soo-gaadhista shucaaca ultraviolet
Soo-gaadhista shucaaca ultraviolet ee qorraxda waxay hoos u dhigi kartaa balaastiga muddo ka dib. Burburinta sawir-qaadista polymer waxay dhacdaa marka shucaaca ultraviolet ee aan la arki karin ee ka kooban mowjadaha dhererka gaaban uu jebiyo silsiladaha polymer ee balaastikada. Tan waxa loo yaqaan habka sawir-qaadista. Waxaa sababa soo-gaadhista shucaaca ultraviolet oo sababa hoos u dhaca hantida jidheed. Kuwaas waxaa ka mid ah luminta xoogga saameynta, isbeddelka midabka, dildilaaca, luminta dhererka iyo xoogga jilicsanaanta, iyo caleenta dusha sare. Tusaale ahaan, sawir-xumada uu keeno shucaaca UV waxay keeni kartaa in kuraasta beerta ay xumeeyaan oo ay noqdaan kuwo jajaban. Intaa waxaa dheer, midabka kuraasta garoonka ayaa u muuqan doona mid jilicsan, iyo caagadaha qaarkood xitaa jaalaha iyo dildilaaca.
Qaar ka mid ah Astaamaha Shucaaca Ultraviolet
Shucaaca ultraviolet wuxuu ka kooban yahay kaliya 4.6 boqolkiiba spectrum qorraxda. Waxaa lagu qiyaasaa nanometers (nm) waxayna u dhaxaysaa 290 ilaa 400. Si kastaba ha ahaatee, qaybta ugu gardarrada badan ee UVB waa mawjadaha aadka u gaaban ee u dhexeeya 280 iyo 315 nanometers. Sidaa darteed, cadadka soo-gaadhista tamarta shucaaca UV (radiation) waxay kuxirantahay meesha aad ka joogto aduunka.
waa maxay shucaac
Irradiance waa qadarka shilka tamarta shucaaca ultraviolet ee meel gaar ah muddo cayiman{0}}Ly {{1} cal/cm 2=4.184 E 4 Joule/m 2
Caag kastaa waxay u nugul yihiin hirarka hirarka qaarkood ee gobolka 290-400 nm UV. Sidaa darteed, polypropylene waxay leedahay saddex maxima oo ah 290-300, 330 iyo 370 nm. Naylon waxay u dhaxaysaa 290-315, halka PVC homopolymer ay tahay 320.
Hoos-u-dhac ku yimaada Polymers by Shucaaca UV
Burburinta sawir-qaadista polymer waxay dhacdaa marka shucaaca ultraviolet ee qorraxda ay nuugaan kooxaha kiimikada ee qaab-dhismeedka polymerka ee loo yaqaan 'chromophores'. Koromophore waa "atom ama koox atamka ah oo joogitaankoodu go'aamiyo midabka isku-dhafka". Qaababka polymer-ka waxaa ku jiri kara waxyaabo kale oo lagu daro sida ololka halogenated, buuxinta iyo midabada. Sidaa darteed, xasiliyayaasha UV ayaa la sameeyay waxaana lagu daray polymers si loo xakameeyo habka sawir-qaadista. Saddexda nooc ee ugu horreeya waa kuwa nuugaya UV, quenchers, iyo kuwa xasiliya iftiinka aminiga ah (HALS).
1) Nuugista UV
Absorbers waa sawir-qaadayaal ka shaqeeya iyagoo la tartamaya koromophore-yada si ay u nuugaan shucaaca UV. Sidaa darteed, nuugagu wuxuu u beddelaa shucaaca UV ee waxyeellada leh oo u beddela shucaac infrared ah oo aan waxyeello lahayn ama kulaylka ku faafaya matrixka polymerka. Nuugayaasha UV waxay faa'iido u leeyihiin inay noqdaan qiime jaban, laakiin waxa laga yaabaa inay ku habboon yihiin oo keliya{2} soo-gaadhista muddada gaaban. Nuugayaasha UV waxaa ka mid ah:
Nuugista
Nuugayaasha UV waxay faa'iido u leeyihiin inay noqdaan qiime jaban, laakiin waxa laga yaabaa inay ku habboon yihiin oo keliya{0} soo-gaadhista muddada gaaban. Nuugayaasha UV waxaa ka mid ah:
Kaarboon madow waa mid ka mid ah kuwa ugu waxtarka badan uguna badan ee la isticmaalo nuuga shucaaca UV.
