Yuav Ua Li Cas Thiaj Ua Tau Polymethyl Methacrylate Yas Thiab Nws Daim Ntawv Thov Hauv Acrylic
Polymethyl methacrylate (PMMA) yog ib hom yas engineering uas nrov heev thiab paub dav los ntawm cov npe lag luam xws li "acrylic," "plexiglass," lossis "acrylic glass." Cov khoom no feem ntau raug xaiv los ua iav hloov vim nws yog pob tshab, sib dua, muaj zog dua, thiab muaj kev nyab xeeb dua li iav vim nws tsis yooj yim tawg ua tej daim ntse. Tom qab nws qhov tsos yooj yim, PMMA yog qhov tshwm sim ntawm cov txheej txheem tshuaj polymerization tswj hwm, pib los ntawm monomer methyl methacrylate (MMA). Tsab xov xwm no tham txog yuav ua li cas PMMA feem ntau ua hauv kev lag luam, cov kauj ruam tseem ceeb koom nrog, thiab nws cov ntawv thov hauv ntau yam khoom acrylic.
Kawm Paub Txog PMMA: Ib Lub Yas Ntshiab Uas Muaj Ntau Lub Hom Phiaj
PMMA yog ib hom thermoplastic polymer uas muaj qhov pom tseeb zoo, tiv taus huab cua (UV thiab av noo), thiab ruaj khov zoo. Nws qhov tsis zoo suav nrog nws qhov kev cuam tshuam rau kev khawb piv rau iav thiab nws lub peev xwm tawg hauv qee qhov kev poob siab. Txawm li cas los xij, nws cov khoom ua rau PMMA zoo rau cov ntawv thov pob tshab, zoo nkauj uas xav tau kev ruaj khov sab nraum zoov.
Hauv kev tsim kho, PMMA yog tsim los ntawm cov chav rov ua dua los ntawm kev sib xyaw ua ke ntawm methyl methacrylate (MMA) monomers. Cov txheej txheem ntawm kev hloov cov kua monomers mus rau hauv cov khoom polymers khov kho tuaj yeem ua tiav siv ntau txoj hauv kev, nyob ntawm seb cov khoom kawg xav tau: daim ntawv, pas nrig, kav dej, lossis pellets rau kev txhaj tshuaj / molding.
Cov Khoom Siv Raw Tseem Ceeb: MMA Monomer thiab Initiator
Cov khoom xyaw tseem ceeb rau kev tsim PMMA yog MMA monomer, uas yog cov kua ntshiab, tsis yooj yim tawg, thiab yooj yim hlawv. Rau MMA los tsim cov saw polymer, yuav tsum muaj cov tshuaj pib dawb - ib yam khoom uas "pib" qhov kev sib xyaw polymerization -. Cov tshuaj pib feem ntau tham txog hauv cov ntsiab lus kev lag luam suav nrog cov organic peroxides lossis azo compounds. Tsis tas li ntawd, nyob ntawm cov khoom kawg ntawm lub hom phiaj, cov txheej txheem yuav suav nrog:
1. Tus neeg sawv cev tswj/hloov pauv saw hlau los tswj qhov ntev ntawm cov saw hlau polymer (cuam tshuam rau viscosity, lub zog, thiab kev ua haujlwm tau).
2. Cov tshuaj stabilizer los tiv thaiv kev ua polymerization ntxov thaum lub sijhawm khaws cia monomer thiab pab kom cov khoom ruaj khov.
3. Cov tshuaj ntxiv xws li cov xim zas, cov tshuaj nqus UV, lossis cov tshuaj hloov pauv yog tias koj xav ua kom tawv dua.
Yuav tsum nco ntsoov tias hauv kev lag luam, kev tsim cov tshuaj thiab kev tswj cov txheej txheem yog nruj heev vim tias MMA polymerization reaction yog exothermic (tsim cua sov). Kev tswj tsis raug tuaj yeem ua rau muaj npuas, qhov tsis zoo ntawm qhov muag, lossis txawm tias muaj kev phom sij rau kev nyab xeeb.
Txoj Cai Tseem Ceeb: Kev Ua Polymerization Dawb Radical
Feem ntau, PMMA tsim tawm siv cov dawb radical polymerization, uas muaj peb theem tshuaj tiv thaiv:
1. Kev Pib: Tus neeg pib lwj (piv txwv li vim yog cua sov) tsim cov free radicals.
2. Kev nthuav dav: Cov free radicals ua rau muaj kev cuam tshuam nrog MMA monomers thiab pib txoj kev loj hlob ntawm cov saw polymer.
3. Kev xaus: Kev loj hlob ntawm cov saw hlau nres vim tias ob lub radicals sib ntsib, lossis vim yog lwm txoj hauv kev xws li kev hloov pauv ntawm cov saw hlau.
Kev tswj qhov kub thiab txias, lub sijhawm teb, thiab cov khoom sib xyaw yog qhov tseem ceeb rau PMMA zoo. Rau cov ntawv thov kho qhov muag xws li cov ntawv ntshiab, lub hom phiaj tseem ceeb yog kom txo cov npuas, cov huab, thiab cov khoom tsis sib xws.
