Cov Neeg Sawv Cev Coupling yog dab tsi thiab lawv cov Haujlwm Tseem Ceeb

 

 

Cov Neeg Sawv Cev Coupling yog dab tsi thiab lawv cov Haujlwm Tseem Ceeb

 

Hauv kev lag luam pleev xim, kua mem, thiab cov nplaum, koj puas feem ntau ntsib cov teeb meem no: cov txheej txheem ntawm cov iav substrates tev tawm tom qab rhaub, qhov poob qis ntawm lub zog nplaum ntawm cov khoom tooj liab lossis nyiaj tom qab thermal aging, lossis kev sib kis tsis sib xws thaum cov kua silanes raug ntxiv rau cov hmoov txheej?
Cov teeb meem no, uas zoo li yog cov teeb meem ntawm "kev tsis sib haum xeeb ntawm cov khoom siv," feem ntau yog los ntawm ib qho khoom siv tseem ceeb - tus neeg sawv cev sib txuas. Muaj ntau tus neeg pom tias nws tsuas yog ib yam dab tsi uas "ua rau tej yam lo zoo dua," tab sis nws ua li cas tiag tiag "txuas" ntawm theem molecular? Yuav tsum xaiv nws li cas rau ntau lub tshuab sib txawv, thiab dab tsi yog qhov tsis zoo zais cia hauv nws daim ntawv thov?

 

Yog li ntawd, qhov tseeb yog dab tsitus neeg sawv cev txuasIb tug neeg sawv cev txuas yog ib tug "choj molecular" uas muaj peev xwm ua rau muaj kev cuam tshuam nrog cov pab pawg ua haujlwm ntawm cov khoom siv inorganic (xws li hlau, iav, lossis cov khoom sau) thaum tseem tsim cov tshuaj sib txuas lossis cov molecular entanglements nrog cov organic polymers (xws li resins lossis rubbers). Nws lub luag haujlwm tseem ceeb yog daws qhov teeb meem tseem ceeb ntawm "inorganic-organic interface incompatibility."

 

Kev Piav Qhia Txog: Tus Tsim "Dual-Function" ntawm Cov Neeg Sawv Cev Sib Txuas

Yuav kom nkag siab txog cov neeg sawv cev sib txuas, peb yuav tsum xub paub txog "cov neeg sib tw" uas lawv hais txog - qhov kev tawm tsam ntawm cov ntaub ntawv inorganic thiab cov organic polymers:

Cov ntaub ntawv inorganic (hlau, iav, talc, fiberglass, thiab lwm yam): Polar heev, nrog lub zog saum npoo siab; feem ntau cov nto muaj cov pab pawg hydroxyl (-OH) lossis cov orbitals tsis muaj dab tsi (piv txwv li, d-orbitals hauv cov hlau hloov pauv).

Cov polymers organic (epoxy resins, PU, ​​acrylic resins, PP, thiab lwm yam): Tsis muaj zog polar, nrog cov saw hlau molecular yooj ywm; feem ntau yog cov qauv tsis muaj polar lossis tsis muaj zog polar, ua rau kev sib txuas ruaj khov nrog cov khoom inorganic nyuaj.

Tus qauv tsim ntawm cov khoom siv sib txuas yog tsim los kom "tuav ob qho kawg," uas muaj cov "dual-functional" terminals.

 

Ib Qho Kawg "Anchors" Lub Inorganic Theem: Kev Sib Txuas Tshuaj Lom Zem Nrog Cov Nto Inorganic

Piv txwv li, siv cov neeg sawv cev silane coupling uas feem ntau siv, lawv qhov kawg inorganic feem ntau muaj cov pab pawg alkoxy hydrolysable (-Si-OR, qhov twg R yog methyl, ethyl, thiab lwm yam):

Hydrolysis: Thaum muaj dej los yog dej noo, -Si-OR hydrolyzes los tsim cov pab pawg silanol (-Si-OH).

