I-Melamine-formaldehyde resin (MFR) yintlaka ye-amino ebeka i-thermosetting enobunzima obuhle, ukuzinza kwe-thermal, kunye nokungafihli. Xa kuthelekiswa ne-urea-formaldehyde resin (UF), i-resin ye-MF inokumelana namanzi okungcono kunye nokumelana nemozulu. Ngoko ke, isetyenziswe ngokubanzi kwiingubo zepaneli zangaphandle, umgangatho womthi wokuhlobisa umgangatho kunye neemveliso ze-veneer. Nangona kunjalo, iintsilelo ezinje ngokuqina okuphezulu, ukuqhekeka ngokulula, kunye nexesha elifutshane lokugcina i-melamine formaldehyde resin kunciphisa ukusetyenziswa kwayo. I-resin ye-MF isoloko isetyenziselwa ukulungiselela iphepha lefilimu elinamathelayo elifakwe ngaphakathi. I-Plywood kunye ne-blockboard ejongene nephepha lefilimu elinamathelayo elifakwe ngokudibeneyo libizwa ngokuba ziibhodi ze-ecological. Ziyathandwa ngabathengi ngenxa yokungagugi, ukungangeni kwamanzi, kunye nemibala eyahlukeneyo.
Nangona kunjalo, xa ubume bendalo buguquka, isiseko sebhodi yendalo sithande ukudumba okanye ukucutheka, okukhokelela kuxinzelelo olungalinganiyo lwangaphakathi. Umaleko womphezulu we-MF resin unobuqhophololo kwaye une-flexibility embi, kwaye uthambekele ekuqhekekeni phantsi koxinzelelo. Ngoko ke, ukuphucula ukuguquguquka kwe-MF resin kunye nokuphucula ingxaki ye-brittleness yizitshixo zokusombulula ingxaki yokuqhekeka kwe-resin kunye nokuphucula umgangatho weemveliso zayo zokuhombisa. Eli nqaku ikakhulu lishwankathela inkqubela yophando malunga nokuguqulwa kokuqina kwe-MF resin, ngenjongo yokubonelela ngesikhokelo sethiyori kunye nesiseko sobugcisa sokusombulula ingxaki ye-brittleness ye-MF resin.
1. Iimpawu zesakhiwo seMF
I-MF resin yi-triazine ring polymer compound eyenziwe yi-condensation ye-melamine kunye ne-formaldehyde kwaye idibene ne-methylene okanye i-ether bonds. Ineempawu ezizinzileyo zeekhemikhali kunye nesakhiwo esiqinileyo. Ukuqulunqwa kwe-resin ye-MF kwahlulwe ngamanqanaba amabini: isigaba sokuqala kukusabela okongeziweyo kwe-melamine kunye ne-formaldehyde. Ngaphantsi kweemeko ezingathathi hlangothi okanye ze-alkaline, i-melamine idlula i-hydroxymethylation ukuvelisa i-9 eyahlukeneyo ye-hydroxymethylmelamines. Inqanaba lesibini kukusabela kwe-condensation. I-Melamine iphendula kunye ne-methylolated melamine, okanye i-methylolated melamine idlula i-self-condensation ukuze ivelise i-oligomers exhunywe yi-methylene kunye ne-ether bond. Kwindawo enexabiso le-pH ye-7 ukuya kwi-8, uxhulumaniso lwebhulorho ye-methylene lulawula; kwindawo enexabiso le-pH elingaphezulu kwe-9, uxhulumaniso lwebhondi ye-ether kunokwenzeka ukuba yenze.
