Chiyambi cha choyatsira UV

Kuwala kwa dzuwa kuli ndi kuwala kwa ultraviolet kochuluka komwe kumawononga zinthu zamitundu yosiyanasiyana. Kutalika kwake kwa mafunde ndi pafupifupi 290 ~ 460nm. Kuwala kwa ultraviolet koopsa kumeneku kumapangitsa kuti mamolekyu amitundu awole ndi kuzimiririka kudzera mu zochita zochepetsa okosijeni. Kugwiritsa ntchito ma ultraviolet absorbers kumatha kupewa kapena kufooketsa kuwonongeka kwa kuwala kwa ultraviolet ku zinthu zotetezedwa.

Choyatsira UV ndi choyatsira kuwala chomwe chingathe kuyamwa mbali ya ultraviolet ya kuwala kwa dzuwa ndi magwero a kuwala kwa fluorescent popanda kusintha chokha. Mapulasitiki ndi zinthu zina za polima zimapanga ma auto-oxidation reactions pansi pa kuwala kwa dzuwa ndi kuwala kwa fluorescence chifukwa cha mphamvu ya kuwala kwa ultraviolet, zomwe zimapangitsa kuti ma polima aziwonongeka, komanso kuwonongeka kwa mawonekedwe ndi mawonekedwe a makina. Pambuyo powonjezera ma UV absorbers, kuwala kwa ultraviolet kwamphamvu kumeneku kumatha kuyamwa mosankha, ndikusandutsa mphamvu yopanda vuto ndikutulutsidwa kapena kugwiritsidwa ntchito. Chifukwa cha mitundu yosiyanasiyana ya ma polima, kutalika kwa kutalika kwa kuwala kwa ultraviolet komwe kumawapangitsa kuwonongeka nakonso kumasiyana. Ma UV absorbers osiyanasiyana amatha kuyamwa kuwala kwa ultraviolet kwa mafunde osiyanasiyana. Pogwiritsa ntchito, ma UV absorbers ayenera kusankhidwa malinga ndi mtundu wa polima.

Mitundu ya ma absorber a UV

Mitundu yodziwika bwino ya zoyamwitsa za UV ndi iyi: benzotriazole (mongaChoyatsira UV 327), benzophenone (mongaChoyatsira UV 531), triazine (mongaChoyatsira UV 1164), ndi amine yolepheretsa (mongaChokhazikitsa Mphamvu 622).

Ma Benzotriazole UV absorbers ndi omwe amagwiritsidwa ntchito kwambiri ku China pakadali pano, koma zotsatira za ma triazine UV absorbers ndi zabwino kwambiri kuposa za benzotriazole. Ma Triazine absorbers ali ndi mphamvu zabwino kwambiri zoyamwa UV komanso zabwino zina. Angagwiritsidwe ntchito kwambiri mu ma polima, ali ndi kukhazikika kwa kutentha, kukhazikika bwino pakukonza, komanso kukana asidi. Mu ntchito zenizeni, ma triazine UV absorbers ali ndi mphamvu yabwino yogwirizana ndi ma amine light stabilizers oletsedwa. Zikagwiritsidwa ntchito limodzi, zimakhala ndi zotsatira zabwino kuposa zikagwiritsidwa ntchito zokha.

Ma absorber a UV ambiri omwe amapezeka nthawi zambiri

(1)UV-531
Ufa wa kristalo wopepuka wachikasu kapena woyera. Kuchulukana 1.160g/cm³ (25℃). Malo osungunuka 48~49℃. Sungunuka mu acetone, benzene, ethanol, isopropanol, imasungunuka pang'ono mu dichloroethane, yosasungunuka m'madzi. Kusungunuka mu zosungunulira zina (g/100g, 25℃) ndi acetone 74, benzene 72, methanol 2, ethanol (95%) 2.6, n-heptane 40, n-hexane 40.1, madzi 0.5. Monga choyamwa UV, imatha kuyamwa kuwala kwa ultraviolet mwamphamvu ndi kutalika kwa 270~330nm. Itha kugwiritsidwa ntchito mu mapulasitiki osiyanasiyana, makamaka polyethylene, polypropylene, polystyrene, ABS resin, polycarbonate, polyvinyl chloride. Imagwirizana bwino ndi ma resin komanso kusasinthasintha kochepa. Mlingo wamba ndi 0.1%~1%. Ili ndi mphamvu yabwino yogwirizana ikagwiritsidwa ntchito ndi 4,4-thiobis (6-tert-butyl-p-cresol) pang'ono. Chogulitsachi chingagwiritsidwenso ntchito ngati chowongolera kuwala pamitundu yosiyanasiyana ya zokutira.

(2)UV-327
Monga choyamwa UV, makhalidwe ake ndi ntchito zake zimafanana ndi za benzotriazole UV-326. Imatha kuyamwa kwambiri kuwala kwa ultraviolet ndi kutalika kwa 270 ~ 380nm, imakhala ndi kukhazikika kwa mankhwala abwino komanso kusasinthasintha kochepa kwambiri. Imagwirizana bwino ndi polyolefins. Ndi yoyenera kwambiri polyethylene ndi polypropylene. Kuphatikiza apo, ingagwiritsidwenso ntchito pa polyvinyl chloride, polymethyl methacrylate, polyoxymethylene, polyurethane, unsaturated polyester, ABS resin, epoxy resin, cellulose resin, ndi zina zotero. Chogulitsachi chimalimbana bwino ndi kutentha, kukana kusamba, kukana kutha kwa mpweya komanso kusunga mphamvu ya makina. Chimakhala ndi mphamvu yogwirizana kwambiri chikagwiritsidwa ntchito limodzi ndi ma antioxidants. Chimagwiritsidwa ntchito kukonza kukhazikika kwa kutentha kwa chinthucho.

(3)UV-9
Ufa wa kristalo wachikasu kapena woyera. Kuchulukana 1.324g/cm³. Malo osungunuka 62~66℃. Malo otentha 150~160℃ (0.67kPa), 220℃ (2.4kPa). Sungunuka mu zinthu zambiri zachilengedwe monga acetone, ketone, benzene, methanol, ethyl acetate, methyl ethyl ketone, ethanol, koma osasungunuka m'madzi. Kusungunuka mu zinthu zina zosungunulira (g/100g, 25℃) ndi solvent benzene 56.2, n-hexane 4.3, ethanol (95%) 5.8, carbon tetrachloride 34.5, styrene 51.2, DOP 18.7. Monga choyamwa UV, ndi choyenera mapulasitiki osiyanasiyana monga polyvinyl chloride, polyvinylidene chloride, polymethyl methacrylate, unsaturated polyester, ABS resin, cellulose resin, ndi zina zotero. Kutalika kwa mafunde oyamwa ndi 280 ~ 340nm, ndipo mlingo wonse ndi 0.1% ~ 1.5%. Chili ndi kutentha kolimba ndipo sichimawola pa 200℃. Chogulitsachi sichimayamwa kuwala kooneka, kotero ndi choyenera zinthu zowala zowonekera. Chogulitsachi chingagwiritsidwenso ntchito mu utoto ndi rabara yopangidwa.