Melamine-formaldehyde resin (MFR) yog ib hom thermosetting amino resin uas muaj qhov nyuaj zoo, thermal stability, thiab pob tshab. Piv nrog urea-formaldehyde resin (UF), MF resin muaj dej tsis kam zoo dua thiab huab cua tsis kam. Yog li ntawd, nws yog siv dav hauv cov txheej txheem sab nraum zoov, cov ntoo hauv pem teb kho kom zoo nkauj thiab cov khoom veneer. Txawm li cas los xij, qhov tsis zoo xws li brittleness siab, yooj yim tawg, thiab lub sijhawm khaws cia luv luv ntawm melamine formaldehyde resin txwv nws daim ntawv thov. MF resin feem ntau yog siv los npaj cov ntawv nplaum impregnated. Plywood thiab blockboard ntsib nrog cov ntawv nplaum impregnated yog hu ua ecological boards. Lawv nyiam los ntawm cov neeg siv khoom vim lawv qhov kev tiv thaiv hnav, dej tsis kam, thiab ntau yam xim.
Txawm li cas los xij, thaum cov av noo ib puag ncig hloov pauv, cov khoom siv hauv paus ntawm lub rooj tsavxwm ecological yuav o lossis ntsws, ua rau muaj kev ntxhov siab sab hauv tsis sib xws. Txheej saum npoo ntawm MF resin yog brittle thiab tsis muaj kev ywj pheej, thiab nws yooj yim tawg thaum muaj kev ntxhov siab. Yog li ntawd, kev txhim kho kev ywj pheej ntawm MF resin thiab kev txhim kho nws qhov teeb meem brittleness yog qhov tseem ceeb rau kev daws teeb meem ntawm resin tawg thiab txhim kho qhov zoo ntawm nws cov khoom dai kom zoo nkauj. Tsab xov xwm no feem ntau yog sau luv luv txog kev nce qib ntawm kev tshawb fawb ntawm kev hloov kho toughening ntawm MF resin, nrog rau kev muab kev taw qhia theoretical thiab lub hauv paus kev siv rau kev daws teeb meem brittleness ntawm MF resin.
1. Cov yam ntxwv ntawm MF
MF resin yog ib qho tshuaj polymer uas tsim los ntawm kev sib xyaw ntawm melamine thiab formaldehyde thiab txuas nrog methylene lossis ether bonds. Nws muaj cov khoom siv tshuaj ruaj khov thiab cov qauv khov kho. Kev tsim cov MF resin muab faib ua ob theem: theem thawj zaug yog qhov sib ntxiv ntawm melamine thiab formaldehyde. Nyob rau hauv cov xwm txheej nruab nrab lossis alkaline, melamine dhau los ntawm hydroxymethylation los tsim 9 hydroxymethylmelamines sib txawv. Theem thib ob yog qhov sib xyaw ua ke. Melamine reacts nrog methylolated melamine, lossis methylolated melamine dhau los ntawm kev sib xyaw ua ke los tsim cov oligomers txuas nrog methylene thiab ether bonds. Hauv ib puag ncig nrog pH tus nqi ntawm 7 txog 8, kev sib txuas methylene choj dominate; hauv ib puag ncig nrog pH tus nqi siab dua 9, kev sib txuas ether bond yuav tsim tau ntau dua.
Tom qab kev sib txuas thiab kho ntawm MF resin, ib txheej pob tshab uas tsis yooj yim hnav, tiv taus kua qaub thiab alkali tuaj yeem tau txais. Txawm hais tias txheej kho muaj qhov nyuaj siab, nws kuj tseem tawg yooj yim. Qhov laj thawj tseem ceeb yog tias MF resin muaj ntau lub nplhaib triazine txuas nrog methylene pawg. Cov nplhaib triazine ruaj khov heev nyob rau hauv cov xwm txheej cuam tshuam thiab nyuaj rau deform thiab nqus cov zog cuam tshuam. Tsuas yog methylene bonds tuaj yeem nqus feem ntau ntawm lub zog, ua rau cov methylene bonds tawg thiab ua rau pom kev tawg. Kev kho tsis tiav ntawm MF resin yuav ua rau cov resin tawg. Txij li thaum cov resin kho feem ntau tshwm sim ntawm cov pab pawg hydroxyl, qee cov pab pawg hydroxyl uas tsis tau koom nrog hauv condensation yuav nyob hauv cov resin tom qab kho. Cov pab pawg hydroxyl no muaj qee qhov hygroscopicity. Raws li qhov av noo ib puag ncig hloov pauv ntau zaus, cov pab pawg hydroxyl dawb yuav dhau los ntawm hygroscopic thiab desorption voj voog thiab maj mam tsim kev ntxhov siab, ua rau muaj kev tawg hauv cov txheej resin thiab cuam tshuam loj heev rau qhov tsos thiab kev ua tau zoo ntawm cov khoom.