Kev Ua Kom Ntsws: Cov pab pawg silanol raug dej noo nrog cov pab pawg hydroxyl ntawm qhov chaw ntawm cov khoom siv inorganic (piv txwv li, -Si-OH ntawm iav, -M-OH ntawm cov hlau oxides), tsim cov kev sib txuas covalent muaj zog (-Si-O-Si- lossis -Si-OM-). Qhov no ua tau zoo "ntsia hlau" tus neeg sawv cev txuas rau qhov chaw inorganic.

Cov silanes hlau-chelating coj qhov no mus ntxiv: daws qhov teeb meem ntawm cov pab pawg hydroxyl tsawg ntawm cov nplaim xws li tooj liab, nyiaj, lossis nickel, cov qauv heterocyclic hauv lawv cov molecules (muaj cov atoms xws li nitrogen lossis sulfur) tuaj yeem tsim "kev sib koom tes sib koom tes" nrog cov hlau orbitals uas tsis muaj neeg nyob. Lawv kuj tseem tuaj yeem tsim cov "chelating structures" uas ruaj khov tsib lossis rau tus tswv cuab - cov kev sib txuas no muaj zog dua li cov kev sib txuas covalent, kov yeej qhov teeb meem kev lag luam ntawm kev sib txuas tsis zoo ntawm cov silanes ib txwm muaj rau cov substrates tooj liab.

 

Qhov Kawg Lwm Yam "Sib Koom Ua Ke" rau hauv Theem Organic: Kev Sib Txuas Ruaj Khov nrog Cov Resin

Qhov kawg ntawm cov organic ntawm tus neeg sawv cev txuas nqa cov pab pawg ua haujlwm tsim los cuam tshuam nrog cov resin, tsim rau hom resin tshwj xeeb:

Cov txheej txheem epoxy: Nruab nrog cov pab pawg epoxy, lawv tuaj yeem koom nrog ncaj qha rau hauv kev kho thiab kev sib txuas ntawm cov epoxy resins.

Cov txheej txheem UV: Muaj ob txoj kev sib txuas, lawv tuaj yeem cuam tshuam hauv qab lub teeb UV nrog cov dawb radical lossis cationic systems.

PU systems: Nrog cov amino lossis isocyanate pawg, lawv tuaj yeem cuam tshuam nrog isocyanate (NCO) los tsim cov urea linkages.

Cov txheej txheem thermoplastic (PP/PE): Kev koom ua ke ntawm cov saw hlau alkyl ntev lossis cov pab pawg maleic anhydride, lawv sib txuas nrog cov resin los ntawm kev sib txuas ntawm cov molecular (piv txwv li, cov neeg sawv cev titanate coupling).

 

Tus Neeg Sawv Cev Txuas ≠ Surfactant ≠ Dispersant

Peb hom tshuaj ntxiv no feem ntau tsis meej pem, tab sis qhov sib txawv tseem ceeb yog seb lawv puas tsim cov tshuaj sib txuas:

Surfactant: Txhim kho qhov sib xyaw ua ke ntawm cov dej noo los ntawm cov pab pawg hydrophilic-lipophilic; tsis muaj cov tshuaj sib txuas ua ke, ua rau nws yooj yim tsiv teb tsaws chaw thiab ua tsis tiav.

Dispersant: Tiv thaiv kev sib sau ua ke ntawm cov khoom sau los ntawm kev thawb cov nqi lossis kev cuam tshuam steric; feem ntau vam khom kev sib cuam tshuam ntawm lub cev.

Tus Neeg Sawv Cev Txuas: Tsim cov tshuaj sib txuas uas txuas ob qho tib si inorganic thiab organic, ua haujlwm ua tus choj interfacial "mus tas li". Nws tsis yog tsuas yog faib cov khoom sib xyaw xwb tab sis kuj ua rau lub zog thiab kev ruaj khov ntawm kev sib txuas interfacial.

Tshawb xyuascov nplooj ntawv webrau ntau yam khoom. Yog xav paub ntxiv, thovtiv tauj peb.