Tus nqi POE nce ntxiv dua?

Raws li ib qho ntawm cov ntaub ntawv toughening feem ntau siv, qhov dynamic no yeej ua rau cov tuam txhab hloov kho mob taub hau. Lub zog thiab toughness yog ob qho tseem ceeb qhia txog kev ua tau zoo ntawm cov khoom siv, yog li kev hloov kho yas toughening tau yog ib qho tseem ceeb ntawm kev hloov kho yas, thiab niaj hnub no los ntawm Lub Zog thiab toughness yog ob qho tseem ceeb qhia txog kev ua tau zoo ntawm cov khoom siv, yog li kev hloov kho yas toughening tau yog ib qho tseem ceeb ntawm kev hloov kho yas, thiab niaj hnub no los ntawm kev ntxiv cov neeg sawv cev toughening tseem yog txoj hauv kev ncaj qha thiab zoo tshaj plaws ntawm kev toughening cov khoom siv.

Yog li ntxiv rau kev siv elastomer toughening, muaj lwm txoj kev xaiv dab tsi? Hnub no kuv coj koj mus rau kev npaj, kev hloov kho toughening dab tsi yog cov tswv yim ua tau.

Cov neeg sawv cev toughening feem ntau siv tau muab faib ua ob pawg: cov neeg sawv cev toughening nquag thiab cov neeg sawv cev toughening tsis nquag. yog cov uas lawv cov saw molecular muaj cov pab pawg nquag uas tuaj yeem cuam tshuam nrog cov matrix resin, uas tuaj yeem tsim cov qauv network thiab nce ib feem ntawm Cov neeg tawv tsis-reactive yog ib chav kawm ntawm cov neeg tawv uas sib xws zoo nrog cov resin puag, tab sis tsis koom nrog Cov neeg tawv tsis-reactive yog ib chav kawm ntawm cov neeg tawv uas sib xws zoo nrog cov resin puag, tab sis tsis koom nrog hauv kev tshuaj lom neeg.

Cov ntaub ntawv elastomeric toughening

Yuav luag txhua yam khoom siv uas yoog tau siv tau ua cov khoom siv tawv rau cov khoom siv tawg yooj yim, qhov tseem ceeb yog qhov sib xws ntawm cov khoom sib xyaw ua ke, tsuas yog muaj lub kaw lus tawv zoo sib xws kom ua tiav lub hom phiaj tawv uas xav tau, thiab lwm yam nws tsis zoo. Cov khoom siv tawv elastomeric feem ntau siv tau muab faib ua pawg los ntawm lawv qhov kub hloov iav siab lossis qis.

(1) Cov tshuaj resin uas tiv taus kev cuam tshuam siab
Xws li chlorinated polyethylene (CPE), methyl methacrylate-butadiene-styrene copolymer (MBS), acrylate copolymer (ACR), styrene-butadiene block copolymer (SBS), hydrogenated SBS (SEBS), POE, EVA, thiab lwm yam.
(2) Cov roj hmab uas tiv taus kev cuam tshuam siab
Xws li ethylene propylene roj hmab (EPR), EPDM, NBR, NR, SBR, BR, CR, thiab lwm yam.
Ntxiv mus, yog tias TPU siv los ua tus neeg sawv cev rau PA66, lub zog cuam tshuam ntawm PA66/TPU composite tau zoo dua qub, thiab cov khoom tensile ntawm cov khoom sib xyaw tsuas yog txo qis me ntsis xwb. Cov khoom siv kho tshuab ncav cuag qhov zoo tshaj plaws thaum ntxiv TPU yog 5%. Qhov crystallinity txo qis 50%, qhia tias lub kaw lus muaj qhov cuam tshuam pom tseeb rau PA66.

Kev faib tawm los ntawm cov qauv sab hauv ntawm elastomer.

(1) Chav kawm elastomer uas tau teem tseg ua ntej
Lawv yog cov polymers uas muaj cov qauv core-shell, nrog rau lub core elastomer mos mos thiab lub polymer nrog lub plhaub kub hloov iav siab. Xws li MBS, ACS, MABS, thiab lwm yam.
(2) Chav kawm elastomer uas tsis tau teem tseg ua ntej
Nws yog ib qho polymer net, thiab nws qhov kev hloov pauv cuam tshuam yog hloov kho los ntawm cov txheej txheem ua haujlwm ntawm cov kuab tshuaj, xws li CPE, EVA, thiab lwm yam.
(3) Chav kawm elastomer hloov pauv

Cov qauv yog nyob nruab nrab ntawm cov elastomer uas tau teem tseg thiab cov uas tsis tau teem tseg, xws li ABS, thiab lwm yam.

Cov ntaub ntawv tawv tawv

Cov ntaub ntawv inorganic rigid toughening (RIF), feem ntau yog cov khoom siv inorganic ultrafine thiab cov khoom siv tshwj xeeb.