Txoj Kev Siv Dav Dav ntawm PMMA Kev Tsim Khoom
Feem ntau hais lus, muaj ntau txoj hauv kev tseem ceeb uas kev lag luam siv los tsim PMMA. Kev xaiv txoj kev cuam tshuam rau qhov meej, tus nqi, qhov ceev ntawm kev tsim khoom, thiab cov duab kawg ntawm cov khoom.
1) Kev Ua Polymerization Ntau
Hauv txoj kev no, MMA monomer yog polymerized tsis muaj cov kuab tshuaj (lossis hauv cov khoom me me). Nws cov txiaj ntsig suav nrog kev ntshiab siab thiab kev pom tseeb zoo heev, ua rau nws feem ntau siv rau cov khoom siv acrylic cam khwb cia. Txawm li cas los xij, vim tias qhov tshuaj tiv thaiv yog exothermic heev thiab viscosity nce siab thaum qhov tshuaj tiv thaiv nce mus, kev tswj cua sov yog qhov nyuaj heev.
Yuav ua cov ntawv acrylic cam khwb cia, monomer nrog lub initiator raug nchuav rau hauv ib lub pwm tiaj tus (feem ntau yog muab tais rau ntawm ob lub phaj iav nrog gaskets los txiav txim siab qhov tuab), tom qab ntawd maj mam cua sov hauv qhov cub. Qhov kev cua sov maj mam no yog qhov tseem ceeb kom tiv thaiv kev tsim cov npuas thiab kev ntxhov siab sab hauv. Tom qab polymerization tiav lawm, daim ntawv maj mam txias (annealed) kom txo cov kev ntxhov siab seem thiab ua kom daim ntawv ruaj khov.
Feem ntau cov acrylic uas ua los ntawm cam khwb cia muaj qhov pom tseeb siab, tiv taus huab cua zoo dua, thiab yooj yim rau txhuam, ua rau nws siv dav rau cov khoom tso saib zoo, cov thoob dej loj, thiab cov ntawv thov kho qhov muag.
2) Kev ncua polymerization
Hauv txoj kev ncua, MMA raug faib ua cov tee dej me me hauv dej siv tus neeg sawv cev ncua, tom qab ntawd polymerized los ua cov hlaws dai. Cov hlaws dai ces qhuav thiab tuaj yeem yaj lossis ua tiav ntxiv rau hauv cov pellets rau extrusion lossis txhaj tshuaj.
Qhov zoo ntawm txoj kev no suav nrog kev txias yooj yim dua (dej pab nqus cua sov), thiab cov khoom granular yog qhov tsim nyog rau kev tsim khoom loj. Txoj kev no yog ib txwm muaj rau kev tsim cov khoom siv PMMA raw uas yuav raug ua tiav rau hauv ntau yam khoom siv siv cov extruders lossis cov tshuab txhaj tshuaj molding.
3) Kev ua kom cov kua polymerization
Ntawm no, MMA yog polymerized hauv cov organic solvent. Kev tswj cua sov zoo dua li kev ua ntau, tab sis cov txheej txheem xav tau ib kauj ruam sib cais cov kuab tshuaj, uas ntxiv tus nqi thiab qhov nyuaj. Txoj kev no feem ntau siv rau cov ntawv thov tshwj xeeb xws li kev tsim cov PMMA-based resins lossis coatings.
4) Kev sib xyaw ua ke ntawm cov khoom siv emulsion
Txoj kev emulsion siv cov surfactants thiab dej los tsim cov polymer latex. Qhov no yog ib txwm muaj rau qee cov acrylic polymers hauv cov xim lossis cov txheej txheem, txawm hais tias rau PMMA ntshiab (acrylic iav), emulsions tsis yog qhov kev xaiv zoo tshaj plaws vim muaj kev sib tw ua kom huv thiab meej. Txawm li cas los xij, lub tswv yim emulsion tseem ceeb hauv tsev neeg acrylic polymer tag nrho.
Cov Theem Tsim Khoom Acrylic (Daim Ntawv, Qws, thiab Lwm Yam Duab)
Thaum PMMA raug tsim, cov khoom siv tuaj yeem ua tiav rau hauv cov khoom acrylic los ntawm ntau txoj hauv kev tseem ceeb:
1. Casting (Cor): Tsim cov ntawv acrylic cam khwb cia nrog cov khoom siv kho qhov muag zoo.
2. Kev Rho Tawm: PMMA raug yaj thiab tom qab ntawd raug yuam los ntawm lub pwm kom tsim cov ntawv extruded, pas nrig, yeeb nkab, lossis profile. Cov ntawv extruded feem ntau pheej yig dua thiab muaj kev kam rau siab dua, tab sis kev tiv taus cov kuab tshuaj thiab kev ntxhov siab tawg tuaj yeem txawv ntawm kev pov.
