1. Daim ntawv thov Scope
(1). Siv rau unsaturated roj hmab: xws li NR, BR, NBR, IR, SBR, thiab lwm yam.
(2). Siv rau cov roj hmab saturated: xws li EPM tsuas yog vulcanized los ntawm peroxide, EPDM tuaj yeem vulcanized los ntawm peroxide thiab sulfur.
(3). Siv rau lwm yam saw roj hmab: xws li Q vulcanization.
2. Cov yam ntxwv ntawm peroxide vulcanization system
(1). Lub network qauv ntawm cov roj hmab vulcanized yog CC daim ntawv cog lus, nrog lub zog siab zog, siab tshuaj lom neeg ruaj khov, thiab zoo heev tiv thaiv thermal thiab oxygen aging.
(2). Vulcanized roj hmab muaj tsawg deformation, zoo elasticity thiab tsis zoo dynamic kev ua tau zoo.
(3). Ua tsis zoo kev nyab xeeb thiab kim peroxide.
(4). Nyob rau hauv static sealing los yog kub static sealing khoom muaj ntau yam kev siv.
3. Feem ntau siv peroxides
Feem ntau siv cov tshuaj peroxide vulcanizing yog alkyl peroxides, diacyl peroxides (dibenzoyl peroxide (BPO)) thiab peroxy esters. Ntawm lawv, dialkyl peroxides tau siv dav. Xws li: diisopropyl peroxide (DCP): yog tam sim no feem ntau siv cov vulcanizing tus neeg sawv cev.
2,5-dimethyl-2,5-(di-tert-butylperoxy) hexane: tseem hu ua bis-dipentyl
4. Peroxide vulcanization mechanism
Cov pab pawg peroxide ntawm peroxide yog yooj yim decomposed los ntawm tshav kub los tsim cov dawb radicals, uas ua rau cov dawb radical hom cross-linking cov tshuaj tiv thaiv ntawm roj hmab molecular saw.
5. Cov ntsiab lus tseem ceeb ntawm peroxide vulcanization:
(1). Dosage: sib txawv nrog ntau hom roj hmab sib txawv
Kev sib txuas ntawm kev sib txuas ntawm peroxide: 1g molecule ntawm cov organic peroxide tuaj yeem ua kom muaj pes tsawg grams ntawm cov roj hmab molecules tsim cov tshuaj sib txuas sib txuas.
Piv txwv li: qhov cross-linking efficiency ntawm SBR yog 12.5; Kev sib txuas ntawm kev sib txuas ntawm BR yog 10.5; Kev sib txuas ntawm kev sib txuas ntawm EPDM, NBR, NR yog 1; Kev sib txuas ntawm kev sib txuas ntawm IIR yog 0.
(2). Kev siv tus neeg sawv cev nquag thiab tus neeg sawv cev co-sulfurizing los txhim kho kev sib txuas ntawm kev sib txuas
Lub luag haujlwm ntawm ZnO yog txhawm rau txhim kho cov cua sov ntawm cov nplaum, tsis yog cov activator. Lub luag haujlwm ntawm stearic acid yog txhim kho cov solubility thiab dispersion ntawm ZnO hauv cov roj hmab. HVA-2 (N, N'-phthalimido-dimaleimide) kuj yog ib qho kev ua kom zoo ntawm peroxide.
Ntxiv auxiliary vulcanizing tus neeg saib xyuas: feem ntau yog sulfur daj, thiab lwm yam auxiliary cross-linking agents xws li divinylbenzene, trialkyltricyanate, unsaturated carboxylates, thiab lwm yam.
(3). Ntxiv ib qho me me ntawm cov tshuaj alkaline, xws li MgO, triethanolamine, thiab lwm yam, txhawm rau txhim kho kev ua haujlwm ntawm kev sib txuas, tsis txhob siv cov pa roj carbon dub thiab silica thiab lwm cov kua qaub (acid ua kom dawb radicals passivation); antioxidants feem ntau yog amine thiab phenolic antioxidants, kuj yooj yim ua kom dawb radicals passivation, txo cov kev ua tau zoo ntawm kev sib txuas, yuav tsum tau siv sparingly.
(4). Vulcanization kub: yuav tsum siab tshaj qhov decomposition kub ntawm peroxide
(5). Vulcanization sij hawm: feem ntau 6 ~ 10 npaug ntawm ib nrab-lub neej ntawm peroxide.
Peroxide ib nrab-lub neej: ntawm qhov kub thiab txias, peroxide decomposition mus rau ib nrab ntawm qhov tseem ceeb ntawm lub sijhawm xav tau, qhia hauv t1/2.
Yog hais tias ib nrab-lub neej ntawm DCP ntawm 170 ℃ yog 1min, ces nws zoo sulphation lub sij hawm yuav tsum yog 6 ~ 10min.
Formulation piv txwv: EPDM 100 (base)
S 0.2 (tus neeg saib xyuas vulcanizing)
SA 0.5 (Activator)
ZnO 5.0 (los txhim kho cov cua sov)
HAF 50 (tus neeg sawv cev txhawb nqa)
DCP 3.0 (Thixotropic tus neeg sawv cev)
MgO 2.0 (Txhim kho kev sib txuas ua haujlwm)
Kev khiav hauj lwm roj 10 (softening agent)
