Qhov txawv ntawm urea formaldehyde thiab melamine formaldehyde yog urea formaldehyde yog tsim los ntawm urea thiab formaldehyde monomers, whereas melamine formaldehyde yog tsim los ntawm kev sib xyaw ntawm melamine thiab formaldehyde monomers.
Ob leeg urea formaldehyde thiab melamine formaldehyde yog thermosetting polymers uas tau los ntawm irreversibly hardening (tseem hu ua curing) ib tug mos khoom los yog ib tug viscous kua prepolymer.
YUrea Formaldehyde yog dab tsi?
Urea formaldehyde lossis urea-methanal yog cov thermosetting uas tsis yog pob tshab lossis polymer. Peb tuaj yeem sau nws li UF, thiab nws lub npe hu ua urea formaldehyde vim nws txoj kev sib xyaw ua ke thiab tag nrho cov qauv. Cov resin no yog ib qho tseem ceeb hauv cov nplaum, ua tiav, particleboards, nruab nrab ntom fiberboards, thiab cov khoom pwm.
Lub refractive index ntawm urea formaldehyde yog 1.55. Muaj ob peb yam tseem ceeb ntawm urea formaldehyde uas suav nrog cov hauv qab no:
- High tensile zog
- Flexural modulus
- High heat distortion temperature
- nqus dej tsawg
- Mould shrinkage
- High deg hardness
- Nyob ntawm kev tawg
- Volume resistance
Thaum xav txog cov qauv tshuaj ntawm urea formaldehyde, nws muaj [(O)CNHCH2NH]n ua chav tsev rov ua dua. Feem ntau, cov resin no tshwm sim raws li cov saw polymers tab sis nyob ntawm cov txheej txheem polymerization; muaj peev xwm muaj branched lug thiab. Txhua xyoo, cov tuam txhab tsim tawm txog 20 lab metric tons ntawm UF. Ntau tshaj 70% ntawm qhov kev tsim khoom no yog siv hauv kev lag luam hav zoov-cov khoom lag luam rau kev sib koom ua ke particleboard, MDF hardwood plywood, thiab laminating adhesives.
Daim duab 01: Kev tsim cov urea formaldehyde hauv ob kauj ruam
Cov resin no feem ntau nthuav dav. Muaj ntau ntau yam kev siv ntawm urea-formaldehyde, nrog rau kev tsim cov hniav laminates, textiles, ntawv, foundry xuab zeb moulds, wrinkle-resistant fabrics, paj rwb blends, rayon, thiab lwm yam. Tsis tas li ntawd, muaj ib co kev ua liaj ua teb siv urea-formaldehyde ib yam nkaus., uas suav nrog nws txoj kev siv loj ua qhov tso tawm qeeb ntawm nitrogen. Tsis tas li ntawd, cov resin no yog siv los ua npuas rwb thaiv tsev txij thaum ntxov.
Melamine Formaldehyde yog dab tsi?
Melamine formaldehyde yog ib qho resin muaj melamine rings txiav nrog ntau pawg hydroxyl uas tau muab los ntawm formaldehyde. Nws yog cov khoom siv yas thermosetting uas muaj melamine thiab formaldehyde. Cov khoom siv resin no tau qhia los ntawm William F. Talbot hauv xyoo 1936.
Cov khoom siv cob no tuaj yeem kho tau yooj yim los ntawm cua sov. Ntawm no, lub cev qhuav dej thiab crosslinking tshwm sim. Peb tuaj yeem kho cov melamine-formaldehyde resin lossis monomer ntawm cov khoom siv cob los ntawm kev kho nrog txhua hom polyol.
Daim duab 02: Ib qho Melamine Formaldehyde Phaj
Daim ntawv thov loj ntawm melamine-formaldehyde resin yog tsim cov laminates siab. Cov laminate hom uas peb tuaj yeem tsim siv cov khoom no suav nrog Formica thiab Arborite. Tsis tas li ntawd, peb tuaj yeem siv cov pobzeb phab ntsa panels ntawm no resin li whiteboards. Tsis tas li ntawd, muaj qee qhov kev siv ntawm melamine-formaldehyde resin, nrog rau kev siv cov resin hauv chav ua noj thiab cov phaj. Nws tseem yog ib qho tseem ceeb rau saturating hniav daim ntawv uas yog laminated nyob rau hauv tshav kub thiab siab qhov twg nws yuav yooj yim muab pasted rau particle boards.
Qhov txawv ntawm Urea Formaldehyde thiab Melamine Formaldehyde yog dab tsi?
Urea-formaldehyde thiab melamine formaldehyde yog thermosetting polymers. Urea-formaldehyde los yog urea-methanal yog ib qho uas tsis yog-pob tshab thermosetting resin los yog polymer, whereas melamine formaldehyde yog ib tug resin muaj melamine rings txiav nrog ntau pawg hydroxyl uas tau los ntawm formaldehyde. Qhov sib txawv tseem ceeb ntawm urea formaldehyde thiab melamine formaldehyde yog urea-formaldehyde yog tsim los siv urea thiab formaldehyde monomers whereas melamine formaldehyde yog tsim los ntawm kev sib xyaw ntawm melamine thiab formaldehyde monomers.
Cov lus qhia hauv qab no qhia txog qhov sib txawv ntawm urea formaldehyde thiab melamine formaldehyde hauv daim ntawv tabular.
Summary – Urea Formaldehyde vs Melamine Formaldehyde
Urea-formaldehyde thiab melamine formaldehyde yog thermosetting polymers. Qhov sib txawv tseem ceeb ntawm urea formaldehyde thiab melamine formaldehyde yog urea-formaldehyde yog tsim los ntawm urea thiab formaldehyde monomers thaum melamine formaldehyde yog tsim los ntawm kev sib xyaw ntawm melamine thiab formaldehyde monomers.