Emva kokudibanisa kunye nokunyangwa kwe-resin ye-MF, i-coat transparent e-resistant-resistant, i-asidi kunye ne-alkali enganyangekiyo inokufumaneka. Nangona i-coat enyangisiweyo inobunzima obuphezulu, ibuye ibe brittle. Isizathu esona sizathu kukuba i-resin ye-MF iqulethe inani elikhulu lamakhonkco e-triazine adibene namaqela e-methylene. Iringi ze-triazine zizinzile kakhulu phantsi kweemeko zempembelelo kwaye kunzima ukuguqula nokufunxa amandla empembelelo. Iibhondi ze-methylene kuphela ezinokufunxa amandla amaninzi, okubangela ukuba iibhondi ze-methylene ziphuke kwaye zibonise i-brittleness. Ukunyangwa okungaphelelanga kwe-MF resin kuya kubangela ukuqhekeka kwe-resin. Kuba ukunyangwa kwe-resin kwenzeka ikakhulu phakathi kwamaqela e-hydroxyl, amanye amaqela e-hydroxyl angakhange athathe nxaxheba kwi-condensation aya kuhlala kwi-resin emva kokunyanga. La maqela e-hydroxyl ane-hygroscopicity ethile. Njengoko ukufuma kokusingqongileyo kutshintsha ngokuphindaphindiweyo, amaqela e-hydroxyl asimahla aya kutyhutyha imijikelo ye-hygroscopic kunye ne-desorption kwaye ngokuthe ngcembe avelise uxinzelelo, okubangela ukuqhekeka kwi-resin coating kwaye kuchaphazele kakhulu inkangeleko kunye nokusebenza kwemveliso.
Ukuguquguquka kwe-resin ye-MF kunokuphuculwa ngokufanelekileyo ngokunciphisa ukuxinana kwe-cross-linking ye-MF resin kunye nokwandisa ubude bayo obuguquguqukayo bekhonkco. Nangona kunjalo, ukuncitshiswa kwe-cross-linking density kuthetha ukuba ulwakhiwo oluqinileyo lwendandatho ye-triazine kwi-resin iyahlakazeka. Ke ngoko, ukuqina komphezulu kunye nokumelana nokunxiba kwe-MF resin kuya kuchaphazeleka kwiidigri ezahlukeneyo. Xa usenza ukuguqulwa kokuqina, kufuneka kuthathelwe ingqalelo ukugcina ubulukhuni be-MF resin kwaye ungabhubhisi iipropati zayo ezintle kakhulu. Ukukhetha indlela efanelekileyo yokuguqula ukuphucula ukuguquguquka kwe-MF resin kubaluleke kakhulu ekwandiseni umda wesicelo se-MF resin.
2. Indlela yokuguqula i-toughening ye-MF resin
Ukuguqulwa kwe-toughening ngokuqhelekileyo kusetyenziselwa ukwandisa amandla eepolima ezinqamlezileyo ezinqamlezileyo ukuphucula ukuxhathisa impembelelo kunye nokumelana nokudinwa kwepolymer ngaphandle kokutshabalalisa ukuqina koqobo kunye nokuzinza kwe-dimensional ye-polymer. Iindlela zokuguqula i-toughening ezifanelekileyo kwi-resin ye-MF zinokwahlulwa ngokubanzi zibe ziindidi ezimbini, ezizezi, ukuguqulwa kokuqina kwangaphandle kunye nokuguqulwa kokuqina kwangaphakathi. Ukuguqulwa kwangaphandle kwe-toughening kubhekiselele ekongezeni amaqela esigaba sokuqinisa kwi-resin ye-MF ngokuxuba ukwenza i-cross-linked structure kunye ne-MF resin ukukhusela amakhonkco e-triazine ukuba asondelane ukuze afezekise injongo yokuqina. Iindlela eziqhelekileyo ezisetyenziswayo zangaphandle zokuqina kwi-MF resin ziquka:
1) Yongeza i-nano-SiO2, i-nano-cellulose kunye nezinye i-nanoparticles;
2) Sebenzisa iipolymers eziguquguqukayo ze-long-chain ezifana ne-polyethylene glycol copolymers ukwenza i-interpenetrating polymer networks (IPNS) kwi-resin ye-MF;
I-3) Sebenzisa izinto zefiber ezifana ne-polyvinyl chloride ukudibanisa i-MF resins kunye nokuphucula ukuzinza kwesakhiwo se-resin.
