Kunezinhlobo ezimbili zenjoloba: ezemvelo nezokwenziwa. Injoloba yemvelo ivela ku-latex, ubisi olunobisi olutholakala ezitshalweni zasezindaweni ezishisayo. Irabha yokwenziwa yenziwe nge-petroleum futhi ayiveli ezitshalweni.
Isingeniso: yini i-silicone nerabha yemvelo, futhi yimuphi umehluko oyinhloko?
Irabha yemvelo, evela ku-latex yesihlahla se-Hevea brasiliensis, ibiwumthombo oyinhloko wenjoloba kusukela yatholwa abahloli bamazwe base-Euro-American eNingizimu Melika ngekhulu le-16. I-Brazil yayingumphakeli omkhulu kwaze kwaba ngawo-1860 lapho amanye amazwe (ikakhulukazi iMalaysia ne-Indonesia) eqala ukukhiqizwa kwezihlahla zenjoloba ngobuningi. Njengamanje, injoloba yemvelo iseyimpahla ebalulekile futhi ilinganiselwa ezigidini eziyi-14 zokukhiqiza emhlabeni wonke ngo-2009. Amarabha okwenziwa athuthukiswa ekuqaleni kwawo-1900 ngempumelelo ehlukahlukene futhi kwaze kwaba yiMpi Yezwe II lapho akhiqizwa ngobuningi ukuze athathelwe indawo. iraba yemvelo ezinhlelweni eziningi. Irabha yokwenziwa ephumelela kakhulu i-poly(cis-1,4-isoprene), noma i-polyisoprene (IR), enezakhiwo zomzimba namakhemikhali ezifana kakhulu nalezo zenjoloba yemvelo.
Umlando
Ukusetshenziswa kokuqala kwerabha kwakungamasiko omdabu aseMesoamerica. Ubufakazi bokuqala bemivubukulo bokusetshenziswa kwedethi yenjoloba yemvelo kusiko lama-Olmec, ngesigameko ngendlela yamabhola. Injoloba yayisetshenziswa amasiko amaMaya nama-Aztec - ngaphezu kokwenza amabhola ama-Aztec asebenzisa irabha ukwenza imaski, izimbadada, nezinye izinto. Izici zokugxuma zenjoloba bezibalulekile emidlalweni yebhola yase-Mesoamerican efana ne-ulama, ebidlalwa abantu abangaba ngu-2,000. Ngo-1700 BCE ama-Olmec ayeseshintshile ekwenzeni izinto zenjoloba ukuze ayisebenzise njengendawo eqanjiwe yokudweba izithombe.
Irabha yemvelo i-elastomer etholakala ku-latex. Le polymer ayijwayelekile ngoba yakhiwe ngokuphelele (ngaphandle kokungavamile) kwe-cis-1,4-polyisoprene, ngaphandle kokungaguquguquki (okungukuthi, izibopho eziphindwe kabili) phakathi kwamaketanga amabili amakhulu aboshwe kuma-athomu aseduze eketango eliyinhloko. Amaketango ahlelwe ngokulungiselelwa okuthi “S” ngakunye (bona isithombe), okunikeza injoloba yemvelo ukunwebeka kwayo ebangeni elibanzi lokushisa ukusuka endaweni eqandisiwe ukuya cishe ku-170 °C (340 °F).
Production
Irabha ye-Silicone yenziwe ngama-polymer angaphili, noma ama-synthetic, kanti irabha yemvelo ivela ku-latex yezitshalo ezithile. Ngokwekhemikhali, irabha ye-silicone ihlukile kunerabha yemvelo ngenxa yokuba khona kwamaqembu e-methyl emaketangeni e-silicone kanti irabha yemvelo inamaqembu e-vinyl kuphela emaketangeni awo. Indawo yokwelapha yerabha ye-silicone nayo ihlukile kuneyerabha yemvelo. Izingosi zokwelapha ziyizindawo eziseceleni komgogodla we-polymer lapho ukuxhumanisa kungenziwa khona. Kumarabha e-silicone, i-thecnology isebenzisa ama-silane a-hydrolyzable njengezindawo zokwelapha, kuyilapho ubuchwepheshe benjoloba bemvelo busebenzisa ama-athomu esibabule njengendawo yokwelapha.
