Silika yonyowandi chinthu chofunikira kwambiri chodzaza mphamvu mumakampani opanga rabala. Makhalidwe ake osiyanasiyana amakhudza kukana kwa rabala mwa njira ina kapena mwachindunji kukana kwa mkanda mwa kusintha kuyanjana kwa interfacial ndi matrix ya rabala, kufalikira, ndi mawonekedwe a makina a rabala. Pansipa, kuyambira pa makhalidwe ofunikira, tisanthula mwatsatanetsatane njira zawo zomwe zimakhudzira kukana kwa mkanda:
1. Malo Odziwika Pamwamba (BET)
Malo enieni a pamwamba ndi amodzi mwa makhalidwe ofunikira kwambiri a silica, omwe amawonetsa mwachindunji malo ake okhudzana ndi mphira ndi mphamvu yolimbitsa, zomwe zimakhudza kwambiri kukana kukwawa.
(1) Mphamvu Yabwino: Pakati pa mtunda winawake, kuwonjezera malo enaake (monga 100 m²/g mpaka 200 m²/g) kumawonjezera malo olumikizirana pakati pa silica ndi rabara. Izi zitha kuwonjezera mphamvu yolumikizirana pakati pa rabara kudzera mu "mphamvu yolumikizirana," zomwe zimapangitsa kuti rabara isasinthe komanso isamagwire bwino ntchito. Pakadali pano, kuuma kwa rabara, mphamvu yokoka, ndi mphamvu yong'ambika zimawonjezeka. Pakuwonongeka, silitha kugawanika mosavuta chifukwa cha kupsinjika kwambiri kwapafupi, zomwe zimapangitsa kuti pakhale kusintha kwakukulu pakukana kukanda.
(2) Mphamvu yoipa: Ngati malo enieniwo ndi akulu kwambiri (monga kupitirira 250 m²/g), mphamvu za van der Waals ndi mgwirizano wa haidrojeni pakati pa tinthu ta silika zimakula, zomwe zimapangitsa kuti kusonkhana kwa zinthu kukhale kosavuta (makamaka popanda kukonza pamwamba), zomwe zimapangitsa kuti kufalikira kwa zinthu kuchepe kwambiri. Ma agglomerate amapanga "malo opsinjika maganizo" mkati mwa rabara. Pakuwonongeka, kusweka kumachitika makamaka mozungulira ma agglomerate, m'malo mwake kumachepetsa kukana kwa kukwawa.
Pomaliza: Pali malo abwino kwambiri okhala ndi malo okwana 150-220 m²/g, omwe amasiyana malinga ndi mtundu wa rabara) pomwe kufalikira ndi kulimbitsa kumakhala koyenera, zomwe zimapangitsa kuti pakhale kukana kwabwino kwa kukwawa.
2. Kukula kwa Tinthu ndi Kukula kwa Tinthu
Kukula kwa tinthu tating'onoting'ono (kapena kukula kwa tinthu tating'onoting'ono) ndi kufalikira kwa silika mwanjira ina zimakhudza kukana kwa mikwingwirima mwa kusintha kufanana kwa kufalikira ndi kuyanjana kwa nkhope.
(1) Kukula kwa Tinthu: Kukula kwa tinthu tating'onoting'ono (nthawi zambiri kumagwirizana bwino ndi malo enaake) kumafanana ndi madera akuluakulu komanso mphamvu zolimbitsa (monga pamwambapa). Komabe, kukula kwa tinthu tating'onoting'ono kwambiri (monga kukula kwa tinthu tating'onoting'ono toyambira < 10 nm) kumawonjezera kwambiri mphamvu ya agglomeration pakati pa tinthu tating'onoting'ono, zomwe zimawonjezera kwambiri kufalikira kwa tinthu tating'onoting'ono. M'malo mwake, izi zimapangitsa kuti pakhale zolakwika za m'deralo, zomwe zimachepetsa kukana kwa kukwawa.
(2) Kugawa kwa Tinthu: Silika yokhala ndi tinthu tating'onoting'ono tomwe timafalikira imafalikira mofanana mu rabara, kupewa "malo ofooka" opangidwa ndi tinthu tating'onoting'ono (kapena ma agglomerates). Ngati kugawako kuli kwakukulu kwambiri (monga, komwe kuli tinthu ta 10 nm ndi kupitirira 100 nm), tinthu tating'onoting'ono tomwe timayamba kusweka (makamaka timawonongeka tikamasweka), zomwe zimapangitsa kuti tipewe kusweka.