Cov khoom siv inorganic ultra-fine yog hais txog qhov loj ntawm cov khoom me me ntawm 0.1-5μm, qhov hloov pauv ntawm cov khoom siv no nrog rau kev nce ntxiv ntawm cov khoom siv ntxiv, qhov sib xyaw ua ke ntawm lub zog tensile thiab lub zog cuam tshuam txo qis, tsis hloov pauv lossis nce me ntsis, thaum lwm yam khoom txuas ntxiv nce.

Cov khoom siv tshwj xeeb suav nrog cov super fibers (CF), koob/sphere fillers, alkaline earth metal salts thiab cov minerals tsis tshua muaj, thiab lwm yam.

Cov superfibers xws li carbon fibers, boron fibers, quartz fibers, organic fibers, carbon nanotubes thiab ntau yam whiskers. Kev tawg ntawm superfibers hauv polymers yuav tsum tau ua los ntawm cov txheej txheem tshwj xeeb thiab tsom mus rau.

Cov khoom siv zoo li koob xws li wollastonite zoo li koob, uas muaj qee yam kev ua kom tawv.

Feem ntau, nws raug kho nrog silane coupling agent lossis compound coupling agent rau 10-15 feeb ntawm 50-80 ℃, thiab qhov ntxiv ntau npaum li cas raug pom zoo 10-15%. Wollastonite yam tsis muaj kev kho mob tsis muaj cov nyhuv toughening.
Cov khoom siv puv kheej kheej suav nrog cov iav microspheres, iav hollow microspheres, wollastonite hlaws dai, cov hlaws dai yas, cov hlaws dai ceramic, thiab lwm yam.

Cov ntsev hlau alkaline feem ntau suav nrog barium sulfate, qhov ntim puv ntau yam, lub zog cuam tshuam ntawm cov khoom sau muaj ntau qib kev txhim kho, ntawm qhov ntxiv ntawm kwv yees li 60%, lub zog cuam tshuam ncav cuag qhov siab tshaj plaws.
Cov zaub mov tsis tshua muaj av feem ntau yog cov oxides tsis tshua muaj av, alkyl tsis tshua muaj av sib xyaw thiab cov ntsev tsis tshua muaj av, xws li rubidium oxide thiab cerium fluoride. Lub tshuab ua kom tawv ntawm cov zaub mov tsis tshua muaj av feem ntau cuam tshuam nrog lawv cov nucleation, piv txwv li cov av tsis tshua muaj av yog siv los ua cov neeg sawv cev nucleating los txhim kho cov qauv crystalline ntawm lub kaw lus toughening thiab ua tiav lub hom phiaj toughening. Feem ntau siv rau hauv kev ua kom tawv ntawm cov polymers crystalline, xws li PP, PA, POM, thiab lwm yam.

(2) Cov khoom siv organic rigid toughened (ROF)
Xws liPMMA, PP, PS, MMA/S thiab SAN, thiab lwm yam. Nrog rau ob txoj haujlwm ntawm kev ua kom tawv thiab txhawb zog, qhov cuam tshuam ntawm kev ua kom tawv thiab txhawb zog yog parabolic.

Txoj cai ntawm kev ua kom tawv
Thaum cov khoom siv polymer raug kev cuam tshuam thaum cov khoom puas tsuaj (tawg), qhov loj ntawm nws qhov tawv nyob ntawm qhov loj ntawm lub zog cuam tshuam uas cov khoom siv nqus thiab nws lub peev xwm los tiv taus qhov tawg nthuav dav. Yog li cov ntaub ntawv txhawb nqa thiab lub matrix ua lub luag haujlwm li cas hauv kev tawv hauv polymers?

1. Elastomer toughening mechanism

Elastomer nqus tau lub zog ncaj qha, thaum cov qauv raug cuam tshuam yuav tsim cov kab nrib pleb me me, thaum cov roj hmab me me hla ob sab ntawm qhov tawg, qhov tawg kom tsim tau yuav tsum ncab cov roj hmab, cov txheej txheem roj hmab deformation kom nqus tau ntau lub zog, yog li ua rau lub zog cuam tshuam ntawm cov yas nce ntxiv.

2. Txoj kev xav txog qhov ua tau zoo

Cov roj hmab toughened yas muaj zog heev feem ntau yog los ntawm cov matrix resin yield deformation tshwm sim ntau heev, qhov laj thawj uas cov matrix resin yield deformation yog vim tias cov coefficient ntawm thermal expansion thiab Poisson's ratio ntawm roj hmab ntau dua li cov yas, thaum lub sijhawm txias ntawm cov txheej txheem molding, thermal contraction thiab deformation ntawm cov txheej txheem transverse contraction ntawm cov matrix ib puag ncig hydrostatic tension stress, yog li ntawd cov matrix resin dawb ntim nce, txo nws cov iav hloov pauv kub, yooj yim los tsim cov yas deformation thiab txhim kho toughness. Nws yooj yim los tsim cov yas deformation thiab txhim kho toughness. Ntawm qhov tod tes, nws yog tshwm sim los ntawm cov roj hmab cov khoom me me ntawm kev ntxhov siab.

