Wasu Muhimman dalilai don lalata rufin polyester

Rashin lalata polyester yana shafar hasken rana, abubuwan da ake amfani da su na photocatalytic, ruwa da danshi, sunadarai, oxygen, ozone, zafin jiki, abrasion, damuwa na ciki da na waje, da launin launi. Mafi mahimmanci don lalata lalata:

danshi, yanayin zafi, iskar shaka, UV radiation.

danshi

Hydrolysis yana faruwa a lokacin da filastik ke nunawa ga ruwa ko zafi. Wannan sinadarai na iya zama babban mahimmanci a cikin lalata polymers na condensation irin su polyesters , inda ƙungiyar ester ta zama hydrolyzed.

Zafin jiki

Lokacin da polymer ya kasance ƙarƙashin makamashi mai zafi wanda ya fi ƙarfin haɗin gwiwa wanda ke riƙe da atom ɗin tare, an raba shi da sauri. A sakamakon haka, ana haifar da macroradicals guda biyu, ko ƙananan ƙwayoyin lantarki.
Yawancin robobi sune kwayoyin halittarally kimantawa a cikin yanayi guda uku na haɓaka-zazzabi mai ɗaukar hoto: yanayin zafi mai tsayi na dogon lokaci, yanayin zafi mai tsayi a cikin ɗan gajeren lokaci, ko yanayin hawan keke zuwa yanayin zafi mai girma da saukarwa, kamar na iya faruwa yayin musayar rana da dare. ana ƙara yawan zafin jiki, ana ƙara haɓaka tasirin lalacewa ta hanyar ƙarin bayyanar UV.

Hawan iska

Saboda kasancewar iskar oxygen a cikin yanayi, mafi yawan nau'in lalacewa na radiation, photooxidation, yana faruwa a kan dukkanin kwayoyin halitta. Bugu da ƙari, za a ƙara haɓaka aikin ta UV radiation da mafi girman yanayin zafi. Ana iya kwatanta halayen sinadaran ta hanyar harin oxygen akan haɗin gwiwa a cikin sarkar polymer, wanda zai iya samar da ƙungiyoyin carbonyl ko crosslink.Za a iya amfani da ma'auni daban-daban don rage lalata polymer: antioxidants, thermostabilizers, photostabilizers, da dai sauransu.

Radiation UV

Lokacin da yazo ga aikace-aikacen waje, babban abin damuwa a cikin ƙimar kayan abu shine yuwuwar lalacewar hasken rana lokacin da ake nufi da robobi don amfani da waje. Daga cikin jimillar radiation da ta kai saman duniya, kusan 5-6% na hasken yana cikin yankin UV. na bakan kuma yawanci zai bambanta da yanayin yanayi na yau da kullun.
Tasirin photochemical na hasken rana akan kayan filastik ya dogara da abubuwan sha na zahiri da kuzarin haɗin sinadarai na kayan. Tsawon raƙuman haske waɗanda suka fi tasiri akan robobi suna daga 290 zuwa 400 nm. Tsayin hasken UV wanda makamashin photon ya yi daidai da wani makamashi na musamman a cikin sarkar polymer zai iya karya haɗin sinadarai (ta hanyar sarkar sarkar), canza kaddarorin, sabili da haka aikin polymer.6 Mafi lalata raƙuman ruwa ga polyesters shine. an yi imani da 325 nm