Pomaliza: Silika yokhala ndi tinthu tating'onoting'ono (tofanana ndi malo enieni) komanso kufalikira kochepa ndi kothandiza kwambiri pakuwonjezera kukana kwa mikwingwirima.
3. Kapangidwe (Mtengo Woyamwa wa DBP)
Kapangidwe kake kamasonyeza kuuma kwa nthambi za silica aggregates (komwe kumafotokozedwa ndi DBP absorption value; mtengo wake wapamwamba umasonyeza kapangidwe kake kapamwamba). Zimakhudza kapangidwe ka netiweki ya mphira ndi kukana kusintha.
(1) Mphamvu Yabwino: Silika yokhala ndi kapangidwe kakakulu imapanga nthambi zokhala ndi magawo atatu, zomwe zimapangitsa kuti "network ya mafupa" ikhale yolimba mkati mwa rabala. Izi zimawonjezera kulimba kwa rabala komanso kukana kupsinjika. Pa nthawi yokanda, netiweki iyi imatha kuletsa mphamvu zakunja, kuchepetsa kutopa komwe kumachitika chifukwa cha kusintha mobwerezabwereza, potero kumawonjezera kukana kwa kukanda.
(2) Mphamvu yoipa: Kapangidwe kake kochuluka kwambiri (kuyamwa kwa DBP > 300 mL/100g) kumayambitsa kusakanikirana pakati pa zinthu za silica. Izi zimapangitsa kuti Mooney azitha kukhuthala kwambiri panthawi yosakaniza mphira, kuyenda bwino kwa zinthu, komanso kufalikira kosagwirizana. Malo okhala ndi zinthu zokhuthala kwambiri m'deralo adzawonongeka mofulumira chifukwa cha kupsinjika maganizo, m'malo mwake kuchepetsa kukana kwa kukwawa.
Pomaliza: Kapangidwe kapakati (kamene ka DBP kamayamwa 200-250 mL/100g) ndikoyenera kwambiri pokonza bwino komanso kukana kukwawa.
4. Zomwe zili pamwamba pa Hydroxyl (Si-OH)
Magulu a silanol (Si-OH) pamwamba pa silika ndi ofunikira kwambiri pakusintha momwe amagwirizanirana ndi rabara, zomwe zimakhudza kukana kwa kukwawa kudzera mu mphamvu yolumikizirana pakati pa nkhope.
(1) Osachiritsidwa: Kuchuluka kwa hydroxyl (> magulu 5/nm²) kumabweretsa kuuma kwa tinthu tating'onoting'ono kudzera mu mgwirizano wa hydrogen, zomwe zimapangitsa kuti tisabalalike bwino. Nthawi yomweyo, magulu a hydroxyl sagwirizana bwino ndi mamolekyu a rabara (makamaka omwe si a polar), zomwe zimapangitsa kuti mgwirizanowo ukhale wofooka. Pakawonongeka, silica imatha kuchoka pa rabara, zomwe zimachepetsa kukana kwa kukwawa.
(2) Yothandizidwa ndi Silane Coupling Agent: Zolumikizira (monga Si69) zimagwira ntchito ndi magulu a hydroxyl, kuchepetsa kusonkhana kwa tinthu tating'onoting'ono ndi kuyambitsa magulu ogwirizana ndi rabara (monga magulu a mercapto), kukulitsa mphamvu yolumikizirana pakati pa nkhope. Pa nthawiyi, "kukhazikika kwa mankhwala" kumachitika pakati pa silika ndi rabara. Kusamutsa kupsinjika kumakhala kofanana, ndipo kutsekeka kwa nkhope kumakhala kochepa panthawi yopasuka, zomwe zimapangitsa kuti kukana kutsekeka kukhale kolimba kwambiri.
Pomaliza: Kuchuluka kwa hydroxyl kuyenera kukhala kocheperako (magulu 3-5/nm²), ndipo kuyenera kuphatikizidwa ndi chithandizo cha silane coupling agent kuti chikhale cholimba kwambiri komanso kuti chikhale cholimba kwambiri.
Mtengo wa 5.pH
pH ya silika (nthawi zambiri 6.0-8.0) imakhudza kwambiri kukana kwa kukwawa mwa kukhudza dongosolo la rabara lotchedwa vulcanization system.
