Txhawm rau tiv thaiv kev tsiv teb tsaws chaw thiab nthuav dav ntawm cov yas, txoj hauv kev los txwv kev tsiv teb tsaws chaw ntawm cov yas suav nrog kev kho PVC saum npoo av, kho kom zoo nkauj PVC, sib xyaw nrog cov yas yas, ntxiv nanoparticles, ntxiv montmorillonite, thiab so hauv cov kuab tshuaj organic. , Ua covalent daim ntawv cog lus nrog PVC, kev hloov kho yas yas, thiab lwm yam.
(1) PVC kho saum npoo
①Surface cross-linking
Kev hla kev sib txuas ntawm PVC tuaj yeem txo qhov khoob ntawm PVC ntu, yog li ua rau muaj kev cuam tshuam rau kev tsiv teb tsaws chaw thiab nthuav tawm ntawm cov yas yas. Qhov sib txuas sib txuas ntawm PVC tuaj yeem tsim ua ob seem sib txuas sib txuas ua ke zoo li cov qauv, tsim ua" rub" thiab" qhwv" cuam tshuam rau cov yas yas yas thiab cuam tshuam kev tsiv teb tsaws chaw thiab nthuav tawm ntawm cov yas yas. Txoj kev ntawm kev hloov pauv kev sib txuas yog feem ntau ua rau PVC nrog azide, sodium sulfide, thiab lwm yam, ua kev kho ntshav, lossis ua lub teeb ci ultraviolet.
UrSurface txheej
Txhawm rau txo qhov kev tsiv teb tsaws chaw thiab rho tawm cov yas yas hauv cov polymer, ib txoj hauv kev txheej txheej txheej ntawm cov polymer nrog txheej txheej ntawm cov tshuaj tsis txav chaw tuaj yeem siv tau. Dissolve PVC hloov pauv nrog hloov Cl atoms hauv cov kuab tshuaj organic, siv nws rau saum cov khoom lag luam PVC muag muag, thiab kho cov txheej los ntawm cua sov lossis lub teeb ci ci. Siv txoj hauv kev no los ua ib txheej 30μm nyias tuaj yeem tiv thaiv kev txav chaw ntawm cov yas yas.
(2) Kev hloov kho PVC kev sib tsoo
Kev hloov pauv ntawm PVC tuaj yeem txuas PVC cov saw hlau txuas nrog lwm txoj haujlwm sib txuas los ntawm cov khoom sib txuas sib txuas, txwv lossis txo qis kev txav ntawm PVC ntu, thiab txo qis kev tsiv teb tsaws thiab nthuav tawm ntawm cov yas. β-Cyclodextrin (β-CD) yog cyclic compound tsim los ntawm kev sib txuas 7 glucopyranose molecules. Nws muaj cov qauv kab noj hniav uas raug txiav kom luv. Ob qhov kawg yog hydrophilic vim muaj cov pab pawg hydroxyl. Qhov kab noj hniav yog vim C -H daim ntawv cog lus Muaj hydrophobicity, thiab cov qauv kab noj hniav hydrophobic tuaj yeem nqus tau thiab nqus cov yas yas yas, yog li ua rau cuam tshuam kev tsiv teb tsaws ntawm cov yas. Nyob rau tib lub sijhawm, txoj kab nkhaus uas tsim los ntawm β-CD tom qab siv tau tuaj yeem tiv thaiv kev tsiv ntawm cov yas yas. Cov thev naus laus zis ntawm kev ntxiv β-CD yog qhov yooj yim, tab sis nws muaj qhov tsis sib xws nrog PVC thiab kev tsis sib xws tsis sib xws.
(3) Sib tov nrog cov yas yas polymer
Thaum qee cov ntaub ntawv polymer tau sib xyaw nrog PVC, lawv muaj kev sib raug zoo nrog PVC, uas tuaj yeem txo qhov iav hloov pauv kub ntawm PVC, txhim kho kev hloov pauv, thiab ua lub luag haujlwm zoo ib yam rau cov yas yas me me, uas tuaj yeem suav hais tias yog Molecular plasticizer siab. Nyob rau tib lub sijhawm, hom yas yas no muaj qhov hnyav hnyav hnyav, feem ntau ntau dua 1000. Piv nrog cov yas yas me me, nws muaj kev txav chaw zoo thiab tiv taus kub tsawg, thiab tseem hu ua yas yas ruaj khov. Polymer yas yas feem ntau kim thiab yuav txo qhov pob tshab ntawm cov khoom PVC tom qab muab ntxiv. Nyob rau tib lub sijhawm, cov yas yas polymer muaj teeb meem ntawm kev ua yas tsis zoo. Lawv tuaj yeem txhim kho kev ua kom zoo dua qub thaum ua ke nrog cov yas yas me me.
Muaj peb hom tseem ceeb ntawm cov yas yas polymer, uas yog polyester, ethylene copolymer thiab elastomer. Polyester yas yas yog tsim los ntawm polycondensation ntawm saturated dibasic acid thiab dibasic cawv, nrog lub cev hnyav ntawm 800-8000. Tom qab cov yas yas polyester tau sib xyaw nrog cov yas yas me me, nws tuaj yeem nyiam thiab txhim kho cov yas yas me me thiab tiv thaiv nws kom tsis txhob kis mus rau saum PVC. Ethylene copolymers feem ntau suav nrog ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-carbon monoxide-vinyl acetate copolymer (Elvaloy) thiab lwm yam. Elvaloy yog cov khoom lag luam ntawm DuPont, nrog cov yas zoo heev. Roj hmab Nitrile (NBR) yog cov yas yas elastomer. Tom qab NBR sib xyaw nrog DOP, nws tuaj yeem txo qhov kev tsiv teb tsaws chaw ntawm DOP.
