Polyester resins: ntau lawm thiab tuav

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Nyob rau xyoo tas los no, polyester resins tau nrov heev. Ua ntej ntawm tag nrho cov, lawv nyob rau hauv kev thov raws li cov khoom tseem ceeb thaum lub sij hawm zus tau tej cov fiberglass, muaj zog thiab lub teeb yuag cov ntaub ntawv.

Resin ua: thawj kauj ruam

Yuav ua li cas polyester resin pib? Cov txheej txheem no pib nrog cov roj distillation - lub sijhawm no, ntau yam tshuaj raug tso tawm: benzene, ethylene thiab propylene. Lawv tsim nyog rau zus tau tej cov antihydrides, polybasic acids, glycols. Tom qab ua noj ua haus ua ke, tag nrho cov khoom no tsim lub hauv paus resin, uas nyob rau ntawm ib theem yuav tsum tau diluted nrog styrene. Cov khoom kawg, piv txwv li, tuaj yeem yog 50% ntawm cov khoom tiav. Raws li ib feem ntawm cov theem no, kev muag khoom ntawm cov khoom npaj ua tiav kuj tau tso cai, tab sis cov theem tsim khoom tseem tsis tau tiav: ib qho yuav tsum tsis txhob hnov qab txog saturation nrog ntau yam additives. Nws yog ua tsaug rau cov khoom no uas cov khoom tiav tau txais nws cov khoom tshwj xeeb.

Cov khoom sib xyaw ntawm cov khoom sib xyaw tuaj yeem hloov pauv los ntawm cov chaw tsim khoom - ntau nyob ntawm seb qhov twg siv polyester cob tiag tiag. Cov kws tshaj lij xaiv qhov zoo tshaj plaws kev sib xyaw ua ke, qhov tshwm sim ntawm qhov nokev ua haujlwm yuav yog cov khoom uas muaj cov khoom sib txawv kiag li.

Resin ntau lawm: theem thib ob

Nws yog ib qho tseem ceeb uas cov khoom tiav tiav lawm - feem ntau lawv tos kom txog thaum cov txheej txheem polymerization mus txog qhov kawg. Yog tias nws cuam tshuam, thiab cov khoom muag muag, nws tsuas yog qee qhov polymerized. Yog tias tsis muaj dab tsi ua nrog nws, lub polymerization yuav txuas ntxiv, cov khoom yuav nyuaj. Rau cov laj thawj no, lub txee lub neej ntawm cov resin yog qhov tsawg heev: cov khoom loj dua, nws cov khoom zaum kawg yuav tsis zoo. Polymerization kuj tseem tuaj yeem ua rau qeeb - cov tub yees siv rau qhov no, hardening tsis tshwm sim nyob ntawd.

Yuav kom ua tiav cov theem tsim khoom tiav thiab cov khoom tiav yuav tsum tau, ob yam tseem ceeb yuav tsum tau ntxiv rau cov cob: ib qho catalyst thiab activator. Txhua yam ntawm lawv ua nws tus kheej muaj nuj nqi: lub tshav kub tiam pib nyob rau hauv lub sib tov, uas pab mus rau lub polymerization txheej txheem. Ntawd yog, tsis tas yuav tsum muaj cua sov los ntawm sab nraud - txhua yam tshwm sim yam tsis muaj nws.

Cov txheej txheem ntawm cov txheej txheem polymerization yog tswj hwm - cov kev faib ua feem ntawm cov khoom raug tswj. Txij li thaum kev sib cuag ntawm cov catalyst thiab tus activator tuaj yeem ua rau muaj qhov sib tov sib xyaw, qhov tom kawg yog feem ntau ntxiv rau cov resin nkaus xwb raws li ib feem ntawm cov khoom, cov catalyst yog ntxiv ua ntej siv, nws yog feem ntau muab cais. Tsuas yog thaum cov txheej txheem polymerization tiav, cov khoom ua kom tawv, peb tuaj yeem xaus tias cov khoom ntawm polyester resins tiav.

