Qhov tsis zoo ntawm fluoroelastomer (FKM) yog qhov tsis zoo ntawm qhov kub thiab txias. Qhov ntsuas kub qis qis (TR10) ntawm binary FKM feem ntau yog -18 txog -16 ℃, thiab iav hloov pauv kub (Tg) yog -20 ℃; Qhov ntsuas kub qis ntawm ternary FKM tsis zoo dua li ntawm binary FKM. Tshwj xeeb uas tsis tshua muaj kub hom FKM muaj qhov kub thiab txias tsis kam, tab sis tus nqi siab heev.
FKM nyob rau hauv ASTM D 2000-2012 'automotive roj hmab cov khoom txheem faib system' ntawm M2, M5, M6 qib cov khoom yuav tsum tau kom dhau lub low-temperature embrittlement F15 (-25 ℃), M4 qib cov khoom yuav tsum tau mus dhau lub low-temperature embrittlement.-40 ℃ (F17) Nyob rau hauv xyoo tas los no, ntau thiab ntau FKM cov khoom yuav tsum tau ua kom tau raws li qhov yuav tsum tau ntawm ob qho tib si kub tsis kam (250-275 ℃) thiab kub kub embrittlement F15 los yog F17. Qhov zoo tshaj plaws yog siv FKM qhov kub thiab txias, xws li brittleness kub ntawm -45 ~ -40 ℃ Viton GLT hom FKM, tab sis qhov no FKM kub-kub kev ua tau zoo tsis zoo thiab tus nqi yog qhov nyuaj rau kev ua lag luam. Los ntawm kev txhim kho cov kev ua tau zoo ntawm binary FKM cov tebchaw tuaj yeem ua tau raws li qhov yuav tsum tau ua ntawm qhov ntsuas kub thiab txias, thiab tus nqi kuj tsim nyog, tau dhau los ua qhov kub ntawm kev tshawb fawb.
Daim ntawv no tshuaj xyuas tus yam ntxwv ntawm FKM qhov kub thiab txias ua haujlwm ntawm Tg, TR10 thiab brittleness kub (Tbri) ntawm kev sib raug zoo ntawm cov tub ntxhais kawm ntawv qib siab, muab tub lim, cov txheej txheem sib xyaw, thiab lwm yam.
1. Cov yam ntxwv ntawm FKM low-temperature embrittlement properties
Roj hmab muaj qhov rov qab deformation, tuaj yeem tsim cov deformation loj nyob rau hauv qhov kev txiav txim ntawm lub zog me me, thiab tuaj yeem rov qab los rau nws lub xeev qub tom qab tshem tawm cov quab yuam sab nraud, yog li nws tau siv dav. Txawm li cas los xij, raws li qhov kub thiab txias, qhov elasticity ntawm roj hmab maj mam deteriorates, thiab thaum nws ncav cuag Tg, cov roj hmab poob nws elasticity thiab tsis. Vim muaj ntau yam khoom siv roj hmab, nyob rau hauv cov txheej txheem ntawm kev siv yuav raug cuam tshuam, nro, shear, torsion, extrusion, abrasion, thiab lwm yam., nws cov low-temperature embrittlement kev ua tau zoo yuav tsum yog raws li nws cov kev ua haujlwm los xaiv txoj kev xeem tsim nyog. Feem ntau siv cov txheej txheem kev ntsuas qhov ntsuas kub tsis tshua muaj xws li Tg xeem, cuam tshuam qhov ntsuas kub ntawm qhov ntsuas kub, ntsuas qhov ntsuas kub qis, ntsuas qhov ntsuas kub tsis tshua muaj zog torsional rigidity (Gimen test), tsis kam ncab thiab txias coefficient xeem, ntsuas kub tsis tshua muaj zog, ntsuas kub qis compression mus tas li deformation thiab kev ntsuas kev ntxhov siab, thiab lwm yam.
Qhov kub tsis kam ntawm FKM tuaj yeem ua tus cwj pwm los ntawm Tg, Tbri, TR10 thiab Torsion Temperature ntawm qhov kub thiab txias (TGem), thiab lwm yam. Cov kev ntsuas no muaj ntau lub ntsiab lus tab sis muaj qee yam kev sib raug zoo.
(1) Tg yog qhov kub thiab txias uas cov roj hmab hloov los ntawm lub xeev siab heev mus rau lub xeev iav thiab lub xeev iav mus rau lub xeev siab heev, uas feem ntau ua rau lub zog ntawm cov roj hmab molecular chains.
(2) Tbri yog qhov kub thiab txias uas tsis muaj kev puas tsuaj rau cov roj hmab raws li cov xwm txheej ntawm kev cuam tshuam quab yuam deformation, uas feem ntau qhia txog lub zog ntawm cov roj hmab rau kev siv ntawm qhov kub thiab txias thiab nws muaj peev xwm tiv taus kev puas tsuaj.
(3) TR10 yog siv los ntsuas cov viscoelasticity thiab crystallization ntawm cov roj hmab ntawm qhov kub thiab txias, thiab feem ntau qhia txog qhov kub qis tshaj plaws uas cov khoom siv roj hmab tuaj yeem tswj nws cov elastic rov qab.
(4) TGem siv lub torsional steel hlau nrog ib tug paub torsional tas li raws li cov ntaub ntawv siv los ntswj cov qauv ntawm lub kaum sab xis loj, thaum qhov kub thiab txias, lub modulus ntawm cov roj hmab nce, lub rigidity nce, thiab lub kaum sab xis ntawm torsion txo mus rau qhov chaw uas nws NW nyuam qhuav twists ntawm Tg. Lub torsion lub kaum sab xis ntawm cov roj hmab raws li qhov kub thiab txias tuaj yeem ntsuas nws qhov kev ua tau zoo ntawm qhov kub thiab txias, feem ntau cuam tshuam qhov kub qis tshaj plaws uas cov roj hmab tuav nws elasticity.
