Aqoonta Agabka Baakadaha - Maxaa Sababa Isbedelka Midabka Alaabta Caaga ah?

• Waxyeellada oksaydhka ee alaabta ceeriin waxay keeni kartaa midab marka la qaabeynayo heerkulka sare;
• Midabaynta midabaynta heerkulka sare waxay keeni doontaa midabaynta alaabta caagga ah;
• Falcelinta kiimikaad ee udhaxeysa midabka iyo alaabta ceeriin ama waxyaabaha lagu daro waxay keeni doontaa midab;
• Dareen-celinta u dhaxaysa waxyaabaha lagu daro iyo oksaydhka tooska ah ee waxyaabaha lagu daro waxay keeni doontaa isbeddel midab;
• Tautomerization ee midabaynta midabaynta hoos yimaada ficilka iftiinka iyo kulaylka waxay keeni doontaa isbeddelka midabka alaabta;
• Wasakhowga hawada ayaa laga yaabaa inay isbeddel ku keento badeecooyinka balaastikada ah.

1. Waxa Sababay Qalabaynta Caaga ah

1) Nabaad-guurka oksaydhka ee alaabta ceeriin waxay keeni kartaa midab marka la qaabeeyo heerkul sare

Marka giraanta kuleyliyaha ama saxanka kuleyliyaha qalabka wax lagu hagaajiyo ee caagga ah uu had iyo jeer ku jiro xaalad kuleyl ah sababtoo ah xakameynta ka baxsan, way fududahay in ay keento heerkulka maxalliga ah inuu aad u sarreeyo, taas oo ka dhigaysa alaabta ceeriin oxidize iyo barar heerkulka sare. Wixii caagadaha kulaylka leh, sida PVC, way fududahay in Marka dhacdadani dhacdo, marka ay halis tahay, way guban doontaa oo waxay isu rogi doontaa jaalle, ama xitaa madow, oo ay la socoto qadar badan oo ah volatiles molecular hooseeya oo buuxdhaafaya.

Hoosudhacaan waxaa ka mid ah falcelinta sidaDepolymerization, maqas silsilad random, ka saarida kooxaha dhinaca iyo walxaha miisaanka kelli oo hooseeya.

• Depolymerization

Dareen-celinta dillaaca waxay ku dhacdaa isku xirka silsiladda terminaalka, taasoo keenaysa isku xirka silsiladda inuu mid mid u dhaco, monomer-ka la soo saarayna si degdeg ah ayuu u kacsan yahay. Waqtigan xaadirka ah, miisaanka kelliku si tartiib ah ayuu isu beddelaa, sida habka rogaal celinta silsiladda polymerization. Sida depolymerization kulaylka ee methyl methacrylate.

• Qalitaanka Silsiladda Random (Degradation)

Waxa kale oo loo yaqaannaa jebinta random ama silsilado jabay random. Marka la eego ficilka xoogga farsamada, shucaaca tamarta sare, mowjadaha ultrasonic ama reagents kiimikaad, silsiladda polymer-ka ayaa jebisa iyada oo aan lahayn meel go'an si loo soo saaro polymer miisaan-yar oo miisaan leh. Waa mid ka mid ah siyaabaha hoos u dhaca polymer-ka. Marka silsiladda polymer-ka ay hoos u dhigto si aan kala sooc lahayn, miisaanka kelliku si degdeg ah ayuu hoos ugu dhacayaa, miisaanka luminta polymerka waa mid aad u yar. Tusaale ahaan, habka xaalufinta ee polyetylen, polyene iyo polystyrene ayaa inta badan ah nabaad-guurka random.

Marka polymers-ka sida PE lagu qaabeeyo heerkul sare, meel kasta oo silsiladda ugu weyn ayaa laga yaabaa in la jebiyo, miisaanka molecular hoos u dhaco si degdeg ah, laakiin dhalidda monomer waa mid aad u yar. Dareen-celinta noocan oo kale ah waxaa loo yaqaanaa qalalka silsiladda random, mararka qaarkood waxaa loo yaqaan deradation, polyethylene Xagjirrada xorta ah ee la sameeyay ka dib markii silsiladda la gooyo ayaa aad u firfircoon, oo ay ku hareereysan yihiin hydrogen sare oo dheeraad ah, u nugul falcelinta wareejinta silsiladda, ku dhawaadna lama soo saarin monomers.