Original resins

Qhov no yog dab tsicov khoom nyob rau hauv nws thawj lub xeev? Nws yog ib qho zoo li zib ntab, kua nplaum uas muaj peev xwm muaj xim los ntawm tsaus xim av mus rau lub teeb daj. Thaum ib tug npaum li cas ntawm hardeners yog qhia, polyester resin thawj thickens me ntsis, ces kis tau ib tug gelatinous xeev. Ib me ntsis tom qab, qhov sib xws zoo li roj hmab, tom qab ntawd cov khoom tawv tawv (ua rau infusible, insoluble).

txheej txheem no hu ua kho, vim nws yuav siv li ob peb teev ntawm qhov kub thiab txias. Thaum cov resin nyob rau hauv nws cov khoom muaj zog, nws zoo li cov khoom siv tawv tawv, uas tuaj yeem yooj yim dyed nyob rau hauv ntau yam xim. Raws li txoj cai, nws yog siv los ua ke nrog cov iav ntaub (polyester fiberglass), nws ua haujlwm ntawm cov qauv tsim rau kev tsim khoom ntawm ntau yam khoom - xws li polyester resin. Cov lus qhia thaum ua hauj lwm nrog xws li sib tov yog ib qho tseem ceeb heev. Nws yog ib qho tsim nyog ua raws li txhua qhov ntawm nws cov ntsiab lus.

Key nta

Polyester resins hauv lub xeev kho yog cov khoom siv zoo heev. Lawv yog cov yam ntxwv ntawm hardness, siab zog, zoo heev dielectric zog, hnav tsis kam, tshuaj tsis kam. Tsis txhob hnov qab tias nyob rau hauv cov txheej txheem ntawm kev lag luam cov khoom ua los ntawm polyester resin muaj kev nyab xeeb los ntawm ib puag ncig kev pom. Qee yam khoom siv ntawm cov khoom sib xyaw uas siv nrog cov iav ntaub, raws li lawv cov kev ua tau zoo, zoo ib yam li cov khoom siv hlau (qee zaum txawm tshaj lawv). Cov cuab yeej tsim khoom yog pheej yig, yooj yim, nyab xeeb, txij li cov tshuaj kho tau zoo ntawm chav tsev kub.qhov kub thiab txias, txawm tias daim ntawv thov ntawm siab tsis tas yuav tsum tau. Tsis muaj emission ntawm volatile los yog lwm yam by-products, tsuas yog me ntsis shrinkage yog pom. Yog li, txhawm rau tsim cov khoom lag luam, kev tsim khoom kim heev tsis xav tau, thiab tsis tas yuav tsum muaj lub zog thermal, ua tsaug rau cov tuam txhab lag luam sai sai ua kom muaj peev xwm loj thiab muaj peev xwm me me. Tsis txhob hnov qab txog tus nqi qis ntawm polyester resins - daim duab no yog ob zaug qis dua li ntawm epoxy counterparts.

Kev loj hlob

Nws tsis tuaj yeem tsis quav ntsej txog qhov tseeb tias tam sim no kev tsim cov khoom siv tsis zoo polyester tau txais lub zog txhua xyoo - qhov no siv tsis tau rau peb lub teb chaws nkaus xwb, tab sis kuj rau cov qauv txawv teb chaws. Yog tias koj ntseeg qhov kev xav ntawm cov kws tshaj lij, qhov xwm txheej no yeej yuav txuas ntxiv mus rau yav tom ntej.

Disadvantages of resins

Tau kawg, polyester resins kuj muaj qee qhov tsis zoo, zoo li lwm yam khoom siv. Piv txwv li, styrene yog siv los ua cov kuab tshuaj thaum lub sijhawm tsim khoom. Nws yog flammable thiab muaj kuab heev. Tam sim no, xws li cov npe twb tau tsim uas tsis muaj styrene nyob rau hauv lawv muaj pes tsawg leeg. Lwm qhov teeb meem pom tseeb: flammability. Unmodified, unsaturated polyester resins hlawv ib yam li hardwoods. Qhov teeb meem no daws tau: hmoov muab tshuaj yog nkag mus rau hauv cov khoom muaj pes tsawg leeg (tsawg molecular hnyav cov organic tebchaw uas muaj fluorine thiab chlorine, antimony trioxide), qee zaum siv tshuaj hloov kho - tetrachlorophthalic,chlorendic acid, ib co multimers: yas chloroacetate, chlorostyrene, lwm cov tebchaw uas muaj chlorine.