Irabha ye-Silicone iyi-elastomer engaphili eyakhiwe nge-silicon nomoya-mpilo. Yaziwa nangokuthi i-polysiloxane. Ngokungafani nerabha yemvelo, irabha ye-silicone ayinawo amabhondi aphindwe kabili emaketangeni ayo e-polymer. Lokhu kuyenza ingangenwa kalula yi-oxidation kanye nokonakala ngenxa yokushisa nokukhanya kwelanga. Irabha ye-Silicone nayo inephuzu lokuncibilika eliphakeme kunerabha yemvelo, okwenza ifaneleke kakhulu izinhlelo zokusebenza ezinokushisa okuphezulu.
Irabha yemvelo iyi-elastomer ephilayo eyakhiwe amayunithi e-isoprene. Inamabhondi aphindwe kabili emaketangeni ayo e-polymer, ayenza ibe lula ku-oxidation futhi yonakaliswe ukushisa nokukhanya kwelanga. Irabha yemvelo nayo inendawo encibilikayo ephansi kunerabha ye-silicone, iyenza ingalungeli kakhulu ukusetshenziswa kwezinga lokushisa eliphezulu.
Ukuqanjwa: ihlanganisani ngayinye yalezi rubha?
Ukwakhiwa kwe-Silicone Rubber
Irabha ye-Silicone yenziwe ngama-polymer ane-Si-O-Si backbones. Ngokungeziwe kulawa ma-polymers, irabha ye-silicone nayo iqukethe izithasiselo ezinjengama-filler, ama-pigment, kanye nemithi yokwelapha. Ukwakhiwa kwerabha ye-silicone kungenziwa ngokwezifiso ukuze kuzuzwe izakhiwo ezithile.
Iningi lama-silicone amarabha okuhweba afakwe engozini, okusho ukuthi aphathwe ngamakhemikhali noma ukushisa ukuze athuthukise izakhiwo zawo zomzimba. I-Vulcanization inika irabha ye-silicone ukumelana kwayo nezinga lokushisa eliphezulu futhi iyenza iqine ngokwengeziwe sekukonke.
Ukwakhiwa Kwerabha Yemvelo
Irabha yemvelo yenziwe ngama-polymer ane-Isoprene backbones. Lawa ma-polymer atholakala emanzini ezihlahla ezithile, ikakhulukazi isihlahla se-Hevea brasiliensis. Ukwakheka kwawo kwamangqamuzana kuwuchungechunge lwama-athomu ekhabhoni, anama-athomu e-hydrogen amaningana axhunywe emaketangeni. Lawa ma-athomu e-hydrogen yiwona enza irabha yemvelo ibe nokunwebeka. Inqubo efanayo (hydrogenation) isetshenziselwa ukwenza amarabha okwenziwa.
Izakhiwo: yiziphi izakhiwo ezibonakalayo abanazo?
Kunezici ezimbalwa ezibalulekile ezihlukanisa irabha ye-silicone nenjoloba yemvelo. Enye iwukuqina kwayo; Irabha ye-silicone ingakwazi ukumelana namazinga okushisa adlulele, ukukhanya kwe-UV, nokuchayeka kwe-Ozone ngaphandle kokuphuka, kuyilapho irabha yemvelo izowonakala ngokuhamba kwesikhathi ngaphansi kwalezi zimo. Ukwengeza, irabha ye-silicone imelana kakhulu namakhemikhali kunenjoloba yemvelo, okuyenza ibe ukukhetha okukhethwa kukho lapho ingase ihlangane namakhemikhali anokhahlo noma izincibilikisi. Okokugcina, irabha ye-silicone inokuminyana ephansi kakhulu kunenjoloba yemvelo, okusho ukuthi ilula ngesisindo futhi iyavumelana nezimo. Lezi zakhiwo zenza irabha ye-silicone ibe yinto efanelekile yezinhlelo zokusebenza eziningi zezimboni nezabathengi.
Irabha ye-Silicone iyi-elastomer eyakhiwe nge-silicone—yona ngokwayo i-polymer—equkethe i-silicon kanye ne-carbon, i-hydrogen, nomoya-mpilo. Irabha ye-Silicone inezinzuzo eziningi eziyenza ilungele ukusetshenziswa ezinhlelweni eziningi ezahlukene.
