Yuav ua li cas txhawm rau txhim kho kev laus ntawm cov roj hmab foob?
Lub ntsiab hom kev laus ntawm cov roj hmab foob
Roj hmab foobKev laus yog hais txog cov txheej txheem ntawm kev ua haujlwm ntawm cov khoom siv roj hmab hauv kev ua haujlwm ntawm ib puag ncig (xws li lub teeb, cua sov, oxygen, ozone, mechanical stress, thiab lwm yam). Cov hom kev laus tseem ceeb muaj xws li:
Thermal-oxidative aging: Nyob rau hauv kev sib koom ua ke ntawm tshav kub thiab oxygen, cov roj hmab molecular saw undergoes oxidative degradation los yog cross-linking.
Ozone Aging: Ozone reacts nrog roj hmab ob daim ntawv cog lus, ua rau cov kab tawg (ozone tawg).
Yees duab: Ultraviolet rays ua rau photooxidative decomposition ntawm roj hmab molecules, ua dawb radicals kom aging.
Damp Thaum tshav kub kub laus: Nyob rau hauv ib qho chaw high humidity, dej vapor txhawb lub hydrolysis ntawm roj hmab los yog accelerates oxidation.
Mechanical aging: Dynamic stress thiab kev sib txhuam ua rau microcracks rau propagate, ntxiv accelerating aging.
Ib txoj hauv kev los txhim kho kev laus ntawm cov roj hmab
Kev xaiv cov khoom thiab formulation optimization
Xaiv hom ntawmroj hmab foobnrog zoo heev aging kuj:
Cov roj hmab uas muaj cov dej saturation siab: xws li hydrogenated nitrile butadiene roj hmab (HNBR), ethylene propylene roj hmab (EPDM), thiab fluoroelastomer (FKM), vim muaj cov saturation siab hauv cov qauv molecular, cov ntsiab lus tsis tshua muaj ob daim ntawv cog lus, thiab zoo dua oxidation thiab ozone kuj. .
Silicone roj hmab (SiR) yog qhov zoo tshaj plaws ntawm kev tiv thaiv tshav kub, ozone, thiab UV tab sis kuj tsis muaj zog ntawm kev tswj xyuas lub zog.
Recipe Design Optimization:
Filler: Nano muab tub lim (xws li nano-silica lossis nano calcium carbonate) lossis hloov cov pa roj carbon dub yog xaiv los txhim kho roj hmab lub zog thiab kev laus tiv thaiv.
Plasticizers: Xaiv cov plasticizers uas muaj kev ruaj ntseg zoo, xws li phthalates (DOA, DOP) los yog ib puag ncig tus phooj ywg plasticizers, kom tsis txhob muaj kev laus los ntawm plasticizer decomposition.
Kev sib txuas ntawm qhov sib txuas: Siv lub peroxide cross-linking system (xws li di-tert-butyl peroxide) es tsis txhob muaj sulfur cross-linking kom tsis txhob muaj teeb meem ntawm thermal thiab oxygen degradation ntawm vulcanized roj hmab.
Ntxiv cov tshuaj tiv thaiv kev laus
Tus neeg sawv cev tiv thaiv kev laus yog ib qho tseem ceeb rau kev txhim kho kev laus ntawm cov roj hmab foob. Feem ntau siv cov tshuaj tiv thaiv kev laus muaj xws li:
Antioxidant:
Antioxidants muaj xws li hydroquinone (BHT) thiab phosphite, uas tuaj yeem ntes cov dawb radicals thiab qeeb oxidant cov tshuaj tiv thaiv.
Ultraviolet absorbers, xws li benzophenones (UV-531) thiab parabens, nqus ultraviolet rays thiab hloov mus rau hauv tshav kub.
Hlau passivator: inhibits cov tshuaj tiv thaiv ntawm roj hmab nrog catalytically oxidized hlau ions.
Ozone inhibitors:
Paraffin wax (xws li microcrystalline paraffin): Tiv thaiv ozone los ntawm kev tsiv mus rau cov roj hmab saum npoo los tsim ib qho kev thaiv.
Cov tshuaj ozone inhibitors (piv txwv li, diphenylamines, amine antioxidants): hnov mob nrog ozone kom txo cov concentration ntawm ozone.
Co-stabilizers: Synergistically siv nrog antioxidants thiab UV absorbers los txhim kho kev tiv thaiv tag nrho.
Txhim kho cov txheej txheem ntau lawm
Kev tswj nruj ntawm vulcanization tej yam kev mob: Overvulcanization tuaj yeem ua rau muaj teeb meem kev laus ntawm cov roj hmab, thiab cov vulcanization kub thiab lub sij hawm yuav tsum tau optimized.
Kev sib xyaw ua ke: zam ntau dhau los yog tsawg dhau ntawm cov khoom hauv zos kom ntseeg tau tias cov tshuaj tiv thaiv kev laus yog sib npaug.
Txhim kho thermal oxidation hauv kev ua haujlwm: Txo cua sib cuag thaum lub sij hawm sib xyaw thiab vulcanization, txo qhov kev pheej hmoo ntawm oxidation.
Kev tiv thaiv nto
Txheej txheej: Siv cov tshuaj tiv thaiv kev laus (xws li polyurethane coatings, thiab silicon-oxygen coatings) rau cov khoom siv roj hmab los ua ib qho kev thaiv lub cev.
Txau cov dej tiv thaiv: Txau cov kua uas muaj cov tshuaj antioxidants kom ncua cov txheej txheem kev laus.
Txheej txheej: Hlau txheej lossis cov txheej txheem sib xyaw yog siv los txhim kho UV tiv thaiv.
Tswj ntawm ib puag ncig yam
Tiv thaiv los ntawm lub teeb: Txo UV hluav taws xob, xws li siv lub teeb tawm ntim lossis khaws cia hauv qhov tsaus ntuj.
Moisture-pov thawj: tswj lub ambient humidity kom tsis txhob ya raws thiab txhawb kev laus ntawm roj hmab.
Tsawg-kub cia: Khaws cov khoom siv roj hmab hauv qhov chaw uas muaj qhov kub thiab txias tuaj yeem ua rau qeeb qeeb ntawm kev laus.
Tsis txhob sib cuag nrog cov khoom nquag: Tsis txhob sib cuag nrog cov roj, cov kuab tshuaj organic, cov kua qaub, thiab alkalis, uas tuaj yeem ua rau cov roj hmab aging.