Kuyambitsa thovu lothandizira thovu lolimba la polyurethane lomwe limagwiritsidwa ntchito pomanga
Chifukwa cha kuwonjezeka kwa kufunika kwa nyumba zamakono zosungira mphamvu ndi kuteteza chilengedwe, magwiridwe antchito a zida zomangira zotetezera kutentha akukhala ofunikira kwambiri. Pakati pawo, thovu lolimba la polyurethane ndi chinthu chabwino kwambiri chotetezera kutentha, chokhala ndi mphamvu zabwino zamakanika, kutentha kochepa komanso zabwino zina, kotero chimagwiritsidwa ntchito kwambiri pantchito yoteteza kutentha kwa nyumba.
Chopangira thovu ndi chimodzi mwa zinthu zofunika kwambiri popanga thovu lolimba la polyurethane. Malinga ndi momwe limagwirira ntchito, lingagawidwe m'magulu awiri: chopangira thovu cha mankhwala ndi chopangira thovu chakuthupi.
Kugawa kwa mankhwala a thovu
Chothandizira thovu cha mankhwala ndi chowonjezera chomwe chimapanga zinthu za polyurethane zopangidwa ndi mpweya ndi thovu panthawi ya zochita za isocyanates ndi polyols. Madzi ndi omwe amayimira chothandizira thovu cha mankhwala, chomwe chimagwirizana ndi gawo la isocyanate kuti chipange mpweya wa carbon dioxide, kuti chipange thovu ku polyurethane. Chothandizira thovu cha thupi ndi chowonjezera chomwe chimawonjezeredwa popanga thovu lolimba la polyurethane, lomwe limapanga thovu ku zinthu za polyurethane kudzera mu mphamvu ya mpweya. Zothandizira thovu la thupi makamaka ndi zinthu zachilengedwe zotentha pang'ono, monga hydrofluorocarbons (HFC) kapena alkane (HC).
Njira yopangira chitukuko chachothandizira thovuKampani ya DuPont inayamba kumapeto kwa zaka za m'ma 1950, ndipo inagwiritsa ntchito trichloro-fluoromethane (CFC-11) ngati chopangira thovu la polyurethane hard thovu, ndipo inapeza ntchito yabwino kwambiri, kuyambira pamenepo CFC-11 yakhala ikugwiritsidwa ntchito kwambiri pa thovu la polyurethane hard thovu. Pamene CFC-11 inatsimikizira kuwononga ozoni, mayiko akumadzulo kwa Europe anasiya kugwiritsa ntchito CFC-11 pofika kumapeto kwa chaka cha 1994, ndipo China inaletsanso kupanga ndi kugwiritsa ntchito CFC-11 mu 2007. Pambuyo pake, United States ndi Europe zinaletsa kugwiritsa ntchito CFC-11 m'malo mwa HCFC-141b mu 2003 ndi 2004, motsatana. Pamene chidziwitso cha zachilengedwe chikuwonjezeka, mayiko akuyamba kupanga ndikugwiritsa ntchito njira zina zomwe zili ndi mphamvu yochepa yotenthetsera dziko (GWP).
Zopangira thovu zamtundu wa Hfc kale zinali zolowa m'malo mwa CFC-11 ndi HCFC-141b, koma mtengo wa GWP wa zosakaniza zamtundu wa HFC ukadali wokwera, zomwe sizithandiza kuteteza chilengedwe. Chifukwa chake, m'zaka zaposachedwa, cholinga chachikulu cha zopanga thovu m'gawo lomanga chasanduka njira zina zogwiritsira ntchito GWP yochepa.
Ubwino ndi kuipa kwa zinthu zodzola thovu
Monga mtundu wa zinthu zotetezera kutentha, thovu lolimba la polyurethane lili ndi zabwino zambiri, monga magwiridwe antchito abwino kwambiri otetezera kutentha, mphamvu yabwino yamakina, magwiridwe antchito abwino oyamwa phokoso, moyo wautali wokhazikika ndi zina zotero.
