Focus on Cellulose ethers

Cellulose ether na nrapado tile dabere na ciment

1 Okwu mmalite
Nchikota tile nke simenti na-eme ugbu a bụ ngwa kachasị ukwuu nke ngwa ngwa agwakọta akọrọ pụrụ iche, nke bụ ciment mejupụtara dị ka isi cementious ihe na-agbakwunye ya site na mkpokọta graded, ndị na-ejigide mmiri, ndị na-ahụ maka ike mmalite, ntụ ntụ latex na ihe mgbakwunye organic ma ọ bụ inorganic ndị ọzọ. ngwakọta.N'ozuzu, ọ dị mkpa ka a gwakọta ya na mmiri mgbe ejiri ya.E jiri ya tụnyere ụrọ ciment nkịtị, ọ nwere ike imeziwanye ike njikọ dị n'etiti ihe na-eche ihu na mkpụrụ, ma nwee ezigbo nkwụghachi azụ na ezigbo mmiri na mmiri na-eguzogide.Ọ na-tumadi-eji mado ji achọ ihe dị ka ụlọ ime na mputa mgbidi taịl nile, n'ala taịl nile, wdg A na-eji ọtụtụ ebe n'ime ime na mputa mgbidi, ala, ime ụlọ ịwụ, kichin na ndị ọzọ ụlọ mma ebe.Ugbu a ọ bụ ihe njikọ tile kacha eji eme ihe.

Na-emekarị mgbe anyị na-ekpe ikpe na arụmọrụ nke nrapado tile, ọ bụghị nanị na anyị na-aṅa ntị na arụmọrụ arụmọrụ ya na ikike mgbochi, kamakwa ịṅa ntị na ike ọrụ ya na oge mmeghe.Cellulose ether na tile nrapado ọ bụghị naanị na-emetụta rheological Njirimara nke poselin nrapado, dị ka ezigbo ọrụ, ịrapara mma, wdg, ma na-enwe mmetụta siri ike na n'ibu Njirimara nke tile nrapado.

2. Mmetụta na oge mmeghe nke nrapado tile
Mgbe roba ntụ ntụ na cellulose ether na-adị na mmiri mmiri mmiri, ụfọdụ data ụdị na-egosi na roba ntụ ntụ nwere ike kinetic ike itinye na ciment hydration ngwaahịa, na cellulose ether adị ọzọ na interstitial mmiri mmiri, nke na-emetụta ọzọ Mortar viscosity na ịtọ oge.Esemokwu dị n'elu nke cellulose ether dị elu karịa nke ntụ ntụ roba, na ihe ndị ọzọ cellulose ether na-eme ka ọ dịkwuo mma na ngwa ngwa ngwa ga-aba uru maka ịmepụta njikọ nke hydrogen n'etiti ala ala na cellulose ether.

N'ime ngwa agha mmiri mmiri, mmiri dị na ngwa ngwa na-ekpochapụ, na cellulose ether na-eme ka ọ dịkwuo mma n'elu, a ga-emepụta ihe nkiri n'elu ngwa ngwa n'ime nkeji 5, nke ga-ebelata ọnụ ọgụgụ na-esote evaporation, dị ka mmiri ka ukwuu. wepụrụ si thicker ngwa agha Akụkụ nke ya na-akwaga na thinner ngwa agha oyi akwa, na fim e guzobere ná mmalite na- partially etisasịwo, na Mbugharị nke mmiri ga-eme ka ọzọ cellulose ether enrichment na ngwa agha elu.

Ya mere, mmepụta ihe nkiri nke cellulose ether n'elu nke ngwa agha nwere mmetụta dị ukwuu na arụmọrụ nke ngwa agha ahụ.1) Ihe nkiri a kpụrụ akpụ dị oke mkpa ma a ga-agbaze ugboro abụọ, nke na-enweghị ike igbochi evaporation nke mmiri ma belata ike.2) Ihe nkiri a kpụrụ akpụ dị oke oke, ntinye nke cellulose ether na mmiri mmiri interstitial ngwa agha dị elu, na viscosity dị elu, n'ihi ya, ọ dịghị mfe imebi ihe nkiri dị elu mgbe a na-agbanye taịl nile.Enwere ike ịhụ na ihe ndị na-emepụta ihe nkiri nke cellulose ether nwere mmetụta dị ukwuu na oge oghere.Ụdị cellulose ether (HPMC, HEMC, MC, wdg) na ogo nke etherification (nchịkọta nnọchi) na-emetụta kpọmkwem ihe na-emepụta ihe nkiri nke cellulose ether, na ike na ike nke ihe nkiri ahụ.

