Zipangizo zophimba za polyurethane zimatha kuoneka zachikasu pakapita nthawi chifukwa cha kuwala kwa ultraviolet kapena kutentha, zomwe zimakhudza mawonekedwe awo ndi moyo wawo. Mwa kuyambitsa UV-320 ndi 2-hydroxyethyl thiophosphate mu unyolo wa polyurethane, polyurethane yopanda ionic yokhala ndi madzi yokhala ndi kukana kwabwino kwa chikasu idakonzedwa ndikugwiritsidwa ntchito pa utoto wa chikopa. Kudzera mu kusiyana kwa mitundu, kukhazikika, microscope ya scanning electron, X-ray spectrum ndi mayeso ena, zidapezeka kuti kusiyana konse kwa mitundu △E ya chikopa chomwe chidathandizidwa ndi magawo 50 a polyurethane yopanda ionic yokhala ndi madzi yokhala ndi kukana kwabwino kwa chikasu chinali 2.9, kalasi yosintha mtundu inali kalasi 1, ndipo panali kusintha pang'ono kwa mtundu. Kuphatikiza ndi zizindikiro zoyambira za mphamvu yokoka ya chikopa ndi kukana kuvala, zikuwonetsa kuti polyurethane yokonzedwa yokana chikasu imatha kukonza kukana kwa chikasu kwa chikopa pamene ikusunga mawonekedwe ake amakina komanso kukana kuvala.

Pamene miyoyo ya anthu yasintha, anthu ali ndi zofunikira zapamwamba pa mipando yachikopa, osati kungofuna kuti ikhale yopanda vuto pa thanzi la anthu, komanso kuti ikhale yokongola. Polyurethane yochokera m'madzi imagwiritsidwa ntchito kwambiri popanga zokutira zachikopa chifukwa cha chitetezo chake chabwino komanso magwiridwe antchito ake osadetsa kuipitsa, kuwala kwambiri, komanso kapangidwe kake ka amino methylidynephosphonate kofanana ndi ka chikopa. Komabe, polyurethane yochokera m'madzi imatha kuoneka yachikasu ikakhudzidwa ndi kuwala kwa ultraviolet kapena kutentha kwa nthawi yayitali, zomwe zimakhudza moyo wa ntchito ya nsaluyo. Mwachitsanzo, zinthu zambiri zoyera za polyurethane nthawi zambiri zimawoneka zachikasu, kapena pamlingo waukulu kapena pang'ono, padzakhala chikasu pansi pa kuwala kwa dzuwa. Chifukwa chake, ndikofunikira kuphunzira momwe polyurethane yochokera m'madzi imakanira chikasu.

Pakadali pano pali njira zitatu zowonjezera kukana kwachikasu kwa polyurethane: kusintha kuchuluka kwa magawo olimba ndi ofewa ndikusintha zinthu zopangira kuchokera ku zomwe zimayambitsa, kuwonjezera zowonjezera zachilengedwe ndi zinthu zina, komanso kusintha kapangidwe kake.

(a) Kusintha kuchuluka kwa magawo olimba ndi ofewa ndikusintha zipangizo zopangira kungathetse vuto la polyurethane yokha kukhala yachikasu, koma sikungathetse mphamvu ya chilengedwe chakunja pa polyurethane ndipo sikungakwaniritse zofunikira pamsika. Kudzera mu TG, DSC, kukana kukwawa ndi kuyesa kwa kupsinjika, zidapezeka kuti mawonekedwe enieni a polyurethane yokonzedwa yolimbana ndi nyengo ndi chikopa chotsukidwa ndi polyurethane yoyera anali ofanana, zomwe zikusonyeza kuti polyurethane yolimbana ndi nyengo imatha kusunga mawonekedwe oyambira a chikopa pomwe ikukweza kwambiri kukana kwake nyengo.

(b) Kuwonjezera zinthu zina zachilengedwe ndi zinthu zina zomwe zili ndi zinthu zina kumabweretsa mavuto monga kuchuluka kwa zinthu zomwe zawonjezeredwa komanso kusasakaniza bwino zinthu ndi polyurethane, zomwe zimapangitsa kuti zinthu za polyurethane zisamagwire bwino ntchito.

(c) Ma bond a Disulfide ali ndi mphamvu yosinthika yamphamvu, zomwe zimapangitsa kuti mphamvu zawo zoyatsira zikhale zochepa kwambiri, ndipo amatha kusweka ndikumangidwanso kangapo. Chifukwa cha mphamvu yosinthika ya ma bond a disulfide, ma bond awa amasweka nthawi zonse ndikumangidwanso pansi pa kuwala kwa ultraviolet, zomwe zimapangitsa mphamvu ya kuwala kwa ultraviolet kukhala mphamvu yotulutsa kutentha. Kufiira kwa polyurethane kumachitika chifukwa cha kuwala kwa ultraviolet, komwe kumasangalatsa ma bond a mankhwala mu zinthu za polyurethane ndikuyambitsa kugawanika kwa ma bond ndi kukonzanso, zomwe zimapangitsa kusintha kwa kapangidwe kake ndi chikasu cha polyurethane. Chifukwa chake, poyika ma bond a disulfide m'magawo a unyolo wa polyurethane wozikidwa pamadzi, magwiridwe antchito a polyurethane odzichiritsa okha komanso okana chikasu adayesedwa. Malinga ndi mayeso a GB/T 1766-2008, △E inali 4.68, ndipo kalasi yosintha mtundu inali mulingo wachiwiri, koma popeza idagwiritsa ntchito tetraphenylene disulfide, yomwe ili ndi mtundu winawake, siyoyenera polyurethane yokana chikasu.

Zoyamwa kuwala kwa ultraviolet ndi disulfides zimatha kusintha kuwala kwa ultraviolet komwe kumayamwa kukhala mphamvu yotentha kuti zichepetse mphamvu ya kuwala kwa ultraviolet pa kapangidwe ka polyurethane. Mwa kuyambitsa chinthu chosinthika cha 2-hydroxyethyl disulfide mu gawo lokulitsa kapangidwe ka polyurethane, chimalowetsedwa mu kapangidwe ka polyurethane, komwe ndi disulfide compound yokhala ndi magulu a hydroxyl omwe ndi osavuta kuchita ndi isocyanate. Kuphatikiza apo, UV-320 ultraviolet absorber imayambitsidwa kuti igwirizane ndi kusintha kwa kukana kwachikasu kwa polyurethane. UV-320 yokhala ndi magulu a hydroxyl, chifukwa cha khalidwe lake lochita zinthu mosavuta ndi magulu a isocyanate, imathanso kulowetsedwa mu magawo a polyurethane chain ndikugwiritsidwa ntchito pakati pa chikopa kuti ikonze kukana kwachikasu kwa polyurethane.

Kudzera mu mayeso a kusiyana kwa mitundu, zidapezeka kuti kukana kwachikasu kwa polyureth yokana yachikasu. Kudzera mu TG, DSC, kukana kukwawa ndi kuyesa kwa kupsinjika, zidapezeka kuti mawonekedwe enieni a polyurethane yokonzedwa yokana nyengo ndi chikopa chokonzedwa ndi polyurethane yoyera zinali zofanana, zomwe zikusonyeza kuti polyurethane yokana nyengo imatha kusunga mawonekedwe oyambira a chikopa pomwe ikukweza kwambiri kukana kwake nyengo.