2 FKM Tg, TR10 thiab kev sib raug zoo ntawm Tbri
Feem ntau siv FKM qis-kub embrittlement kev ua tau zoo tsis yog Tg, TR10 thiab Tbri, tus neeg muag khoom feem ntau siv qhov ntsuas Tg thiab TR10, ASTM txais qhov ntsuas ntsuas Tbri, muaj qee qhov sib txawv thiab kev sib raug zoo ntawm peb.
2. 1 Kev sib raug zoo ntawm Tg thiab TR10
TR10 ntawm txhua qib ntawm FKM yog nyob ze rau Tg (qhov sib txawv tsis ntau tshaj 3 ℃), qhia tias ob qho tib si Tg thiab TR10 tuaj yeem cuam tshuam qhov ntsuas kub qis thiab iav lub xeev kub ntawm cov roj hmab molecular saw.
2.2 Kev sib raug zoo ntawm FKM cov ntsiab lus fluorine thiab qis-kub embrittlement zog
Hauv kev sib piv binary thiab ternary FKM, TR10 nce nrog qhov nce ntawm cov ntsiab lus fluorine; thaum lub thib plaub monomer, PMVE, tau qhia, nws cov ntsiab lus muaj kev cuam tshuam zoo rau TR10.
Nws cov ntsiab lus muaj kev cuam tshuam zoo rau TR10. Txawm hais tias qhov nce ntawm cov ntsiab lus fluorine tuaj yeem txhim kho qhov kev txwv siab ntawm FKM siv qhov kub thiab txias, tab sis tib lub sijhawm, vim CF daim ntawv cog lus hloov CH daim ntawv cog lus, txo qhov softness ntawm cov saw molecular thiab qhov kub thiab txias ua haujlwm ntawm cov roj hmab.
2.3 Kev cuam tshuam ntawm cov fillers ntawm qhov kub thiab txias embrittlement zog ntawm FKM compounds
Cov pa roj carbon dub N774 nplaum muaj qhov qis tshaj Tbri thiab qhov zoo tshaj plaws kub-kub kuj; zinc oxide nplaum muaj qhov siab tshaj plaws Tbri thiab qhov tsis zoo ntawm qhov kub thiab txias; qhov qis-kub embrittlement kev ua tau zoo ntawm tsib hom adhesives tsis txawv ntau. Tom qab kev soj ntsuam, tom qab ntxiv cov fillers sib txawv, qhov sib txawv thiab cov qauv ntawm FKM molecular chains txawv, thiab qhov sib xws ntawm qhov kub thiab txias embrittlement kev ua tau zoo sib txawv.
Tom qab kev soj ntsuam, tom qab ntxiv cov fillers sib txawv, qhov khoob thiab cov qauv ntawm FKM molecular chains txawv, thiab cov khoom sib xws ntawm qhov kub thiab txias yog qhov sib txawv, thiab cov muab tub lim nrog ib qho me me ntawm cov roj hmab muaj cov ntsiab lus gel loj dua thiab zoo dua qhov kub thiab txias.
2.4 Cov nyhuv ntawm cov txheej txheem sib xyaw rau ntawm qhov kub thiab txias embrittlement zog ntawm FKM compounds
Cov txheej txheem sib xyaw kuj tseem muaj qhov cuam tshuam rau qhov kub-kub embrittlement ntawm FKM compounds. Plasticizing ua ntej sib tov tuaj yeem tau txais cov roj hmab molecule yooj yim dua
Qhov kub tsis kam ntawm qhov sib xyaw tuaj yeem txhim kho los ntawm plasticizing ua ntej sib tov. Nyias hla kev kho mob tom qab qhov chaw nres tsheb tuaj yeem txhim kho cov khoom tawg ntawm cov fillers thiab compatibilizers, thiab txhim kho qhov kub tsis kam. Feem ntau hais lus, qhov ntev molding, qhov qis dua Mooney viscosity ntawm cov roj hmab. Kev nce lub sijhawm molding yuav txo Tg ntawm cov roj hmab, tab sis qhov tshwm sim tsis tseem ceeb, thiab tsis muaj qhov sib txawv ntawm Tg thiab Tbri ntawm FKM roj hmab nrog ntau lub sijhawm molding.
3 Kev xaus
(1) Lub Tg ntawm FKM yog ze rau ntawm TR10, uas tuaj yeem cuam tshuam qhov kub tsis tshua muaj txav ntawm FKM molecular saw thiab iav lub xeev kub, thiab Tbri qis dua li ntawm Tg thiab TR10.
qis dua Tg thiab TR10.
(2) Qhov kub tsis tshua muaj embrittlement cov cuab yeej ntawm peroxide sulfurized siab fluorine FKM yog qhov zoo dua, thiab qhov kub thiab txias embrittlement khoom ntawm bisphenol binary sulfurized FKM yog qhov phem dua.
(3) FKM roj hmab uas muaj cov pa roj carbon dub N774 muaj qhov zoo dua qhov kub thiab txias; roj hmab nrog ib qho me me ntawm cov muab tub lim muaj cov ntsiab lus gel ntau dua thiab zoo dua qhov ntsuas kub tsis kam.
(4) Tus naj npawb ntawm molding lub sij hawm muaj me ntsis cuam tshuam rau cov khoom uas tsis kub-kub embrittlement ntawm FKM tebchaw.