3. Mmetụta na ike ịbịaru
Na mgbakwunye na inye ihe bara uru ndị a kpọtụrụ aha n'elu na ngwa agha, cellulose ether na-egbukwa oge hydration kinetics nke ciment.Mmetụta a na-eweghachi azụ bụ n'ihi mgbasa nke cellulose ether molecules na usoro ịnweta dị iche iche na simenti na-agba mmiri, ma n'ozuzu n'ikwu okwu, nkwenye bụ na cellulose ether molecules na-abụkarị adsorbed na mmiri dị ka CSH na calcium hydroxide.Na ngwaahịa kemịkalụ, ọ na-adịkarịghị adsorbed na usoro ịnweta nke clinker mbụ.Na mgbakwunye, cellulose ether na-ebelata mmegharị nke ion (Ca2 +, SO42-, ...) na ngwọta pore n'ihi mmụba nke viscosity nke ngwọta pore, si otú ahụ na-egbu oge usoro hydration.

Viscosity bụ ihe ọzọ dị mkpa, nke na-anọchite anya njirimara kemịkalụ nke cellulose ether.Dị ka e kwuru n'elu, viscosity na-emetụtakarị ikike njigide mmiri ma nwee mmetụta dị ukwuu na arụ ọrụ nke ngwa agha ọhụrụ.Otú ọ dị, nchọpụta nnwale achọpụtala na viscosity nke cellulose ether fọrọ nke nta ka ọ bụrụ enweghị mmetụta na ciment hydration kinetics.Ibu molekụla enwechaghị mmetụta na hydration, na oke dị iche n'etiti ịdị arọ molekụla dị iche iche bụ naanị 10min.Ya mere, arọ molekụla abụghị ihe dị mkpa iji chịkwaa hydration ciment.

"Ngwa nke Cellulose Ether na Cement-based Dry-Mixed Mortar Products" gosipụtara n'ụzọ doro anya na nkwụsị nke cellulose ether na-adabere n'ụdị kemịkal ya.Na omume izugbe kwubiri bụ na maka MHEC, ka ogo methylation dị elu, na-ebelata mmetụta nke cellulose ether.Tụkwasị na nke ahụ, mmetụta nkwụsịtụ nke ngbanwe nke hydrophilic (dị ka ngbanwe na HEC) dị ike karịa nke mgbanwe hydrophobic (dị ka ngbanwe na MH, MHEC, MHPC).

N'ime ule ahụ, anyị na-atụle HPMC, nke bụ ngwakọta ether.Maka HPMC, ọ chọrọ ogo nnabata ụfọdụ iji hụ na mmiri solubility ya na nnyefe ọkụ.Anyị maara na ọdịnaya nke substituents na-ekpebi jel okpomọkụ nke HPMC, ya bụ, Ọ na-ekpebi ojiji gburugburu ebe obibi nke HPMC, otú otu ọdịnaya nke HPMC na-emekarị na ọdabara na-emebe n'ime a nso.Na nso nso a, otu esi ejikọta methoxy na hydroxypropoxy iji nweta mmetụta kachasị mma bụ ọdịnaya nke nyocha anyị.N'ime mpaghara ụfọdụ, mmụba nke ọdịnaya nke methoxyl dị iche iche ga-eduga n'ọdịdị ala na ike ndọpụ, ebe mmụba nke ọdịnaya nke otu hydroxypropoxyl ga-eduga n'ịbawanye ike ndọpụ.Enwere mmetụta yiri nke ahụ maka awa mmeghe.
Mgbanwe mgbanwe nke ike n'ibu n'okpuru ọnọdụ oge na-emeghe kwekọrọ na ọnọdụ okpomọkụ nkịtị, nke na-adaberekwa na ike nke cellulose ether film anyị kwuru banyere ya na Nkebi 2. Methoxyl (DS) ọdịnaya dị elu na hydroxypropoxyl. HPMC nwere obere ọdịnaya (MS) nwere ihe siri ike nke ihe nkiri ahụ, mana ọ ga-emetụta wettability nke ngwa agha mmiri na ihe dị n'elu.


Oge nzipu: Jan-30-2023
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