Ukuguqulwa kwangaphakathi kwe-toughening kutshintsha i-molecular structure ye-MF resin ngokuthatha inxaxheba kwi-resin yokuphilisa ye-MF resin, ukwandisa uxhulumaniso oluguquguqukayo phakathi kwamakhonkco e-triazine, kunye nokunciphisa ukuxinana kwe-cross-linking density toughening effect. Iindlela zokuqinisa ngaphakathi ziquka:
I-1) Yazisa iimolekyuli eziguquguqukayo ze-long-chain phakathi kwezakhiwo ze-triazine ring ye-MF resin ukusabalalisa isakhiwo esiqinileyo;
2) Sebenzisa i-silicone ukwandisa uxhulumaniso oluguquguqukayo phakathi kwee-resin ze-MF;
I-3) Vimba iqela elisebenzayo le-hydroxyl le-MF resin kwaye unciphise ukuxinana kwe-cross-linking of resin. Iimodyuli ezisetyenziswa ngokuqhelekileyo zangaphakathi zibandakanya i-polyvinyl alcohol, i-polyurethane, i-caprolactam, njl.
3. Iimfuno ezizodwa ze-MF resin for impregnation
Zininzi iindlela eziqinisayo ze-MF resin, kodwa ayizizo zonke ezilungele ukumitha i-resin ye-MF. Ukuguqulwa kwe-toughening ye-resin ye-MF yokukhulelwa kufuneka ihambelane neemeko zokuveliswa kwephepha lefilimu yokunamathela, ngoko ke ineemfuno ezithile ezikhethekileyo. Xa kusetyenziswa i-resin ye-MF yokukhulelwa, akufanele sicinge kuphela ukuchasana nokuqhekeka, ukunyanzeliswa kokugqoka kunye nokuguquguquka emva kokunyangwa kwe-resin, kodwa sinikele ingqalelo kumanzi, ukunyanzeliswa kunye ne-pre-curing degree ye-resin eguquliweyo ngaphambi kokunyanga.
Ukungaphumeleli kwe-resin ye-MF kuya kubangela iintyatyambo ezomileyo kumphezulu we-adhesive film paper veneer edibeneyo, evelisa amabala amhlophe opaque kumphezulu wemveliso, okwenza iziphene. Ukungena kakuhle kwe-resin ye-MF kuya kubangela ukungabikho ngokwaneleyo, okubangela ukungabikho kweglue okanye indawo engalinganiyo kwindawo yemveliso. I-inorganic nano-wear-resistant materials inokunyusa ukuqina kunye neempawu ezixhatshazwayo ze-MF resin, kodwa kwangaxeshanye ziya kwandisa i-viscosity ye-MF resin kwaye zinciphise umbane we-resin, ngaloo ndlela zichaphazela ukusebenza kwe-MF resin. Sifumene ukuba i-viscosity ye-MF resin iyanda ngokunyuka kwenani le-filler-resistant filler nano-SiO2 (HTSi-03). I-viscosity yenkqubo ye-resin ye-MF elungisiweyo yayiyi-20.9 s (25 ° C), kwaye i-angle yoqhagamshelwano phakathi kwe-resin ye-MF kunye nephepha lokuhlobisa lenyuke ukusuka kwi-5 ° ukuya kwi-30 °. Ngelo xesha, ukumanzisa kuyancipha, ukwenzela ukuba i-resin ye-MF ingakwazi ukuzalisa ngokupheleleyo izikhewu kwiphepha lokuhlobisa, kwaye i-coat-resistant-resistant coating ayikwazi ukuyikhusela ngokupheleleyo, okubangelwa ukuhla kokuxhatshazwa kokugqoka.