• Ka saarida beddelka

PVC, PVAc, iwm. waxay mari karaan falcelinta ka saarista beddelka ah marka la kululeeyo, sidaas darteed taagga ayaa badanaa ka muuqda qalooca heerkulbeegga. Marka polyvinyl chloride, polyvinyl acetate, polyacrylonitrile, polyvinyl fluoride, iwm. la kululeeyo, bedelaadaha waa laga saarayaa. Qaadashada polyvinyl chloride (PVC) tusaale ahaan, PVC waxaa lagu farsameeyaa heerkul ka hooseeya 180 ~ 200 ° C, laakiin heerkul hoose (sida 100 ~ 120 ° C), waxay bilaabataa inay fuuqbaxdo (HCl), waxayna luminaysaa HCl aad u badan. si degdeg ah oo ku saabsan 200 ° C. Sidaa darteed, inta lagu jiro farsamaynta (180-200 ° C), polymer-ku wuxuu u eg yahay inuu noqdo midab madow oo hoos u dhigaya xoogga.

HCl lacag la'aana waxay saameyn ku leedahay fuuq-baxa, iyo chlorides biraha, sida ferric chloride oo ay sameeyeen ficilka hydrogen chloride iyo qalabaynta, waxay kor u qaadaan catalysis.

Dhowr boqolkiiba nuugista aashitada, sida barium stearate, organotin, xeryahooda rasaasta, iwm, waa in lagu daraa PVC inta lagu jiro habaynta kuleylka si loo hagaajiyo xasilloonida.

Marka fiilada isgaadhsiinta loo isticmaalo midabaynta fiilada isgaadhsiinta, haddii lakabka polyolefin ee fiilada naxaasta ah aanu xasilloonayn, karboksylate naxaasta cagaaran ayaa lagu samayn doonaa interface polymer-copper. Dareen-celintani waxay kor u qaaddaa faafinta naxaasta ee polymer-ka, iyaga oo dardargelinaya oksaydhka naxaasta ah.

Sidaa darteed, si loo yareeyo heerka xaalufka oksaydhiyaha ee polyolefins, phenolic ama aromatic amine antioxidants (AH) ayaa inta badan lagu daraa si loo joojiyo falcelinta kor ku xusan oo ay sameeyaan xag-jiryo xor ah oo aan firfircoonayn A ·: ROO·+AH-→ROOH+A·

• Hoosudhaca Oxidative

Alaabooyinka polimer-ka ah ee hawada soo gala waxay nuugaan ogsijiinta waxayna maraan oksaydheynta si ay u sameeyaan hydroperoxides, waxay sii burburaan si ay u abuuraan xarumo firfircoon, waxay sameeyaan xagjirnimo bilaash ah, ka dibna waxay maraan falcelinta silsiladda xagjirka ah ee bilaashka ah (ie, habka auto-oxidation). Polymers waxay la kulmaan ogsijiinta hawada inta lagu jiro habaynta iyo isticmaalka, iyo marka la kululeeyo, xaalufka oksaydhisku waa la dedejiyaa.

oksaydhka kulaylka ee polyolefins waxaa iska leh habka falcelinta silsiladda xagjirka ah ee xorta ah, kaas oo leh dabeecad autocatalytic waxaana loo qaybin karaa saddex tallaabo: bilawga, koritaanka iyo joojinta.

