Melamine-formaldehyde resin (MFR) is thermosetting amino resin ine kuoma kwakanaka, kugadzikana kwekupisa, uye kujeka. Kuenzaniswa neurea-formaldehyde resin (UF), MF resin ine mvura inodzivirira zviri nani uye kuramba kwemamiriro ekunze. Nokudaro, inoshandiswa zvakanyanya mumapuranga ekunze ekunze, matanda ekushongedza pasi uye zvigadzirwa zveveneer. Nekudaro, zvikanganiso senge brittleness yakakura, kuputika kuri nyore, uye nguva pfupi yekuchengetedza melamine formaldehyde resin inodzikamisa kushandiswa kwayo. MF resin inowanzo shandiswa kugadzira pepa refirimu rinonamirwa. Plywood uye blockboard yakatarisana neinomisikidzwa inonamira firimu pepa inoungana inonzi ecological board. Vanodiwa nevatengi nekuda kwekusapfeka kwavo, kusapinda kwemvura, uye mavara akasiyana.
Nekudaro, kana hunyoro hwezvakatipoteredza huchichinja, iyo ecological board base zvinhu zvinowanzozvimba kana kuderera, zvichikonzera kusagadzikana kwemukati. Iyo yekumusoro layer yeMF resin ine brittle uye haina kuchinjika, uye inogara ichitsemuka nekushushikana. Naizvozvo, kuvandudza kuchinjika kweMF resin uye kuvandudza brittleness dambudziko ndiwo makiyi ekugadzirisa dambudziko rekutsemuka resin uye kuvandudza kunaka kwezvigadzirwa zvayo zvekushongedza. Ichi chinyorwa chinonyanya kupfupisa kufambira mberi kwekutsvagisa pamusoro pekuomesa gadziriso yeMF resin, nechinangwa chekupa gwara redzidziso uye tekinoroji hwaro hwekugadzirisa dambudziko rekusagadzikana kweMF resin.
1. MF maitiro maitiro
MF resin inonzi triazine ring polymer compound inoumbwa ne condensation ye melamine uye formaldehyde uye yakabatanidzwa ne methylene kana ether bond. Iine chimiro chemakemikari yakagadzikana uye chimiro chakasimba. Kuumbwa kweMF resin kwakakamurwa kuita nhanho mbiri: yekutanga nhanho ndeyekuwedzera maitiro e melamine uye formaldehyde. Pasi pemamiriro asina kwaakarerekera kana ealkaline, melamine inopinda hydroxymethylation kugadzira 9 dzakasiyana hydroxymethylmelamines. Danho rechipiri ndeye condensation reaction. Melamine inopindirana ne methylolated melamine, kana methylolated melamine inopinda self-condensation kugadzira oligomers akabatana nemethylene uye ether bond. Munharaunda ine pH kukosha kwe7 kusvika ku8, methylene bridge connections inotonga; munzvimbo ine pH inodarika 9, ether bond connections inowanzoita.
Mushure mekuyambuka-kubatanidza uye kurapa kweMF resin, yakajeka yakapetwa isingapfeki, asidhi uye alkali inodzivirira inogona kuwanikwa. Kunyangwe iyo yakarapirwa yakapetwa ine yakanyanya kuoma, zvakare ine brittle. Chikonzero chikuru ndechekuti MF resin ine nhamba yakawanda yezvindori zve triazine zvakabatana nemapoka emethylene. Mhete dze triazine dzakasimba zvakanyanya pasi pemamiriro ekunze uye inonetsa kutsveyamisa uye kutora simba rekuita. Chete methylene bonds inogona kutora yakawanda yesimba, zvichiita kuti methylene bond atyoke uye kuratidza brittleness. Kurapwa kusina kukwana kweMF resin kunokonzera kuparuka kweresin. Sezvo kurapa resin kuchinyanya kuitika pakati pemapoka ehydroxyl, mamwe mapoka ehydroxyl asina kutora chikamu mukukonyesa acharamba ari muresin mushure mekurapa. Aya mapoka ehydroxyl ane imwe hygroscopicity. Sezvo hunyoro hwezvakatipoteredza huchichinja kakawanda, mapoka emahara ehydroxyl achaita hygroscopic uye desorption cycles uye zvishoma nezvishoma anounza kushushikana, zvichikonzera kutsemuka mukuputira resin uye kukanganisa zvakanyanya kutaridzika uye kuita kwechigadzirwa.