Mid kale oo nuuga UV ah waa rutile titanium oxide, kaas oo wax ku ool u ah 300-400 nm. Si kastaba ha ahaatee, aad faa'iido uguma leh mawjada dhererka UVB ee aadka u gaaban ee ka hooseeya 315.
Hydroxybenzophenone
Hydroxyphenyl benzotriazole sidoo kale waa xasiliye UV caan ah oo faa'iido u leh inuu ku habboon yahay codsiyada dhexdhexaadka ah ama cad. Hydroxyphenylbenzotriazoles faa'iido badan uma laha qaybaha khafiifka ah ee ka hooseeya 100 microns.
Benzophenone ee PVC
Anzotriazoles iyo hydroxyphenyltriazines ee polycarbonates.
Oxalanilide ee polyamides
2) Quencher
Quenchers waxay ku soo celiyaan xaalada xiisaha leh ee koromophore-ka dhulka iyadoo loo marayo habka wareejinta tamarta. Wakiilada wareejinta tamarta waxay u dhaqmaan iyagoo deminayo xaalada xiisaha leh ee kooxaha kaarboonyl ee la sameeyay inta lagu guda jiro photooxidation ee alaabada balaastikada ah iyo kala furfurida hydroperoxides. Tani waxay ka hortagtaa jebinta bonds iyo ugu dambeyntii samaynta xagjirka xorta ah.
Wakiilka deminta nikkel
Nickel quencher waa nooca inta badan loo isticmaalo soo saarista filimada beeraha. Kuwaas si weyn looma isticmaalo sababtoo ah waxay ka kooban yihiin biro culus waxayna siinayaan badeecada ugu dambeysa midab madow ama cagaar ah. Si kastaba ha ahaatee, sida xasiliyayaasha iftiinka aminiga ah ee hoos looga hadlay, nikkel quenchers waxtar uma laha xasilinta shucaaca UV.
3) Amine Light Stabilizer (HALS) oo xannibay
HALS waa dheeraa{0}kuleyl waarta oo ka shaqeeya dabinka xagjirka xorta ah ee la sameeyay inta lagu jiro photooxidation ee alaabta caaga ah. HALS sidaas darteed waxay xaddidaysaa habka sawir-xumada. Awoodda HALS si ay uga takhalusto xagjirnimada xorta ah ee ka dhasha nuugista shucaaca UV waxaa lagu sharxi karaa samaynta kooxaha nitroxyl ee habka loo yaqaan wareegga Denisov.
Inkasta oo alaabta HALS ee ganacsi ahaan loo heli karo ay si weyn ugu kala duwan yihiin qaab dhismeedka, dhammaantood waxay leeyihiin qaab dhismeedka giraanta 2,2,6,6-tetramethylpiperidine. HALS waa qaar ka mid ah kuwa ugu aqoonta badan xasiliya shucaaca UV.
Xasilinta UV ee Caagag kala duwan
Tusaale ahaan, HALS waxay gacan ka gaysatay horumarinta polypropylene ee warshadaha baabuurta. Halka HALS ay sidoo kale aad waxtar ugu leedahay polyolefins, polyetylen iyo polyurethane, looma isticmaali karo xasiliyayaal shucaaca UV ee PVC.
Isku-dhafka UV Stabilizers
Maadaama dhammaan saddexda hawlood ay ku shaqeeyaan habab kala duwan, waxay inta badan isku daraan wax lagu daro shucaaca UV ee isku-dhafka ah. Tusaale ahaan, benzotriazoles ayaa inta badan loo isticmaalaa marka lagu daro HALS si looga hortago libista iyo midabka nidaamka midabaynta.
