Ulwazi malunga nokuguga kwerabha

1. Kuthetha ukuthini ukuguga kwerabha? Oku kubonisa ntoni kumphezulu?
Kwinkqubo yokucubungula, ukugcinwa nokusetyenziswa kwerabha kunye neemveliso zayo, ngenxa yesenzo esibanzi sezinto zangaphakathi nezangaphandle, iimpawu zomzimba nezekhemikhali kunye neempawu zoomatshini zerabha ziyawohloka kancinci kancinci, kwaye ekugqibeleni zilahlekelwa lixabiso lazo lokusetyenziswa. Olu tshintsho lubizwa ngokuba kukwaluphala kwerabha. Ngaphezulu, lubonakala njengeentanda, ukunamathela, ukuqina, ukuthamba, ukutshixa, ukutshintsha kombala, kunye nokukhula kwesikhunta.
2. Ziziphi izinto ezichaphazela ukwaluphala kwerabha?
Izinto ezibangela ukuguga kwerabha zezi:
(a) Ioksijini kunye neoksijini ekwirabha zifumana i-free radical chain reaction kunye neemolekyuli zerabha, kwaye i-molecular chain iyaphuka okanye idityaniswe kakhulu, nto leyo ebangela utshintsho kwiipropati zerabha. I-oxidation yenye yezizathu ezibalulekileyo zokwaluphala kwerabha.
(b) Umsebenzi weekhemikhali we-ozone kunye ne-ozone uphezulu kakhulu kunoweoksijini, kwaye uyatshabalalisa ngakumbi. Kwakhona uyaphula uthotho lweemolekyuli, kodwa isiphumo se-ozone kwirabha siyahluka nokuba irabha ikhubazekile okanye ayiguqukanga. Xa isetyenziswa kwirabha ekhubazekileyo (ikakhulu irabha engagcwaliyo), imifantu ijonge kwicala lesenzo soxinzelelo, oko kukuthi, into ebizwa ngokuba yi-"ozone crack"; xa isetyenziswa kwirabha ekhubazekileyo, kuphela ifilimu ye-oxide eyenziwa phezu komphezulu ngaphandle kokuqhekeka.
(c) Ubushushu: Ukunyusa ubushushu kunokubangela ukuqhekeka kobushushu okanye ukudibana kwerabha ngobushushu. Kodwa isiphumo esisisiseko sobushushu kukusebenza. Phucula izinga lokusasazeka kweoksijini kwaye usebenze impendulo yeoksijini, ngaloo ndlela ukhawulezise izinga lempendulo yeoksijini yerabha, into eqhelekileyo yokwaluphala - ukuguga kweoksijini ngobushushu.
(d) Ukukhanya: Okukhona iliza lokukhanya lifutshane, kokukhona amandla eba maninzi. Umonakalo kwirabha yimitha ye-ultraviolet enamandla aphezulu. Ukongeza ekubangeleni ngokuthe ngqo ukuqhekeka kunye nokudibanisa ikhonkco le-molecular yerabha, imisebe ye-ultraviolet ivelisa ii-free radicals ngenxa yokufunxwa kwamandla okukhanya, okuqalisa kwaye kukhawulezise inkqubo yokusabela kwekhonkco le-oxidation. Ukukhanya kwe-Ultraviolet kusebenza njengokufudumeza. Olunye uphawu lwesenzo sokukhanya (esahlukileyo kwisenzo sobushushu) kukuba senzeka ikakhulu kumphezulu werabha. Kwiisampuli ezinomxholo ophezulu weglue, kuya kubakho imifantu yenethiwekhi kumacala omabini, oko kukuthi, okubizwa ngokuba yi-"optical outer layer cracks".
(e) Uxinzelelo lwe-mechanical: Phantsi kwesenzo esiphindaphindwayo soxinzelelo lwe-mechanical, uthotho lwee-molecular zerabha luya kwaphulwa ukuze luvelise ii-free radicals, eziya kubangela ukusabela kwe-oxidation chain kwaye zenze inkqubo ye-mechanochemical. Ukuqhekeka kwe-mechanical kwee-molecular chains kunye nokusebenza kwe-mechanical kweenkqubo ze-oxidation. Yeyiphi enesandla esiphezulu ixhomekeke kwiimeko apho ibekwe khona. Ukongeza, kulula ukubangela ukuqhekeka kwe-ozone phantsi kwesenzo soxinzelelo.
(f) Ukufuma: Isiphumo somswakama sinemiba emibini: irabha yonakala lula xa ivulwa yimvula emoyeni ofumileyo okanye intywiliselwa emanzini. Oku kungenxa yokuba izinto ezinyibilikayo emanzini kunye namaqela amanzi acacileyo kwirabha zikhutshwa kwaye zinyibilikiswe ngamanzi. Zibangelwa yi-hydrolysis okanye ukufunxwa. Ingakumbi phantsi kwesenzo esitshintshanayo sokuntywiliselwa emanzini kunye nokuvezwa emoyeni, ukutshatyalaliswa kwerabha kuya kukhawuleziswa. Kodwa kwezinye iimeko, ukufuma akulimazi irabha, kwaye kunefuthe lokulibazisa ukuguga.
(g) Ezinye: Kukho i-chemical media, ii-variable valence metal ions, i-high-energy radiation, umbane kunye ne-biology, njl.njl., ezichaphazela irabha.
3. Ziziphi iintlobo zeendlela zokuvavanya ukuguga zerabha?
Ingahlulwahlulwa ibe ziindidi ezimbini:
(a) Indlela yokuvavanya ukuguga yendalo. Yahlulwe ngakumbi yaba luvavanyo lokuguga olusemoyeni, uvavanyo lokuguga olukhawulezileyo olusemoyeni, uvavanyo lokuguga lwendalo lokugcina izinto, indlela yendalo (kubandakanya umhlaba ongcwatyiweyo, njl.njl.) kunye novavanyo lokuguga lwebhayoloji.
(b) Indlela yovavanyo lokwaluphala olukhawulezileyo okwenziwayo. Ukwaluphala okushushu, ukuguga nge-ozone, ukuguga ngefoto, ukuguga ngemozulu okwenziwayo, ukuguga ngefoto-ozone, ukuguga ngebhayoloji, imitha enamandla aphezulu kunye nokuguga ngombane, kunye nokwaluphala kweendaba zamakhemikhali.
4. Luluphi udidi lobushushu olufanele lukhethwe kuvavanyo lokuguga komoya oshushu kwiikhompawundi ezahlukeneyo zerabha?
Kwirabha yendalo, ubushushu bovavanyo buhlala buyi-50~100℃, kwirabha yokwenziwa, buhlala buyi-50~150℃, kwaye ubushushu bovavanyo kwiirabha ezithile ezikhethekileyo buphezulu. Umzekelo, irabha ye-nitrile isetyenziswa kwi-70~150℃, kwaye irabha ye-silicone fluorine isetyenziswa kwi-200~300℃. Ngamafutshane, kufuneka imiselwe ngokwesi sivivinyo.