Qhov yooj ywm ntawm MF resin tuaj yeem txhim kho tau zoo los ntawm kev txo qhov sib txuas ntawm MF resin thiab txuas nws cov saw ntev. Txawm li cas los xij, qhov txo qis ntawm qhov sib txuas ntawm qhov sib txuas txhais tau tias cov qauv khov kho ntawm lub nplhaib triazine hauv cov resin tau tawg. Yog li ntawd, qhov tawv ntawm qhov chaw thiab kev hnav tsis kam ntawm MF resin yuav raug cuam tshuam rau ntau qib. Thaum ua qhov kev hloov kho tawv, yuav tsum tau ceev faj kom tswj tau qhov tawv ntawm MF resin thiab tsis txhob rhuav tshem nws cov khoom zoo heev ntawm qhov chaw. Kev xaiv txoj kev hloov kho kom haum los txhim kho qhov yooj ywm ntawm MF resin yog qhov tseem ceeb heev rau kev nthuav dav ntawm daim ntawv thov ntawm MF resin.
2. Txoj kev hloov kho kom tawv ntawm MF resin
Kev hloov kho toughening feem ntau yog siv los ua kom lub zog ntawm cov polymers sib txuas khov kho kom zoo dua qub kom txhim kho qhov kev tiv thaiv kev cuam tshuam thiab kev qaug zog ntawm cov polymer yam tsis rhuav tshem qhov qub toughness thiab qhov ntev ntawm cov polymer. Cov txheej txheem hloov kho toughening uas haum rau MF resin feem ntau tuaj yeem muab faib ua ob hom, uas yog kev hloov kho toughening sab nraud thiab kev hloov kho toughening sab hauv. Kev hloov kho toughening sab nraud yog hais txog kev ntxiv cov pab pawg theem txhawb nqa rau MF resin los ntawm kev sib xyaw ua ke los tsim cov qauv sib txuas nrog MF resin kom tiv thaiv cov nplhaib triazine los ntawm kev sib cuag kom ua tiav lub hom phiaj ntawm kev toughening. Cov txheej txheem toughening sab nraud uas siv ntau rau MF resin suav nrog:
1) Ntxiv nano-SiO2, nano-cellulose thiab lwm yam nanoparticles;
2) Siv cov polymers ntev uas yoog tau xws li polyethylene glycol copolymers los tsim cov interpenetrating polymer networks (IPNS) hauv MF resin;
3) Siv cov ntaub ntawv fiber xws li polyvinyl chloride los txuas MF resins ua ke kom txhim kho kev ruaj khov ntawm cov qauv resin.
Kev hloov kho sab hauv toughening hloov cov qauv molecular ntawm MF resin los ntawm kev koom nrog hauv cov tshuaj kho ntawm MF resin, txuas ntxiv qhov kev sib txuas yooj ywm ntawm cov nplhaib triazine, thiab txo qhov sib txuas ntawm qhov sib txuas kom ua tiav cov nyhuv toughening. Cov txheej txheem ntawm kev toughening sab hauv suav nrog:
1) Qhia cov molecules ntev-saw yooj ywm ntawm cov qauv triazine nplhaib ntawm MF resin kom tawg cov qauv nruj;
2) Siv silicone los txuas qhov kev sib txuas ntawm MF resins;
3) Thaiv cov hydroxyl functional pawg ntawm MF resin thiab txo qhov sib txuas ntawm cov resin. Cov khoom siv sab hauv toughening modifiers feem ntau suav nrog polyvinyl cawv, polyurethane, caprolactam, thiab lwm yam.
3. Cov kev cai tshwj xeeb rau MF resin rau impregnation
Muaj ntau txoj kev ua kom tawv rau MF resin, tab sis tsis yog txhua tus ntawm lawv haum rau impregnating MF resin. Kev hloov kho tawv ntawm impregnating MF resin yuav tsum hloov kho rau cov xwm txheej tsim khoom ntawm cov ntawv nplaum zaj duab xis, yog li nws muaj qee qhov kev cai tshwj xeeb. Thaum siv MF resin rau impregnation, peb yuav tsum tsis txhob tsuas yog xav txog qhov tawg tsis kam, hnav tsis kam thiab yooj ywm tom qab kho cov resin, tab sis kuj yuav tsum them sai sai rau qhov fluidity, permeability thiab pre-curing degree ntawm cov hloov kho resin ua ntej kho.