3. Kev tshawb fawb txog lub hauv paus ntawm kev tawg

Cov roj hmab ua haujlwm ua cov chaw sib sau ua ke ntawm kev ntxhov siab, tsim ntau qhov tawg me me es tsis yog ob peb qhov loj, thiab nws siv zog ntau dua los nthuav ntau qhov tawg me me dua li nthuav ob peb qhov loj. Tib lub sijhawm, cov teb ntxhov siab ntawm ntau qhov tawg me me cuam tshuam rau ib leeg, ua rau cov kev ntxhov siab tseem ceeb rau kev tsim cov tawg tsis muaj zog, uas, ua rau qeeb qeeb ntawm kev tsim cov tawg thiab ua rau cov tawg xaus.

4. Txoj kev xav txog ntau yam nyiaj

Vim muaj cov roj hmab ntau heev nyob rau hauv cov yas uas tawv, ntau cov tshuaj ua kom muaj kev ntxhov siab ua rau muaj ntau cov qauv nyiaj, uas tuaj yeem ua rau lub zog ploj mus ntau. Cov roj hmab kuj yog cov kab txiav nyiaj, thiab cov khoom me me tsis tuaj yeem xaus cov kab nyiaj.

5. Txoj kev xav ntawm cov hlua khi nyiaj

Qhov no yog ib lub tswv yim tseem ceeb uas feem ntau lees txais hauv kev lag luam. Muaj ntau qhov kev sim tau qhia tias cov txheej txheem polymer deformation muaj ob txoj hauv kev: ib qho yog cov txheej txheem shear deformation thiab lwm qhov yog cov txheej txheem nyiaj rippling. Cov txheej txheem shear suav nrog ob qho tib si diffuse shear yield deformation thiab kev tsim cov shear bands hauv zos. Shear deformation tsuas yog kev hloov pauv hauv cov duab ntawm cov khoom, lub zog sib koom ua ke ntawm cov molecules thiab qhov ceev ntawm cov khoom yeej tsis hloov pauv. Cov txheej txheem nyiaj striation, ntawm qhov tod tes, ua rau qhov ceev ntawm cov khoom kom txo qis. Ntawm ib sab tes, muaj qhov hauv lub cev nyiaj, qhia tias cov nyiaj grainization tau ua rau muaj kev puas tsuaj rau cov khoom, uas yog qhov ua ntej ntawm kev puas tsuaj sub-microscopic fracture; ntawm qhov tod tes, nyiaj grain siv ntau lub zog hauv cov txheej txheem tsim thiab kev loj hlob, uas txwv tsis pub nthuav dav ntawm cov kab nrib pleb thiab txhim kho qhov tawv ntawm cov khoom, uas yog ib qho ntawm cov txheej txheem kho tshuab ntawm polymer toughening. Yog li ntawd, kev nkag siab zoo txog cov xwm txheej ntawm cov nyiaj yog lub hauv paus ntawm kev nkag siab txog cov txheej txheem deformation thiab tawg ntawm cov ntaub ntawv polymer, thiab yog ib qho ntawm cov yuam sij los ua kom tiav cov qauv tsim ntawm cov yas hloov kho sib xyaw, tshwj xeeb tshaj yog cov yas tawv.

6. Cavitation txoj kev xav

Cavitation theory yog hais txog qhov tshwm sim ntawm cavitation sab hauv cov roj hmab me me lossis ntawm txheej interface ntawm cov roj hmab me me thiab cov substrate nyob rau hauv qhov kev ua ntawm peb-seem kev ntxhov siab hauv cov txheej txheem ntawm qhov kub qis lossis kev hloov pauv ceev ceev. Lub tswv yim hais tias: cov yas hloov kho roj hmab nyob rau hauv qhov kev ua ntawm cov rog sab nraud, cov roj hmab me me disperse theem vim muaj kev ntxhov siab concentration, ua rau qhov sib txuas ntawm cov roj hmab thiab matrix thiab nws tus kheej los tsim cavitation, thaum cov roj hmab me me raug cavitated, qhov kev ntxhov siab hydrostatic tension nyob ib puag ncig roj hmab raug tso tawm, lub xeev kev ntxhov siab ntawm cov leeg matrix nyias nyias ntawm cov qhov, los ntawm peb-seem mus rau ib-seem, thiab lub dav hlau strain mus rau hauv lub dav hlau stress, thiab lub xeev kev ntxhov siab tshiab no yog qhov zoo rau kev tsim cov shear band. Yog li ntawd, cavitation nws tus kheej tsis tuaj yeem tsim kev hloov pauv brittle-tough ntawm cov khoom siv; nws tsuas yog ua rau muaj kev hloov pauv hauv lub xeev kev ntxhov siab ntawm cov khoom siv, uas ua rau shear yielding, tiv thaiv kev nthuav dav ntxiv, thiab txhim kho cov khoom siv toughness.