3. Kev Txhaj Tshuaj Moulding: Rau cov khoom sib xyaw xws li cov iav yooj yim, lub hau, lub pob qhov rooj, thiab cov khoom siv hluav taws xob, yuav tsum tswj qhov kub thiab txias zoo thiab tsim pwm kom tiv thaiv cov cim ntws lossis cov kev ntxhov siab seem.
Rau cov ntawv thov zaum kawg, PMMA tuaj yeem txiav laser, drilled, bent nrog cua sov, glued nrog cov cement tshwj xeeb, thiab polished kom rov qab tau qhov tseeb ntawm ntug.
Cov Ntawv Thov PMMA hauv Cov Khoom Acrylic
PMMA siv dav vim nws ua ke ntawm kev zoo nkauj, pob tshab, thiab kev tiv taus huab cua.
1) Cov Khoom Siv Iav Hloov: Qhov Rai, Qhov Rooj Saum Ntuj, thiab Cov Ntaub Thaiv Pob Zeb
PMMA feem ntau siv ua cov vaj huam sib luag pob tshab rau cov tshuab tiv thaiv, cov khoom faib, lossis cov ntaub thaiv uas xav tau kev pom kev. Hauv kev tsim vaj tsev, acrylic siv rau hauv cov qhov rais saum ru tsev, cov ntaub thaiv hnub, thiab cov khoom dai kom zoo nkauj, feem ntau vim nws sib dua li iav thiab tiv taus UV.
2) Kev Tso Tawm thiab Cov Paib Qhia
Cov ntawv acrylic yooj yim txiav thiab kos, suav nrog siv lasers, ua rau lawv nrov rau cov paib, cov thawv neon, cov khoom tso saib hauv khw, cov thav duab, thiab cov rooj muag khoom tshaj tawm. PMMA kuj tseem siv tau nrog kev luam ntawv thiab lamination.
3) Optics thiab Teeb Pom Kev Zoo
Vim nws qhov pom tseeb zoo heev, PMMA siv rau cov khoom siv diffusers, cov vaj huam sib luag qhia teeb (LGPs), cov ntaub thaiv teeb, thiab qee yam khoom siv kho qhov muag. Hauv qee qhov kev tsim, PMMA raug xaiv vim nws txoj kev xa lub teeb zoo heev thiab muaj peev xwm ua micro-textured los tswj kev faib lub teeb.
4) Tsheb thiab Kev Thauj Mus Los
PMMA siv rau hauv cov ntaub thaiv teeb taub hau, cov vaj huam sib luag sab hauv, thiab cov khoom dai kom zoo nkauj. Kev tiv taus huab cua yog qhov zoo, txawm hais tias cov polycarbonate hloov kho lossis PMMA qee zaum siv rau kev tiv taus kev cuam tshuam siab.
5) Kev Kho Mob thiab Kev Kho Hniav
PMMA tau siv ntev hauv kev kho hniav (piv txwv li, cov hauv paus hniav cuav) thiab qee yam kev siv kho mob, vim nws tuaj yeem ua kom ruaj khov thiab sib haum xeeb rau qee yam kev siv. Txawm li cas los xij, cov qauv kho mob yog nruj heev, thiab cov txheej txheem txawv ntawm kev tsim khoom dav dav.
6) Aquarium thiab Tuab Qauv
Cov acrylic tuab feem ntau siv rau cov vaj huam sib luag loj hauv thoob dej yug ntses thiab cov qhov rai saib xyuas vim tias nws tuaj yeem tsim cov tuab siab thaum tswj tau qhov pom tseeb zoo. Ntxiv mus, PMMA tuaj yeem txhuam kom nws pom tseeb.
Kev kaw
PMMA, lossis acrylic, yog ib hom yas uas tsim los ntawm kev sib xyaw ua ke ntawm MMA monomers, feem ntau yog los ntawm cov txheej txheem dawb-radical. Cov txheej txheem tsim khoom xws li bulk, suspension, solution, thiab emulsion raug xaiv raws li cov khoom xav tau thiab zoo. Rau cov ntawv thov acrylic ntshiab, casting feem ntau nyiam vim nws qhov pom tseeb zoo heev thiab qhov zoo ntawm qhov chaw. Lub caij no, extrusion thiab txhaj tshuaj molding txhawb nqa kev tsim khoom ntau dua.
Nrog nws txoj kev sib xyaw ua ke ntawm kev pom tseeb, kev tiv taus huab cua, thiab kev ywj pheej ntawm cov txheej txheem, PMMA tseem yog cov khoom siv tseem ceeb rau cov paib, cov khoom tso saib, teeb pom kev zoo, kev tsim vaj tsev, thiab lwm yam kev siv tshuab. Kev nkag siab txog seb PMMA ua li cas pab peb nkag siab txog qhov sib txawv ntawm qhov zoo ntawm cov acrylic cam khwb cia thiab extruded, thiab yuav ua li cas xaiv hom acrylic zoo rau kev siv txhua hnub thiab kev lag luam.