Resin Composition

Yog tias peb xav txog qhov muaj pes tsawg leeg ntawm cov khoom siv tsis zoo polyester, ntawm no peb tuaj yeem nco ntsoov cov khoom sib xyaw ua ke ntawm cov tshuaj sib txawv ntawm cov xwm txheej sib txawv - txhua tus ua haujlwm qee yam. Cov khoom tseem ceeb yog polyester resins, lawv ua haujlwm sib txawv. Piv txwv li, polyester yog cov khoom tseem ceeb. Nws yog ib yam khoom ntawm polycondensation cov tshuaj tiv thaiv ntawm polyols react nrog anhydrides los yog polybasic acids.

Yog tias peb tham txog polyhydric cawv, ces diethylene glycol, ethylene glycol, glycerin, propylene glycol, dipropylene glycol yog xav tau ntawm no. Raws li anhydrides, adipic, fumaric acids, phthalic thiab maleic anhydrides yog siv. Casting ntawm polyester resin yuav tsis yooj yim yog tias polyester muaj qhov hnyav molecular (kwv yees 2000) thaum npaj rau kev ua. Nyob rau hauv cov txheej txheem ntawm molding cov khoom, nws hloov mus rau hauv ib tug polymer nrog ib tug peb-dimensional network qauv, siab molecular hnyav (tom qab curing pib pib). Nws yog cov qauv no uas muab tshuaj tiv thaiv, siab zog ntawm cov khoom.

Solvent-monomer

Lwm yam yuav tsum tau ua yog cov kuab tshuaj monomer. Hauv qhov no, cov kuab tshuaj ua haujlwm dual. Nyob rau hauv thawj rooj plaub, nws yuav tsum tau nyob rau hauv thiaj li yuav txo tau lub viscosity ntawm resin mus rau ib theem uas yuav tsum tau rau kev ua (txij li thaum lub polyester nws tus kheej.tuab heev).

Ntawm qhov tod tes, cov monomer koom nrog hauv cov txheej txheem ntawm copolymerization nrog polyester, vim tias qhov zoo tshaj plaws polymerization ceev thiab qhov tob ntawm cov khoom kho tau raug lees paub (yog tias polyesters raug txiav txim siab cais, lawv kho yog qeeb heev). Hydroperoxide yog qhov tseem ceeb heev uas yuav tsum tau ua kom muaj zog los ntawm lub xeev ua kua - qhov no yog tib txoj kev polyester resin tau txais tag nrho nws cov khoom zoo. Kev siv cov catalyst kuj yog qhov yuav tsum tau ua thaum ua haujlwm nrog cov khoom siv tsis zoo polyester.

Accelerator

Cov khoom xyaw no tuaj yeem ntxiv rau polyesters ob qho tib si thaum tsim khoom thiab thaum ua tiav (ua ntej qhov sib ntxiv ntawm tus pib). Cob alt ntsev (cob alt octoate, naphthenate) tuaj yeem hu ua qhov ua kom zoo tshaj plaws rau kev kho cov polymer. Polymerization yuav tsum tsis tsuas yog ua kom nrawm, tab sis kuj tseem qhib tau, txawm hais tias qee zaum nws qeeb. Qhov tsis pub leejtwg paub yog tias tsis siv cov accelerators thiab cov neeg pib siv, cov dawb radicals yuav ua rau nws tus kheej tsim hauv cov khoom tiav, vim tias cov polymerization yuav tshwm sim ntxov - txoj cai thaum lub sijhawm khaws cia. Txhawm rau tiv thaiv qhov tshwm sim no, kev kho tus mob retarder (inhibitor) yog qhov tseem ceeb.

Inhibitor txoj cai

Lub tswv yim ntawm kev ua ntawm cov khoom no yog raws li hauv qab no: nws cuam tshuam nrog dawb radicals uas tshwm sim ib ntus, ua rau tsim cov radicals qis lossis cov tebchaw uas tsis muaj qhov xwm txheej. Kev ua haujlwm ntawm inhibitors feem ntau yog ua los ntawm xws liCov tshuaj: quinones, tricresol, phenone, qee cov organic acids. Polyesters yog tsim nrog me me ntawm inhibitors thaum lub sij hawm tsim khoom.

