Hnub tim: 2022-05-28 Source: Fiber Composites

Lub lattice qauv ntawm lub zoo tagnrho graphite siv lead ua belongs rau lub hexagonal siv lead ua, uas yog ib tug multi-txheej overlapping qauv tsim ntawm carbon atoms nyob rau hauv ib tug rau-tus tswv cuab lub nplhaib network qauv. Nyob rau hauv lub nplhaib rau-tus tswv cuab, cov pa roj carbon atoms yog nyob rau hauv daim ntawv ntawm sp 2 hybrid.

Basic qauv

Lub lattice qauv ntawm lub zoo tagnrho graphite siv lead ua belongs rau lub hexagonal siv lead ua system, uas yog tsim los ntawm carbon atoms muaj li ntawm ib tug rau-tus tswv cuab lub nplhaib network qauv. Nyob rau hauv lub nplhaib rau-tus tswv cuab, cov pa roj carbon atoms yog sp 2 hybridization tshwm sim. Nyob rau hauv sp2 hybridization, muaj 1 2s electron thiab 2 2p electron hybridization, tsim peb sib npaug o muaj zog daim ntawv cog lus, daim ntawv cog lus nrug yog 0.1421nm, qhov nruab nrab daim ntawv cog lus zog yog 627kJ / mol thiab cov ces kaum yog 120 ib leeg.

Cov ntshiab 2p orbitals nyob rau hauv tib lub dav hlau yog perpendicular rau lub dav hlau uas peb o daim ntawv cog lus nyob, thiab cov N-bonds ntawm cov pa roj carbon atoms uas ua rau lub N-bond yog parallel rau ib leeg thiab sib tshooj los ua ib tug loj N. - daim ntawv cog lus; Cov hluav taws xob tsis nyob hauv zos ntawm n electron tuaj yeem txav mus los ntawm lub dav hlau, muab nws cov khoom siv hluav taws xob. Lawv tuaj yeem nqus pom lub teeb, ua graphite dub. Lub van der Waals quab yuam ntawm cov graphite txheej yog deb tsawg tshaj li valence bond force nyob rau hauv cov khaubncaws sab nraud povtseg. Qhov sib nrug ntawm cov khaubncaws sab nraud povtseg yog 0.3354nm, thiab lub zog daim ntawv cog lus yog 5.4kJ / mol. Cov graphite txheej yog staggered los ntawm ib nrab ntawm lub hexagonal symmetry thiab rov ua dua nyob rau hauv txhua lwm yam txheej, tsim ABAB..

Structure [4], thiab endowing nws tus kheej-lubrication thiab interlayer muaj peev xwm sab hauv, raws li qhia nyob rau hauv daim duab 2-5. Cov pa roj carbon fiber ntau yog microcrystalline pob zeb-cov ntaub ntawv tau los ntawm cov organic fiber los ntawm carbonization thiab graphitization.

Lub microstructure ntawm carbon fiber zoo ib yam li cov khoom graphite, uas belongs rau cov qauv ntawm polycrystalline chaotic graphite. Qhov sib txawv ntawm cov qauv graphite nyob rau hauv qhov tsis raug txhais lus thiab kev sib hloov ntawm cov atomic txheej (saib daim duab 2-6). Lub rau lub ntsiab network covalent daim ntawv cog lus yog khi nyob rau hauv lub atomic txheej ntawm - uas yog yeej nyob rau hauv parallel mus rau lub fiber axis. Yog li ntawd, nws yog feem ntau ntseeg tias carbon fiber yog tsim los ntawm ib tug teeb meem graphite qauv raws qhov siab ntawm lub fiber axis, uas ua rau ib tug heev axial tensile modulus. Cov qauv lamellar ntawm graphite muaj qhov tseem ceeb anisotropy, uas ua rau nws lub cev muaj zog kuj qhia anisotropy.

Properties thiab kev siv ntawm carbon fiber

Cov pa roj carbon fiber ntau tuaj yeem muab faib ua filament, staple fiber, thiab staple fiber. Cov khoom siv kho tshuab tau muab faib ua hom dav dav thiab hom kev ua haujlwm siab. Lub zog carbon fiber ntau yog 1000 MPa, lub modulus yog li 10OGPa. High-performance carbon fiber yog muab faib ua hom siab zog (lub zog 2000MPa, modulus 250GPa) thiab cov qauv siab (modulus saum 300GPa). Lub zog ntau dua 4000MPa tseem hu ua ultra-siab zog hom; Cov uas muaj ib qho modulus ntau dua 450GPa yog hu ua ultra-high qauv. Nrog rau txoj kev loj hlob ntawm aerospace thiab aviation kev lag luam, siab zog thiab siab elongation carbon fiber tau tshwm sim, thiab nws elongation yog ntau tshaj 2%. Qhov loj yog polypropylene qhov muag PAN-raws li carbon fiber. Cov pa roj carbon fiber ntau muaj zog axial thiab modulus, tsis muaj creep, zoo qaug zog tsis kam, tshwj xeeb kub thiab hluav taws xob conductivity ntawm cov hlau tsis muaj hlau thiab hlau, me me coefficient ntawm thermal expansion, zoo corrosion kuj, tsis tshua muaj fiber ntau ntom, thiab zoo X-ray kis tau tus mob. Txawm li cas los xij, nws cov kev cuam tshuam tsis zoo thiab yooj yim rau kev puas tsuaj, oxidation tshwm sim nyob rau hauv qhov kev txiav txim ntawm cov kua qaub, thiab hlau carbonization, carburization, thiab electrochemical corrosion tshwm sim thaum nws ua ke nrog hlau. Yog li ntawd, carbon fiber yuav tsum tau kho saum npoo ua ntej siv.