Maqaarka silsiladda ee ay sababaan kooxda hydroperoxide waxay keentaa hoos u dhaca miisaanka kelli, iyo wax soo saarka ugu muhiimsan ee maqasku waa khamriga, aldehydes, iyo ketones, kuwaas oo ugu dambeyntii oksaydhiyay ilaa asiidhyada karboksilic. Asiidhyada Carboxylic waxay door weyn ka ciyaaraan oksaydhka kicinta ee biraha. Nabaad-guurka Oxidative waa sababta ugu weyn ee sii xumaanaya sifooyinka jireed iyo farsamada ee alaabta polymer. Burburinta Oxidative waxay ku kala duwan tahay qaabka molecular ee polymerka. Joogitaanka oksijiinta waxay sidoo kale xoojin kartaa dhaawaca iftiinka, kulaylka, shucaaca iyo xoogga farsamada ee polymers, taasoo keenaysa falcelin-xumo aad u adag. Antioxidants ayaa lagu daraa polymers si loo yareeyo xaalufka oksaydhiyeyaasha.

2) Marka balaastiga la farsameeyo oo la qaabeeyo, midabku wuu qudhmi, wuu qallalaa oo midabkiisu beddelaa sababtoo ah waxay u adkaysan la'dahay heerkulka sare.

Midabka ama midabaynta loo isticmaalo midabaynta balaastikada waxay leeyihiin xad heerkul ah. Marka heerkulka xadka la gaaro, midabada ama midabada ayaa mari doona isbeddel kiimikaad si ay u soo saaraan isku-dhisyada miisaanka unugyada hoose ee kala duwan, iyo hababka falcelintoodu waa kuwo aad u adag; midabyo kala duwan ayaa leh falcelino kala duwan. Iyo alaabooyinka, iska caabinta heerkulka midabada kala duwan waxaa lagu tijaabin karaa hababka falanqaynta sida miisaanka oo yaraada.

2. Midabeeyayaasha waxay kaga falceliyaan alaabada ceeriin

Dareen-celinta u dhaxaysa midabada iyo alaabta ceeriin waxay inta badan ka muuqataa habaynta midabada ama midabaynta iyo alaabta ceeriin. Dareen-celintan kiimikaad waxay u horseedi doontaa isbeddel ku yimaada midabka iyo hoos u dhaca polymers-ka, taas oo beddeleysa sifooyinka alaabta caagga ah.

• Falcelinta Dhimista

Qaar ka mid ah polymers-yada sare, sida naylon iyo aminoplasts, ayaa ah maaddooyin yareeya aashitada oo xooggan ee gobolka dhalaalka ah, kuwaas oo yareyn kara oo lumin kara midabada ama midabada ku xasilan heerkulka habaynta.

• Sarrifka Alkaline

Biraha dhulka alkaline ee ku jira polymers-ka emulsion-ka ee PVC ama polypropylenes-ka xasiloon qaarkood waxay "isweydaarsan karaan" biraha dhulka alkaline ee midabada leh si ay u beddelaan midabka buluug-cas una beddelaan orange.

polymer emulsion PVC waa hab ay VC polymerized by walaaqaya emulsifier ah (sida sodium dodecylsulfonate C12H25SO3Na) xal aqueous. Falcelinta waxay ka kooban tahay Na+; si loo hagaajiyo kulaylka iyo caabbinta oksijiinta ee PP, 1010, DLTDP, iwm ayaa inta badan lagu daraa. Ogsajiinta, antioxidant 1010 waa falcelin transesterification ah oo ay kacday 3,5-di-tert-butyl-4-hydroxypropionate methyl ester iyo sodium pentaerythritol, iyo DLTDP waxaa loo diyaariyey by falcelinta Na2S xal aqueous leh acrylonitrile Propionitrile ugu dambeyntii waa hydrolyzed si ay u abuuraan thiodipropionitrile. lagu helo by esterification leh khamriga lauryl. Falcelinta ayaa sidoo kale ka kooban Na+.

Inta lagu jiro qaabaynta iyo habaynta badeecooyinka balaastikada ah, Na+ hadhaaga ah ee alaabta ceeriin waxay ka falcelinaysaa midabka harada oo ay ku jiraan ion bir ah sida CIPigment Red48: 2 (BBC ama 2BP): XCa2++2Na+→XNa2++Ca2+

• Falcelinta u dhaxaysa Pigments iyo Hydrogen Halides (HX)

Marka heerkulku kor u kaco ilaa 170 ° C ama hoos ficilka iftiinka, PVC waxay ka saartaa HCI si ay u sameeyaan dammaanad laba jibaaran.