Lwm yam ntxiv

Cov khoom tau piav qhia saum toj no yog cov tseem ceeb, nws yog ua tsaug rau lawv tias nws muaj peev xwm ua haujlwm nrog polyester resin ua tus khi. Txawm li cas los xij, raws li kev xyaum qhia, nyob rau hauv tus txheej txheem ntawm kev tsim cov khoom, ib tug txaus loj npaum li cas ntawm additives yog nkag mus rau hauv polyesters, uas, nyob rau hauv lem, nqa tawm ntau yam functions thiab hloov cov yam ntxwv ntawm cov khoom qub. Ntawm cov khoom siv no, cov hmoov ntim tuaj yeem raug sau tseg - lawv tau qhia tshwj xeeb kom txo qis, txo tus nqi ntawm cov khoom, thiab ua kom muaj hluav taws kub. Nws yuav tsum tau muab sau tseg tias iav fabrics (txhim kho cov fillers), kev siv ntawm uas yog vim ib tug nce nyob rau hauv mechanical zog. Muaj lwm yam additives: stabilizers, plasticizers, dyes, thiab lwm yam.

iav mats

Ob lub thickness thiab hauv cov qauv, fiberglass tuaj yeem sib txawv. Cov iav mats yog fiberglass uas tau txiav rau hauv me me, lawv qhov ntev sib txawv ntawm 12-50 mm. Cov ntsiab lus yog glued ua ke siv lwm cov ntaub ntawv ib ntus, uas feem ntau yog hmoov los yog emulsion. Epoxy polyester resin yog siv rau kev tsim cov iav mats, uas muaj cov fibers teem randomly, thaum fiberglass nyob rau hauv nws cov tsos zoo li ib tug zoo tib yam ntaub. Yuav kom ua tiav lub zog siab tshaj plaws, cov qib sib txawv ntawm fiberglass yuav tsum tau siv.

Feem ntau, iav mats muaj tsawg dualub zog, tab sis lawv yooj yim dua rau txheej txheem. Thaum piv nrog fiberglass, cov khoom no zoo dua rov ua cov duab ntawm matrix. Txij li thaum cov fibers luv luv, muaj kev chaotic orientation, lub lev tsis tuaj yeem khav ntawm lub zog loj. Txawm li cas los xij, nws tuaj yeem yooj yim impregnated nrog resin, vim nws yog mos, thaum xoob thiab tuab, me ntsis reminiscent ntawm daim txhuam cev. Cov khoom yog mos thiab moldable tiag tiag. Laminate, piv txwv li, uas yog tsim los ntawm cov lev no, muaj cov khoom siv zoo heev, muaj kev tiv thaiv siab tiv thaiv huab cua (txawm tias nyob rau lub sijhawm ntev).

Qhov twg siv iav mats

Mat yog siv hauv kev sib cuag molding kom tuaj yeem tsim cov khoom nrog cov duab nyuaj. Cov khoom tsim los ntawm cov khoom siv no yog siv rau ntau qhov chaw:

• hauv kev lag luam shipbuilding (tsim canoes, nkoj, yachts, ntses cutters, ntau yam hauv tsev, thiab lwm yam);
• iav lev thiab polyester cob yog siv nyob rau hauv kev lag luam tsheb (ntau yam tshuab qhov chaw, lub tog raj kheej, vans, diffusers, tso tsheb hlau luam, cov ntaub ntawv vaj huam sib luag, vaj tse, thiab lwm yam);
• hauv kev tsim kho kev lag luam (cov khoom siv ntoo, cov tsev tsheb npav, cov phab ntsa, thiab lwm yam).

iav mats muaj qhov sib txawv, nrog rau tuab. Cov khoom muab faib los ntawm qhov hnyav ntawm ib square meter, uas yog ntsuas hauv grams. Muaj ib yam khoom nyias nyias, yuav luagairy (iav daim ntaub thaiv), kuj muaj ib tug tuab, yuav luag zoo li ib daim pam (siv los xyuas kom meej tias cov khoom tau txais cov thickness xav tau, tau txais lub zog yuav tsum tau).