Isingeniso kuMechanism Evimbela Umlilo Yezingxenye Zepulasitiki Zesiphetho Zokuvikela
Umphumela wokuvimbela ilangabi wezingxenye zepulasitiki awuyona into eyodwa, kodwa udlala indima ezigabeni ezahlukene zokusha (ukushisa, ukubola, ukusha, ukusabalala) ngezindlela zomzimba nezamakhemikhali. Izindlela eziyinhloko zingahlukaniswa ngezinhlobo ezilandelayo:
1. Indlela yokuvimbela ilangabi lesigaba segesi (ukubamba ama-free radicals)
Lena enye yezindlela ezibaluleke kakhulu nezisebenza kahle.
Isimiso: Uma izinto ezivimbela ilangabi zibola ngokushisa, zingakhipha izinto ezisebenzayo (njenge-halogen radicals X·), ezizobamba ama-radical e-H· kanye ne-HO· (iqembu le-hydroxyl) agcina ukusabela kweketanga lomlilo ekusabeleni kokushisa, ukuze ukuhlushwa kwawo kwehle kakhulu, ukuze kuphazamise ngempumelelo ukusabela kwamakhemikhali kokushisa.
Izinto ezivimbela ilangabi ezijwayelekile:
Izinto ezivimbela ilangabi le-halogen (i-bromine, i-chlorine): ukusebenza kahle okuphezulu, kodwa intuthu enkulu ngesikhathi sokusha, ingakhiqiza amagesi anobuthi abhubhisayo (ama-dioxin, njll.), okwamanje anqunyelwe kwezinye izinkambu ezinezidingo eziphezulu zokuvikela imvelo.
Izinto ezivimbela ilangabi ezingenayo i-halogen (ezifana ne-nitrogen, izinto ezivimbela ilangabi ezingaphakathi kwe-phosphorus-nitrogen): Amagesi angashi njenge-ammonia, i-nitrogen, kanye nomhwamuko wamanzi akhiqizwa ngokubola, ukuxuba umoya-mpilo kanye nokugcwala kwamagesi ashayo, kuyilapho futhi ebamba ama-free radical.
2. Indlela yokuvimbela ilangabi lesigaba esijiyile (ukwakheka kwengqimba yekhabhoni)
Isimiso: Izinto ezivimbela ilangabi zingakhuthaza ukuphelelwa amanzi emzimbeni kanye nokufakwa kwe-carbon kuma-polymer ebusweni belangabi, zakha ungqimba lwekhabhoni oluqinile nolunezimbobo. Lolu ngqimba lwekhabhoni ludlala izindima eziningi:
Ukushisa: Kuvimba ukudluliselwa kokushisa kwangaphandle ku-polymer yangaphakathi.
Isithiyo se-oksijini: vimbela imikhiqizo yokubola yangaphakathi ukuthi ingaphumi, futhi futhi ihlukanise i-oksijini yangaphandle ukuthi ingangeni.
Isendlalelo sesithintelo: Sivikela izinto ezingaphansi emaconsini ancibilikayo.
Izinto ezivimbela ilangabi ezijwayelekile:
Izinto ezivimbela ilangabi le-phosphorus: njenge-phosphate esters, i-phosphorus ebomvu. i-phosphoric acid kanye ne-polymetaphosphosphic acid kwakheka ukushisa, okukhuthaza ukuphelelwa amanzi kwama-polymers ane-oxygen (njenge-PC kanye ne-PET) abe yi-carbon.
Uhlelo oluvimbela ilangabi olungaphakathi (IFR): Lwakhiwe umthombo we-asidi, umthombo wekhabhoni kanye nomthombo wegesi. Uma lufudunyezwa, luyaphopha futhi lunwebeke, lwakha ungqimba lwekhabhoni olunezimbobo olukhulu ngokuphindwe kaningi kunobukhulu bokuqala, olunomphumela omuhle kakhulu wokuvimbela ukushisa kanye nomphumela wokuvimbela umoya-mpilo, futhi luwubuchwepheshe obujwayelekile bokuvimbela ilangabi olungenalo i-halogen ephezulu.
3. Indlela yokupholisa (ukupholisa kwe-endothermic)
Isimiso: Ezinye izinto ezivimbela ilangabi zimunca ukushisa okuningi (ukumuncwa kokushisa okuphezulu) lapho zibola, ngaleyo ndlela zinciphise izinga lokushisa lobuso bezinto ezibonakalayo futhi zilibazise inqubo yokubola kokushisa kwama-polymer.
Izinto ezivimbela ilangabi ezijwayelekile:
Ama-hydroxide ensimbi: Asetshenziswa kakhulu yi-aluminium hydroxide (ATH) kanye ne-magnesium hydroxide (MH). Amunca ukushisa okuningi njengoba ebola futhi ekhipha umhwamuko wamanzi, anciphise amagesi avuthayo kanye nomoya-mpilo. Lena yindlela enobungani nemvelo, engenamusi, kodwa idinga inani elikhulu lokwengeza (ngokuvamile > 50%), okungathinta izakhiwo zemishini kanye nokugeleza kokucubungula kwezinto.
4. Amaconsi nemiphumela yokuxuba
Umphumela wamaconsi: Ezinye izinto (njenge-PA6/PA66 engagcini ilangabi) ziyancibilika futhi ziconse ngokushesha uma zishiswa, zithwale ukushisa ngaleyo ndlela zivikele izinto ezingenhla. Kodwa lokhu akulawuleki futhi kuyingozi ngoba amaconsi ancibilikisiwe angathwala amalangabi ukuze avuthe ezinye izingxenye. Uhlelo oluhle lokuvimbela ilangabi kufanele lucindezele amaconsi, noma luwenze angavuthi (amaconsi alinganiselwe avunyelwe ebangeni V-2, futhi anqunyelwe ebangeni V-0).
Umphumela wokuxuba: Ukubola kwezinto ezivimbela ilangabi kukhiqiza amagesi angashi (njengomhwamuko wamanzi, i-CO₂, i-N₂, i-NH₃, njll.), okunciphisa ukugcwala kwamagesi ashayo nomoya-mpilo ozungeze izinto.