo lokushisa eliqhelekileyo, elihambelana nokuqina kwefilimu ye-cellulose ether esathetha ngayo kwiCandelo 2. Umxholo we-methoxyl (DS) uphezulu kunye nomxholo. ye-hydroxypropoxyl HPMC enomxholo ophantsi (MS) inokuqina okulungileyo kwefilimu, kodwa iya kuchaphazela ukumanzi kodaka olumanzi kwizinto ezingaphezulu.

 

4 Isishwankathelo

I-cellulose ethers, ngakumbi i-methyl cellulose ethers ezifana ne-HEMC kunye ne-HPMC, izongezo eziyimfuneko kwizicelo ezininzi zodaka oluxubeneyo. Ipropati ebaluleke kakhulu ye-cellulose ethers kukugcinwa kwabo kwamanzi kwizinto zokwakha izimbiwa. Ukuba i-cellulose ether ayifakwanga, umgca omncinci womdaka omtsha uya kumisa ngokukhawuleza, ukwenzela ukuba i-samente ingabi namanzi ngendlela eqhelekileyo, ukwenzela ukuba i-mortar ingakwazi ukuqina kwaye ayikwazi ukufumana iipropati ezintle zokudibanisa kwisiseko. Kukho izinto ezininzi ezichaphazela ukugcinwa kwamanzi kwe-cellulose ether, njenge-dosage kunye ne-viscosity, kunye nokubunjwa kwayo kwangaphakathi: i-degree of substitution inempembelelo enkulu ekusebenzeni kokugqibela komdaka. Kwangexesha elide, sikholelwa ukuba i-viscosity ye-cellulose ether ibalulekile kwizinto ezisekelwe kwi-samente. Ixesha lokumisa isamente linempembelelo enkulu. Uphononongo olutshanje lufumene ukuba utshintsho lwe-viscosity lunempembelelo encinci kwixesha lokubeka i-samente. Ngokuchasene noko, uhlobo kunye nokudityaniswa kwamaqela abambeleyo zezona zinto zibalulekileyo ezichaphazela umsebenzi we-cellulose ether. Xa silindele imveliso yokuncamathelisa ithayile eliphezulu-ukusebenza, asiyi kuphela ukuba sicinge utshintsho rheological impahla eziziswa cellulose ether, leyo eyenza udaka lula ukuphatha, kodwa siqwalasele neziphumo mechanical iimveliso ether cellulose kunye iqondo elifanelekileyo endaweni. negalelo.


Ixesha lokuposa: Feb-09-2023
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