Monga chothandizira chofunikira pakukonzekera thovu lolimba la polyurethane, chopangira thovu chimakhudza kwambiri magwiridwe antchito, mtengo ndi chitetezo cha chilengedwe cha zinthu zotetezera kutentha. Ubwino wa chopangira thovu cha mankhwala ndi kuthamanga kwa thovu mwachangu, thovu lofanana, lingagwiritsidwe ntchito kutentha ndi chinyezi chosiyanasiyana, limatha kupeza mphamvu zambiri zotulutsa thovu, kuti likonzekere thovu lolimba la polyurethane logwira ntchito bwino.
Komabe, mankhwala opangira thovu amatha kupanga mpweya woipa, monga carbon dioxide, carbon monoxide ndi nitrogen oxides, zomwe zimayambitsa kuipitsa chilengedwe. Ubwino wa mankhwala opangira thovu ndi wakuti sapanga mpweya woipa, sakhudza kwambiri chilengedwe, komanso amatha kuchepetsa kukula kwa thovu komanso kutenthetsa bwino. Komabe, mankhwala opangira thovu amakhala ndi mphamvu yochepa yotulutsa thovu ndipo amafunika kutentha ndi chinyezi chambiri kuti agwire bwino ntchito.
Monga mtundu wa zinthu zotetezera kutentha, thovu lolimba la polyurethane lili ndi zabwino zambiri, monga magwiridwe antchito abwino kwambiri otetezera kutentha, mphamvu yabwino yamakina, magwiridwe antchito abwino oyamwa phokoso, moyo wautali wokhazikika ndi zina zotero.
Monga chothandizira chofunikira pakukonzekerathovu lolimba la polyurethaneChopangira thovu chimakhudza kwambiri magwiridwe antchito, mtengo, komanso chitetezo cha chilengedwe cha zinthu zotetezera kutentha. Ubwino wa chopangira thovu cha mankhwala ndi kuthamanga kwa thovu mwachangu, thovu lofanana, lingagwiritsidwe ntchito kutentha ndi chinyezi chosiyanasiyana, limatha kupeza thovu lochuluka, kuti likonzekere thovu lolimba la polyurethane logwira ntchito bwino.
Komabe, mankhwala opangira thovu amatha kupanga mpweya woipa, monga carbon dioxide, carbon monoxide ndi nitrogen oxides, zomwe zimayambitsa kuipitsa chilengedwe. Ubwino wa mankhwala opangira thovu ndi wakuti sapanga mpweya woipa, sakhudza kwambiri chilengedwe, komanso amatha kuchepetsa kukula kwa thovu komanso kutenthetsa bwino. Komabe, mankhwala opangira thovu amakhala ndi mphamvu yochepa yotulutsa thovu ndipo amafunika kutentha ndi chinyezi chambiri kuti agwire bwino ntchito.
Zochitika zamtsogolo pa chitukuko
Chizolowezi cha zinthu zopangira thovu m'makampani omanga mtsogolo chimayang'ana kwambiri pakupanga zinthu zosinthira za GWP zochepa. Mwachitsanzo, CO2, HFO, ndi njira zina zamadzi, zomwe zili ndi GWP yochepa, ODP yocheperako, ndi magwiridwe ena oteteza chilengedwe, zakhala zikugwiritsidwa ntchito kwambiri popanga thovu lolimba la polyurethane. Kuphatikiza apo, pamene ukadaulo wazinthu zotetezera nyumba ukupitilira kukula, chinthu chopangira thovu chidzapanganso magwiridwe antchito abwino kwambiri, monga kutetezera bwino, kuchuluka kwa thovu, komanso kukula kochepa kwa thovu.
M'zaka zaposachedwapa, makampani opanga mankhwala a organofluorine m'dziko ndi kunja akhala akufufuza mwakhama ndikupanga zinthu zatsopano zotulutsa thovu zomwe zili ndi fluorine, kuphatikizapo zinthu zotulutsa thovu za fluorinated olefins (HFO), zomwe zimatchedwa zinthu zotulutsa thovu za m'badwo wachinayi ndipo ndi zinthu zotulutsa thovu zomwe zimakhala ndi mpweya wabwino komanso zabwino pa chilengedwe.
Nthawi yotumizira: Juni-21-2024