Ikwazi ukumelana nokushisa ngokwedlulele, okusho ukuthi ingamelana namazinga okushisa aphezulu ngaphandle kokwehliswa. Lokhu kuyenza ifaneleke ukusetshenziswa ezinhlelweni lapho kunobungozi bokulimala kokushisa, njengaku abicah ama-gaskets ezimoto kanye nama-sealants.
Irabha ye-Silicone nayo inokumelana okuhle kakhulu namazinga okushisa abandayo. Lokhu kuyenza ilungele ukusetshenziswa ezindaweni lapho kunobungozi bokulimala okubandayo, njengasezitsheni zokugcina ukudla.
Irabha ye-Silicone nayo iqinile kakhulu. Ayehlisi ngokuhamba kwesikhathi njengoba kwenza irabha yemvelo, okusho ukuthi inobude bempilo ende kakhulu. Lokhu kuyenza ifaneleke ukusetshenziswa ezinhlelweni lapho ukuthembeka kwesikhathi eside kubalulekile, njengakumadivayisi ezokwelapha.
Irabha yemvelo iyi-elastomer ekhishwa oketshezini olumhlophe oluyi-milky olubizwa ngokuthi i-latex olukhiqizwa izitshalo eziningi. Ibonisa izici ezinhle zemishini ezifana nokunwebeka, ukumelana nokuhuzuka, namandla aqinile kanye nokumelana namanzi okuhle kakhulu kanye nezakhiwo zokuvikela ugesi.
Umthelela wemvelo: hlobo luni lwezinyathelo abanazo?
Izinhlobo ezimbili eziyinhloko zenjoloba ziyi-silicone nerabha yemvelo. Zombili zinezinyathelo ezihlukene zemvelo.
Irabha yemvelo yenziwa ngobisi lwezihlahla ezithile, futhi iwumthombo ovuselelekayo. Ibhidliza kalula endaweni ezungezile futhi ayikhiphi ubuthi obuyingozi. Ukukhiqizwa kwenjoloba yemvelo kudinga umhlabathi omkhulu, okungaba nomthelela ongemuhle ezinhlelweni zemvelo.
Irabha ye-Silicone yenziwe ngezinto zokwenziwa futhi ayiyona insiza evuselelekayo. Ayiqhekeki kalula endaweni ezungezile futhi ingakhipha ubuthi obuyingozi. Ukukhiqizwa kwerabha ye-silicone akudingi inani elikhulu lomhlaba, kodwa izinto zokwenziwa ezenziwe ngazo zingaba yingozi emvelweni.
Izindleko: zibiza malini?
Izindleko zihlale ziyisici esibalulekile okufanele sicatshangelwe lapho ukhetha impahla yephrojekthi yakho. Ngakho-ke, kubiza malini ama-silicone namarabha emvelo?
Irabha ye-silicone ngokuvamile ibiza kakhulu kunerabha yemvelo. Lokhu kungenxa yokuthi irabha ye-silicone inokumelana nokushisa okungcono nokumelana namakhemikhali kunerabha yemvelo. Ngaphezu kwalokho, irabha ye-silicone ingakwazi ukumelana namazinga okushisa aphezulu kunerabha yemvelo, ikwenze kube ukukhetha okuthandwayo kwezinhlelo zokusebenza eziningi.
Irabha yemvelo, ngakolunye uhlangothi, ibiza kancane kunerabha ye-silicone. Lokhu kungenxa yokuthi irabha yemvelo ayimelani nokushisa namakhemikhali njengerabha ye-silicone. Kodwa-ke, irabha yemvelo ingasetshenziswa ezinhlobonhlobo zezinhlelo zokusebenza kunerabha ye-silicone ngenxa yezindleko zayo eziphansi.
Isiphetho: iyiphi irabha engcono iyonke?
Kokubili irabha ye-silicone nerabha yemvelo inobuhle nobubi bayo. Kuya ngezidingo zakho ezithile ukuthi iyiphi ezokusebenzela kangcono. Uma udinga impahla engakwazi ukumelana namazinga okushisa aphezulu, khona-ke irabha ye-silicone iyindlela yokuhamba. Uma udinga into enwebekayo futhi enamandla aqinile, khona-ke irabha yemvelo iyisinqumo esingcono. Ekugcineni, irabha engcono kakhulu yezidingo zakho incike ekutheni yiziphi izimfanelo ezibaluleke kakhulu kuwe.