(4) Ntxiv nanoparticles
Nanoparticles muaj thaj tsam tshwj xeeb loj, ntau qhov atoms saum npoo, tsis muaj cov atoms uas nyob ib puag ncig ib puag ncig atoms, muaj ntau qhov kev sib khi ua ke, tsis txaus, thiab yooj yim rau nqus tau lwm yam tshuaj, xws li polar me me molecule yas yas. Nyob rau tib lub sijhawm, nanoparticles tsis yooj yim rau tsiv mus nyob hauv PVC, uas tuaj yeem cuam tshuam kev txav ntawm PVC molecular saw thiab yas yas yas. Yog li, ntxiv nanoparticles rau PVC tuaj yeem txo qhov kev tsiv teb tsaws chaw ntawm cov yas.
Cov thev naus laus zis ntawm kev ntxiv cov nanoparticles yog qhov yooj yim thiab tus nqi qis, tab sis nws yuav txo qis kev ua haujlwm ntawm cov yas yas, thiab yuav txo qis cov dej tsis kam, pob tshab thiab cov yam ntxwv ntawm cov khoom PVC.
(5) Ntxiv montmorillonite
Montmorillonite yog cov dej uas muaj aluminosilicate av nplaum nrog cov qauv lamella tshwj xeeb nrog tuab li ntawm 1 nm. Tom qab montmorillonite hla kev hloov kho cov organic, qhov sib cuam tshuam sib nrug nce. Sib tov montmorillonite nrog PVC tuaj yeem ua rau montmorillonite lamella tawg hauv PVC hauv daim ntawv ntawm ib daim, thiab cov qauv lamella tuaj yeem nce ntxiv. Plasticizer molecules tsim ib&"labyrinth pathway &"; los cuam tshuam kev tsiv teb tsaws chaw ntawm cov yas, yog li txwv tsis pub cov tsiv teb tsaws chaw ntawm cov yas.
Txawm li cas los xij, qhov sib ntxiv ntawm montmorillonite yuav ua rau kom nyuaj ntawm PVC ua thiab tsis cuam tshuam rau thermal stability ntawm PVC.
(6) Organic solvent immersion
Kev tsiv teb tsaws chaw thiab nthuav tawm ntawm cov yas yas hauv PVC tau ua los ntawm qhov khoob ntawm PVC ntu. PVC muaj cov yas yas tuaj yeem suav tias yog rubbery, thiab PVC ntu ntu yog muag muag; thaum PVC tsis muaj cov yas yas, nws tuaj yeem yog Raws li nws nyob hauv lub xeev iav, PVC txheej txheej txheej txheej txheej txheej yog ntom thiab tsis muaj qhov khoob. Thaum cov khoom lag luam PVC tau raus rau hauv cov kuab tshuaj organic rau lub sijhawm luv, cov yas rau ntawm cov khoom siv PVC txav mus rau cov tshuaj hnyav ua ntej, ua ob daim iav&"crystalline thin layers &"; tsis muaj cov yas yas, thiab cov yas yas hauv PVC Thaum cov kuab tshuaj txav mus los, nws ntsib teeb meem ntawm&"crystalline thin layer &";
(7) Tsim covalent daim ntawv cog lus nrog PVC
Tsis muaj tshuaj lom neeg sib txuas ntawm PVC cov saw hlau thiab cov yas yas, thiab kev sib cuam tshuam tsis muaj zog. Thaum lub sijhawm ua thiab siv, cov yas yas nquag txav mus los thiab nthuav tawm. Yog tias cov yas yas yas txuas rau hauv PVC cov saw hlau sib txuas los tsim covalent daim ntawv cog lus, cov yas yas tau dhau los ua ib feem ntawm PVC, uas tuaj yeem tiv thaiv kev tsiv teb tsaws chaw thiab nthuav tawm ntawm cov yas yas. Feem ntau, cov yas yas me me tau hloov pauv hloov rau PVC. Cl ntawm cov saw molecular.
(8) Kev hloov kho yas yas
Txhawm rau txo lossis tshem tawm qhov exudation ntawm cov yas yas me me, cov yas yas me me tuaj yeem hloov kho kom ua rau muaj qhov sib npaug lossis hnyav hnyav ntawm cov yas yas me me. Feem ntau siv txoj hauv kev suav nrog kev qhia ntawm Cl atoms rau hauv cov yas yas, nyob hauv qhov chaw siv tshuaj tua kab mob, thiab muab cov pawg macromolecular rau ntawm cov yas yas me me. Siv cov tshuaj dawb hloov pauv cov tshuaj tiv thaiv kab mob, Cl tau nkag mus rau hauv cov kua qaub methyl ester kom tau txais chloromethoxy fatty acid methyl ester, uas txhim kho kev sib raug zoo thiab kev tsiv mus nyob ntawm cov yas thiab PVC, thiab muaj qee yam nplaim hluav taws.