Halogen ka kooban polyolefin ololka-celisa ama alaabada caagga ah ee ololka leh ee midabka leh ayaa sidoo kale fuuqbaxa HX marka lagu qaabeeyey heerkul sare.

1) falcelinta Ultramarine iyo HX

Midabka buluuga ah ee Ultramarine oo si weyn loogu isticmaalo midabaynta caaga ah ama baabi'inta iftiinka jaalaha ah, waa iskudhis baaruud ah.

2) Midabka budada dahabka ah ee naxaasta ah wuxuu dardargeliyaa kala-goynta oksaydhka ee alaabta ceeriin ee PVC

Midabka naxaasta ah waxa lagu ogaysiinayaa Cu+ iyo Cu2+ heerkulka sare, kaas oo soo dedejin doona kala-goynta PVC

3) Burburinta ion birta ee polymers-ka

Qaar ka mid ah midabada ayaa saameyn xun ku leh polymers. Tusaale ahaan, midabka harada manganese CIPigmentRed48: 4 kuma habboona samaynta alaabta caagga ah ee PP. Sababta ayaa ah in qiimaha isbedbedelka ah ee birta manganese ions ay kiciso hydroperoxide iyada oo loo marayo wareejinta elektarooniga ee oksaydhka kulaylka ama photooxidation ee PP. Burburinta PP waxay keentaa gabowga degdega ah ee PP; Ester bond ee polycarbonate waa sahlan tahay in la nadiifiyo oo la gooyo marka la kululeeyo, iyo mar haddii ay jiraan ions birta ah ee midabka, way fududahay in kor loo qaado burburka; ions birta ah waxay sidoo kale kor u qaadi doontaa burburka heerkulka-oxygen ee PVC iyo alaabta kale ee cayriin, waxayna keeni doontaa isbeddel midab.

Marka la soo koobo, marka la soo saarayo badeecooyin caag ah, waa habka ugu macquulsan uguna waxtarka badan ee looga fogaado isticmaalka midabada midabka leh ee ka falceliya alaabta ceeriin.

3. Falcelinta u dhaxaysa midabada iyo waxyaabaha lagu daro

1) Falcelinta ka dhaxaysa midabada baaruudku ka kooban yahay iyo waxyaabaha lagu daro

Midabka ka kooban sulfur, sida cadmium jaalaha ah (xalka adag ee CdS iyo CdSe), kuma habboona PVC sababtoo ah caabbinta aysiidhka oo liidata, waana in aan lagu isticmaalin waxyaabo lagu daro sunta rasaasta.

2) Falcelinta xayndaabyada macdanta rasaasta ku jira oo leh xasiliyayaal baaruud ku jira

Maaddooyinka sunta rasaasta ah ee ku jira midabka jaalaha ah ee chrome ama molybdenum cas waxay la falgashaa antioxidants sida thiodistearate DSTDP.

3) Falcelinta u dhaxaysa midabka iyo antioxidant

Qalabka cayriin ee leh antioxidants, sida PP, midabada qaarkood ayaa sidoo kale ka falcelin doona antioxidants, sidaas darteed daciifinta shaqada antioxidants waxayna ka dhigaysaa xasilloonida kuleylka kuleylka ee alaabta ceeriin. Tusaale ahaan, antioxidants phenolic waxaa si fudud u nuugaya kaarboon madow ama la falgala iyaga si ay u lumiyaan dhaqdhaqaaqooda; Antioxidants phenolic iyo ion titanium ee alaabada caaga ah ee cad ama midabka iftiinka leh waxay sameeyaan dhismayaal hydrocarbon udgoon oo udgoon si ay u keenaan jaale alaabada. Dooro antioxidant ku habboon ama ku dar waxyaabo dheeri ah, sida anti-acid zinc milix (zinc stearate) ama P2 nooca fosfit si looga hortago midab-beelka midabka cad (TiO2).