Iko kuchinjika kweMF resin kunogona kunyatso kuvandudzwa nekudzikisa muchinjiko wekubatanidza density yeMF resin uye nekuwedzera yayo inochinjika cheni kureba. Zvisinei, kuderedzwa kwe-cross-linking density kunoreva kuti chimiro chakasimba chemhete ye triazine mu resin inoparadzirwa. Naizvozvo, kusimba kwepamusoro uye kupfeka kuramba kweMF resin kuchakanganiswa kune akasiyana madhigirii. Paunenge uchiita kuomesera shanduko, kutarisirwa kunofanirwa kutorwa kuchengetedza kuomarara kweMF resin uye kusaparadza yakanakisa nzvimbo yepasi. Kusarudza nzira yakakodzera yekushandura yekuvandudza kuchinjika kweMF resin kwakakosha zvikuru mukuwedzera huwandu hwekushandisa kweMF resin.
2. Toughening shanduko nzira yeMF resin
Toughening gadziriso inowanzo shandiswa kukwidziridza kusimba kweakaomarara-akabatanidzwa mapolymers kuvandudza kukanganiswa kwemaitiro uye kuneta kuramba kwepolymer pasina kuparadza kuomarara kwepakutanga uye kugadzikana kwedimensional yepolymer. Toughening gadziriso nzira dzakakodzera MF resin inogona kupatsanurwa kuita mhando mbiri, dzinoti yekunze toughening shanduko uye yemukati toughening shanduko. External toughening modification inoreva kuwedzera kusimbaradza mapoka echikamu kuMF resin kuburikidza nekubatanidza kuita muchinjiko wakabatana chimiro neMF resin kudzivirira mhete dzetriazine kuswedera kune imwe neimwe kuzadzikisa chinangwa chekuomesa. Inowanzo shandiswa kunze kwekuomesera nzira dzeMF resin dzinosanganisira:
1) Wedzera nano-SiO2, nano-cellulose uye mamwe nanoparticles;
2) Shandisa flexible long-chain polymers se polyethylene glycol copolymers kuti uite interpenetrating polymer network (IPNS) muMF resin;
3) Shandisa fiber zvinhu zvakaita sepolyvinyl chloride kubatanidza MF resin pamwechete kuti uwedzere kugadzikana kweiyo resin chimiro.
Internal toughening modification inoshandura mamolecular chimiro cheMF resin nekutora chikamu mukurapa maitiro eMF resin, kuwedzera flexible connection pakati pe triazine rings, uye kuderedza kuyambuka-linking density kuti ibudirire. Nzira dzekudzivirira mukati dzinosanganisira:
1) Isai anochinjika marefu-cheni mamorekuru pakati pe triazine mhete zvimiro zveMF resin kuparadzira iyo yakasimba chimiro;
2) Shandisa silicone kuti uwedzere kuwirirana kunoshanduka pakati peMF resins;
3) Vhara iyo hydroxyl inoshanda boka reMF resin uye kuderedza kuyambuka-inobatanidza density yeresin. Inowanzo shandiswa mukati toughening modifiers inosanganisira polyvinyl doro, polyurethane, caprolactam, nezvimwe.
3. Special zvinodiwa kuti MF resin kuti impregnation
Kune nzira dzakawanda dzekuomesera dzeMF resin, asi hadzisi dzese dzakakodzera kuitisa MF resin. Iko kuomesera kugadziridzwa kwekuisa pamuviri weMF resin kunofanirwa kuenderana nemamiriro ekugadzirwa kwepepa rinonamira firimu, saka rine zvimwe zvakakosha zvinodiwa. Paunenge uchishandisa MF resin yekupfekedza, isu hatifanirwe kungofunga nezve kutsemuka kuramba, kupfeka kuramba uye kuchinjika mushure mekurapa resin, asi zvakare teerera kune fluidity, permeability uye pre-kurapa dhigirii resin yakagadziridzwa isati yapora.