Qhov tsis zoo ntawm MF resin yuav ua rau cov paj qhuav ntawm qhov chaw ntawm cov ntawv nplaum impregnated, tsim cov pob dawb opaque ntawm qhov chaw ntawm cov khoom, tsim cov qhov tsis zoo ntawm qhov chaw. Qhov tsis zoo permeability ntawm MF resin yuav ua rau tsis txaus impregnation, ua rau tsis muaj kua nplaum lossis qhov chaw tsis sib xws ntawm qhov chaw ntawm cov khoom. Cov ntaub ntawv inorganic nano-wear-resistant tuaj yeem ua rau muaj zog thiab hnav-resistant zog ntawm MF resin, tab sis tib lub sijhawm lawv yuav ua rau kom muaj viscosity ntawm MF resin thiab txo qhov fluidity ntawm resin, yog li cuam tshuam rau kev ua haujlwm impregnation ntawm MF resin. Peb pom tias qhov viscosity ntawm MF resin nce nrog qhov nce ntawm cov khoom siv hnav-resistant filler nano-SiO2 (HTSi-03). Qhov viscosity ntawm cov hloov kho MF resin system yog 20.9 s (25 ° C), thiab lub kaum sab xis ntawm MF resin thiab daim ntawv kho kom zoo nkauj nce ntxiv los ntawm 5 ° txog 30 °. Tib lub sijhawm, qhov ntub dej txo qis, yog li ntawd MF resin tsis tuaj yeem sau cov qhov sib txawv hauv daim ntawv kho kom zoo nkauj, thiab cov txheej tiv thaiv hnav tsis tuaj yeem tiv thaiv nws tag nrho, ua rau txo qis kev hnav tsis kam.
Qhov degree qis ua ntej kho ntawm MF resin yuav ua rau muaj kev hloov pauv siab thaum lub sijhawm ua veneer, ua rau cov paj ntub dej ntawm qhov chaw cuam tshuam rau kev ua haujlwm ntawm qhov chaw. Cov tshuaj hloov kho cawv polyhydroxyl tuaj yeem ua rau qhov yooj ywm ntawm MF resin zoo dua, tab sis qhov hydrophilicity ntawm polyhydroxyl modifiers tsis zoo rau kev ziab ntawm cov ntawv nplaum impregnated, yog li txo qhov degree ua ntej kho ntawm MF resin. Qhov no ua rau muaj teeb meem xws li kev nqus dej noo thiab kev nplaum ntawm cov ntawv nplaum impregnated thiab nyuaj rau nkag mus. Tib lub sijhawm, cov ntawv nplaum impregnated nrog degree qis ua ntej kho yuav tso tawm ntau cov dej thaum lub sijhawm kub nias, ua rau muaj teeb meem xws li ntim ntawm cov txheej nplaum thiab tawg ntawm cov txheej resin, cuam tshuam rau kev ua haujlwm ntawm cov khoom.
Yog li ntawd, xav txog qhov teeb meem tiag tiag ntawm kev tsim khoom, tus neeg sawv cev MF resin toughening siv rau impregnation yuav tsum siv cov khoom hloov kho nrog qhov hnyav molecular qis, cov ntsiab lus hydroxyl qis, thiab cov tshuaj tiv thaiv siab kom txo qhov cuam tshuam ntawm cov khoom hloov kho rau qhov fluidity thiab pre-curing degree ntawm MF resin. Tib lub sijhawm, tus neeg sawv cev toughening yuav tsum tau hloov kho rau cov xwm txheej kho ntawm MF resin siv rau impregnation, thiab tseem tswj tau qhov hloov kho tom qab kub nias kho.
Kev hloov kho ntawm MF resin rau impregnation yuav tsum xav txog ntau yam tib lub sijhawm. Tus modifier zoo tagnrho yuav txhim kho qhov yooj ywm ntawm MF resin yam tsis muaj kev cuam tshuam tsis zoo rau qhov hnav tsis kam, fluidity lossis pre-curing txheej txheem. Yog li ntawd, nws raug pom zoo tias kev tshawb fawb yav tom ntej ntawm kev hloov kho ntawm MF resin yuav tsum tau ua los ntawm peb yam hauv qab no.
1) Raws li cov qauv ntawm MF resin, qhov teeb meem brittleness ntawm MF resin tuaj yeem daws tau los ntawm kev kho qhov sib txuas ntawm MF resin.
2) Ua ke ntau yam txheej txheem tawv, qhia txog cov qauv saw hlau uas muaj ntau pawg ua haujlwm rau hauv MF resin, thiab ua kom MF resin yooj ywm dua los ntawm kev sib koom ua ke ntawm kev sib xyaw ua ke thiab kev tshuaj lom neeg.
3) Los ntawm qhov kev xav ntawm kev ua kom yooj yim rau cov txheej txheem ntau lawm thiab txuag cov nqi, xaiv cov kev hloov pauv uas muaj zog heev uas tsim nyog rau kev tsim khoom lag luam.
Xav paub ntxiv txog SINOYQX hloov kho melamine formaldehyde resin, thov hu rau peb ntawm email: [email protected] , lossis hu rau peb ntawm: + 86-28-8411-1861.
Qee cov duab thiab cov ntawv luam tawm los ntawm Is Taws Nem, thiab cov ntawv pov thawj yog los ntawm tus sau thawj. Yog tias muaj kev ua txhaum cai, thov hu rau peb kom tshem tawm.