4) Falcelinta u dhaxaysa midabka iyo xasiliyeyaasha iftiinka

Saamaynta midabada iyo xasiliyeyaasha iftiinka, marka laga reebo falcelinta midabada sulfur-ku jira iyo xasiliyeyaasha iftiinka nikkel-ku jira sida kor lagu sharaxay, guud ahaan waxay yareysaa waxtarka xasilinta iftiinka, gaar ahaan saameynta xannibaadaha amine light stabilizers iyo azo pigments huruud iyo casaan. Saamaynta hoos u dhaca xasillooni waa mid aad u muuqda, mana aha mid deggan sida midab la'aanta. Ma jirto sharraxaad qeexan oo ku saabsan dhacdadan.

4. Falcelinta ka dhaxaysa waxyaabaha lagu daro

Haddii waxyaabo badan oo lagu daro si khaldan loo isticmaalo, falcelin lama filaan ah ayaa laga yaabaa inay dhacaan badeecaduna waxay bedeli doontaa midab. Tusaale ahaan, ololka celiyaha Sb2O3 wuxuu la falgalaa sulfur-ka kooban anti-oxidant si uu u dhaliyo Sb2S3: Sb2O3+–S–→Sb2S3+–O–

Sidaa darteed, waa in laga taxadaraa xulashada waxyaabaha lagu daro marka la tixgelinayo qaababka wax soo saarka.

5. Sababaha Kaaliyaha Auto-oxidation

Oksijiinta tooska ah ee xasiliyeyaasha phenolic waa arrin muhiim ah si kor loogu qaado midabaynta alaabta cad ama midabka iftiinka. Midab-soo-baxan waxaa badanaa loogu yeeraa "Pinking" wadamada shisheeye.

Waxaa lagu daraa alaabada oksaydhka ah sida antioxidants BHT (2-6-di-tert-butyl-4-methylphenol), waxayna u qaabaysan tahay 3,3′,5,5′-stilbene quinone sheyga falcelinta cas ee iftiinka, Midabayntani waxay dhacdaa. kaliya marka ay joogaan ogsijiinta iyo biyaha iyo maqnaanshaha iftiinka. Marka uu soo gaadho iftiinka ultraviolet, iftiinka cas ee stilbene quinone wuxuu si degdeg ah u jajabiyaa alaab jaale ah oo hal giraan ah.

6. Tautomerization of Pigments Midabo Hoosta Ficilka Iftiinka iyo Kulaylka

Qaar ka mid ah midabada midabka leh waxay maraan tautomerization qaabeynta molecular ee hoos yimaada ficilka iftiinka iyo kulaylka, sida isticmaalka midabka CIPig.R2 (BBC) si ay uga beddelaan nooca azo ilaa nooca quinone, taas oo beddeleysa saameynta isku-xidhka asalka ah waxayna sababtaa samaynta curaarta isku xiran. . hoos u dhac, taasoo keentay in midab beddelo ka casaan buluug-buluug ah oo dhalaalaya oo iftiin ah orange-cas.

Isla mar ahaantaana, hoosta iftiinka iftiinka, waxay ku jajabisaa biyaha, beddelaadda biyaha co-crystal waxayna keenaysaa dhumuc.

7. Waxaa keena Wasakhowga Hawada

Marka alaabta caaga ah la kaydiyo ama la isticmaalo, walxaha falcelinta qaarkood, ha ahaadeen alaabta ceeriin, wax lagu daro, ama midabaynta, waxay ka falcelinayaan qoyaanka jawiga ama wasakhowga kiimikaad sida asiidh iyo alkalis oo hoos yimaada iftiinka iyo kulaylka. Falcelin kiimikaad oo kala duwan ayaa keena, kuwaas oo keeni doona in ay libdhaan ama midab beddelaan muddo ka dib.

Xaaladdan waa laga fogaan karaa ama waa la yareyn karaa iyadoo lagu darayo xasiliyeyaasha oksijiinta kulaylka ku habboon, xasiliyeyaasha iftiinka, ama xulashada waxyaabo lagu daro cimilada oo tayo sare leh iyo midabyo.