(1) Yokhala ndi Asidi Wochuluka (pH < 6.0): Imaletsa ntchito ya ma vulcanization accelerators, kuchedwetsa kuchuluka kwa vulcanization, ndipo ingayambitse vulcanization yosakwanira komanso kuperewera kwa crosslink mu rabara. Rabala yokhala ndi crosslink density yochepa imakhala ndi mphamvu zochepa zamakanika (monga mphamvu yokoka, kuuma). Ikawonongeka, imatha kusokonekera ndi pulasitiki komanso kutayika kwa zinthu, zomwe zimapangitsa kuti isawonongeke.
(2) Alkaline Yochuluka (pH > 8.0): Ikhoza kufulumizitsa kufalikira kwa vulcanization (makamaka kwa ma accelerator a thiazole), zomwe zimayambitsa kufalikira kwa vulcanization koyambirira mwachangu kwambiri komanso kusagwirizana kosagwirizana (kufalikira kwa malo kapena kufalikira kwa vulcanization). Malo olumikizidwa kwambiri amakhala ofooka, malo olumikizidwa pansi amakhala ndi mphamvu zochepa; zonsezi zimachepetsa kukana kwa kukwawa.
Pomaliza: Yopanda asidi pang'ono kapena yosagwirizana (pH 5.0-7.0) ndi yabwino kwambiri kuti igwiritsidwe ntchito mofanana, kuonetsetsa kuti makina a mphira ndikuwongolera kukana kukwawa.
6. Zodetsa
Zodetsa zomwe zili mu silica (monga ma ayoni achitsulo monga Fe³⁺, Ca²⁺, Mg²⁺, kapena mchere wosasinthika) zimatha kuchepetsa kukana kwa kukwawa mwa kuwononga kapangidwe ka rabara kapena kusokoneza kuphulika kwa vulcanization.
(1) Ma Ioni a Zitsulo: Ma Ioni a zitsulo zosinthika monga Fe³⁺ amalimbikitsa ukalamba wa rabara, ndikufulumizitsa kusweka kwa unyolo wa rabara. Izi zimapangitsa kuti zinthu ziwole pakapita nthawi, zomwe zimachepetsa kukana kwa kukwawa. Ca²⁺, Mg²⁺ imatha kuchitapo kanthu ndi zinthu zovulcanizing mu rabara, zomwe zimasokoneza kuphulika kwa vulcanization ndikuchepetsa kuchuluka kwa crosslink.
(2) Mchere Wosungunuka: Kuchuluka kwa mchere wodetsedwa (monga Na₂SO₄) kumawonjezera hygroscopicity ya silica, zomwe zimapangitsa kuti thovu lipangidwe panthawi yokonza rabara. Thovu zimenezi zimapangitsa kuti zinthu zisamayende bwino mkati; panthawi yogwiritsidwa ntchito, kulephera kumayamba pamalo amenewa, zomwe zimachepetsa kukana kwa thovu.
Pomaliza: Kuchuluka kwa zinthu zodetsedwa kuyenera kulamulidwa mosamala (monga, Fe³⁺ < 1000 ppm) kuti muchepetse zotsatira zoyipa pa ntchito ya rabara.
Mwachidule, mphamvu yasilika wosungunukaKukana kwa rabara kumachokera ku mphamvu yogwirizana ya zinthu zosiyanasiyana: Malo enieni a pamwamba ndi kukula kwa tinthu tating'onoting'ono kumatsimikiza mphamvu yofunikira yolimbitsa; kapangidwe kake kamakhudza kukhazikika kwa netiweki ya rabara; magulu a hydroxyl pamwamba ndi pH zimawongolera kukhazikika kwa mgwirizano pakati pa zinthu ndi kufanana kwa vulcanization; pomwe zonyansa zimawononga magwiridwe antchito mwa kuwononga kapangidwe kake. Mu ntchito zenizeni, kuphatikiza kwa zinthu kuyenera kukonzedwa bwino malinga ndi mtundu wa rabara (monga, chogwirira cha tayala, chotseka). Mwachitsanzo, zinthu zogwirira ntchito nthawi zambiri zimasankha silica yokhala ndi malo apadera, kapangidwe kapakati, zonyansa zochepa, komanso kuphatikiza ndi chithandizo cha silane coupling agent kuti chiwonjezere kukana kwa zopweteka.
Nthawi yotumizira: Julayi-22-2025