Iyo yakashata fluidity yeMF resin inokonzeresa maruva akaoma pamusoro peiyo impregnated adhesive film paper veneer, ichiburitsa opaque machena machena pamusoro pechigadzirwa, ichigadzira pamusoro pezvikanganiso. Kusakwana kwe MF resin kunokonzeresa kusakwana, zvichikonzera kushaikwa kweglue kana kusaenzana pamusoro pechigadzirwa. Inorganic nano-wear-resistant zvinhu zvinogona kuwedzera kuomarara uye kusapfeka-resistant zvimiro zveMF resin, asi panguva imwe chete ivo vanozowedzera viscosity yeMF resin uye kuderedza fluidity yeresin, nekudaro kukanganisa kusamira kweMF resin. Takaona kuti viscosity yeMF resin inowedzera nekuwedzera kwehuwandu hwekupfeka-resistant filler nano-SiO2 (HTSi-03). Iyo viscosity yeiyo yakagadziridzwa MF resin system yaive 20.9 s (25 ° C), uye iyo yekuonana angle pakati peMF resin uye pepa rekushongedza yakawedzera kubva ku5 ° kusvika 30 °. Panguva imwecheteyo, kunyorova kunoderera, kuitira kuti MF resin haigoni kuzadza zvakakwana zviputi mumapepa ekushongedza, uye kupfeka-kusagadzikana kwekuvhara hakugoni kudzivirira zvakakwana, zvichiita kuti kuderera kwekuremara kwekupfeka.
Iyo yakaderera pre-kupora degree yeMF resin inokonzeresa kuvhuvhuta kwakanyanya panguva yeveneer process, zvichiita kuti maruva akanyorova epamusoro akanganisa kushanda kwepasi. Polyhydroxyl alcohol modifiers inogona kunyatso wedzera kuchinjika kweMF resin, asi imwe hydrophilicity yepolyhydroxyl modifiers haikodzeri kuomeswa kwepepa rekunamira firimu remufirimu, nekudaro ichideredza pre-popa degree reMF resin. Izvi zvinokonzeresa matambudziko akadai sekunyudzwa kwemwando uye kunamira kwepepa refirimu rekunamira rakaiswa uye kunetsa kuwana. Panguva imwecheteyo, iyo yakanamirwa firimu firimu pepa rine yakaderera pre-kupora dhigirii inoburitsa yakawanda yemvura panguva yekupisa yekutsikirira, zvichikonzera matambudziko senge vhoriyamu shrinkage yeadhesive layer uye kuputika kweresin layer, zvichikanganisa kuita kwechigadzirwa.
Naizvozvo, tichitarisa iwo chaiwo matambudziko ekugadzira, iyo MF resin toughening agent inoshandiswa kumisa pamuviri inofanirwa kushandisa modifier ine yakaderera molecular huremu, yakaderera hydroxyl zvemukati, uye yakakwirira reactivity kuderedza kukanganiswa kweiyo modifier pane fluidity uye pre-kuporesa degree reMF resin. Panguva imwecheteyo, mumiriri anoomesera anodiwa kuti ajairane nemamiriro ekurapa eMF resin inoshandiswa kupinza, uye achiramba achigadzirisa maitiro mushure mekupisa kupisa kupora.
Kugadziriswa kweMF resin yekumisikidza kunoda kufunga zvakawanda zvinhu panguva imwe chete. Iyo yakanakira modifier inosimudzira kuchinjika kweMF resin pasina kukanganisa pamusoro kupfeka kuramba, fluidity kana pre-kurapa maitiro. Nokudaro, zvinokurudzirwa kuti tsvakurudzo yeramangwana pamusoro pekushandurwa kweMF resin inofanira kuitwa kubva kune zvitatu zvinotevera.
1) Zvichienderana nechimiro cheMF resin, iyo brittleness dambudziko reMF resin rinogona kugadziriswa nekugadzirisa iyo cross-linking density yeMF resin.
2) Kubatanidza nzira dzakasiyana dzekuomesa, suma chinjika cheni chimiro nemapoka-anoshanda akawanda muMF resin, uye kuwedzera kuchinjika kweMF resin kuburikidza nekubatana kwekubatanidzwa kwemuviri uye kuita kwemakemikari.
3) Kubva pamaonero ekurerutsa maitiro ekugadzira uye kuchengetedza mari, sarudza yakanyanya reactive modifiers inokodzera kugadzirwa kwemaindasitiri.
Ruzivo rwakawanda nezve SINOYQX modified melamine formaldehyde resin, ndapota taura nesu kuburikidza neemail: [email protected] , kana kutitaurira panhamba iyi: +86-28-8411-1861.
Mimwe mifananidzo uye zvinyorwa zvinoburitswa kubva paInternet, uye kodzero yacho ndeyemunyori wekutanga. Kana paine chero kukanganisa, ndapota taura nesu kuti tibvise.