Iqondo eliphantsi lokunyanga kwangaphambili le-MF resin liya kubangela ukuguquguquka okuphezulu ngexesha lenkqubo ye-veneer, okubangela ukuba iintyatyambo ezimanzi zichaphazele ukusebenza komphezulu. I-polyhydroxyl alcohol modifiers inokunyusa ngokufanelekileyo ukuguquguquka kwe-MF resin, kodwa i-hydrophilicity ethile ye-polyhydroxyl modifiers ayihambisani nokomisa iphepha lefilimu elincamathelayo elifakwe ngaphakathi, ngokunciphisa iqondo lokunyanga kwangaphambili kwe-resin ye-MF. Oku kubangela iingxaki ezifana nokufunxa umswakama kunye nokubambelela kwephepha lefilimu elinamathelayo elifakwe ngaphakathi kunye nobunzima bokufikelela. Ngelo xesha, iphepha lefilimu elinamathele elifakwe kwi-degree ephantsi yokunyanga kwangaphambili liya kukhupha inani elikhulu lamanzi ngexesha loxinzelelo olushushu, olubangela iingxaki ezifana nokunciphisa umthamo we-adhesive layer kunye nokuqhekeka kwe-resin layer, echaphazela ukusebenza kwemveliso.
Ke ngoko, kuqwalaselwe ezona ngxaki zemveliso, i-agent ye-MF resin toughening agent esetyenziselwa ukukhulelwa kufuneka isebenzise isilungisi esinobunzima obuphantsi bemolekyuli, umxholo ophantsi we-hydroxyl, kunye nokuphinda kusebenze okuphezulu ukunciphisa impembelelo yesilungisi kwi-fluidity kunye ne-pre-curing degree ye-resin ye-MF. Ngelo xesha, i-agent enzima iyadingeka ukuba ihambelane neemeko zokuphilisa i-MF resin esetyenziselwa ukukhulelwa, kwaye igcine umphumo wokuguqulwa emva kokunyanzeliswa koxinzelelo olushushu.
Ukuguqulwa kwe-resin ye-MF yokukhulelwa kufuneka kuthathelwe ingqalelo izinto ezininzi ngexesha elinye. Isilungisi esifanelekileyo siya kuphucula ukuguquguquka kwe-MF resin ngaphandle kokuchaphazela kakubi ukuxhathisa kokunxiba komphezulu, ulwelo okanye inkqubo yokunyanga kwangaphambili. Ngoko ke, kucetyiswa ukuba uphando lwexesha elizayo malunga nokuguqulwa kwe-MF resin kufuneka lwenziwe kule miba mithathu ilandelayo.
I-1) Ngokusekelwe kwisakhiwo se-MF resin, ingxaki ye-brittleness ye-MF resin ingasombululwa ngokulungelelanisa ukuxinana kwe-cross-linking ye-MF resin.
I-2) Ukudibanisa iindlela ezahlukeneyo zokuqina, ukwazisa i-flexible chain structure kunye namaqela amaninzi asebenzayo kwi-resin ye-MF, kunye nokwandisa ukuguquguquka kwe-resin ye-MF ngokusebenzisa i-synergy yokudibanisa ngokomzimba kunye nokuphendula kweekhemikhali.
3) Ukusuka kumbono wokwenza lula inkqubo yokuvelisa kunye nokugcina iindleko, khetha iimodyuli ezisebenzayo kakhulu ezifanelekileyo kwimveliso yeshishini.
Ulwazi oluthe kratya malunga ne-SINOYQX modified melamine formaldehyde resin, nceda unxibelelane nathi nge-imeyile: [email protected] , okanye usithumelele umyalezo ku: +86-28-8411-1861.
Eminye imifanekiso kunye nezicatshulwa zenziwe kwakhona kwi-Intanethi, kwaye i-copyright yeyombhali wokuqala. Ukuba kukho naluphi na ulwaphulo-mthetho, nceda uqhagamshelane nathi ukuze ucime.