Kusiyana ne thermoplastics, elastomers anowanzo shandiswa pamusoro peyakasiyana tembiricha uye zvakanyanya pamusoro pegirazi yavo yekuchinja tembiricha (Tg). Zvakanakira zve elastomers pamusoro pe thermoplastics kugona kwavo kudzoreredza zvakazara kubva kune tensile mamiriro (yakakwira elasticity), pamwe neyakajairwa elasticity, kuderera kuoma uye kuderera modulus zvimiro. Kana elastomers inoshandiswa pasi pekushisa kwekamuri, inoratidza kuwedzera kwekuoma, kuwedzera kwe modulus, uye kuderera kwekusagadzikana. Kana elastomers inoshandiswa pazasi tembiricha yekamuri, pane katsika kekuti kuomarara kuwedzere, modulus kuwedzera, elasticity kuderera (yakaderera tensile) uye compression yakaiswa kuwedzera. Zvichienderana nedambudziko ne elastomer, zviitiko zviviri zvinogona kuitika panguva imwe chete - kuomeswa kwegirazi uye chidimbu crystallization - CR, EPDM, NR mimwe mienzaniso yeelastomers inoratidza crystallization.
1. Overview yepasi tembiricha bvunzo
Brittleness, kudzvanya zvachose deformation, kudzoreredza, kuomesa uye cryogenic kuomeswa kwakashandiswa kwemakore mazhinji kuitira kuratidza zvinhu zvepolymer pane tembiricha yakaderera. Compressive stress relaxation ichiri chitsva uye inotarisa pakuona simba rekuisa chisimbiso chechinhu kwenguva yakati rebei pasi pezvakasiyana mamiriro ezvakatipoteredza.
2. Brittleness Temperature
ASTM D 2137 inotsanangura tembiricha yebrittleness seye tembiricha yakaderera apo rabha ine vulcanized isingaratidze kutyoka kana kuputika pasi pemamiriro akatarwa. Mienzaniso mishanu yerabha yechimiro chakafanotemerwa inogadzirirwa, inoiswa mukamuri kana mvura yepakati, inoiswa pasi petembiricha yakatarwa ye3± 0.5min, yobva yapihwa kumhanyisa velocity ye2.0±0.2m/s. Zviyero zvinobviswa uye zvinoiswa pasi pekukanganiswa kana kuputika bvunzo. Muenzaniso wacho unobviswa uye unoyedzerwa kuona kana kutyoka, zvese pasina kukuvara. Muedzo wacho wakadzokororwa kusvika ku brittleness tembiricha - tembiricha yakaderera pasina kutyoka kwakawanikwa yaive padyo ne1 ° C.
3. Low Temperature Compression Set uye Low Temperature Hardening
Maitiro ekuyedza ekudzikira-tembiricha yekumanikidza seti iri padhuze neiyo yekumisikidzwa kwakajairwa seti, kunze kwekunge tembiricha inodzorwa neimwe nzira yesimba, senge yakaoma ice ice, liquid nitrogen, kana mechanika nzira, uye kukosha kuri mukati ± 1 ° C yetembiricha yakafanorongwa. Mushure mekupora kubva mugadziriso, iyo sampuli inoiswawo pane preset yakaderera tembiricha uye yakaumbwa kusvika dhayamita ye29 mm uye ukobvu hwe12.5 mm. Yakaderera-tembiricha yekumanikidza seti inzira isina kunanga yekuisa chisimbiso maapplication ekomboni iri mubvunzo. Compressive stress relaxation ndiyo nzira yakananga uye ichakurukurwa gare gare. Kuomesa tembiricha kuomeswa kunowanzo kutsanangurwa uchishandisa vulcanized compression set specimen (29mm x 12.5mm), asi yakaedzwazve pane yakaderera tembiricha control, iyo yakafanana neyekumanikidza set, uyezve patembiricha yakafanana setembiricha yavo. Kuomesa uye kudzika-tembiricha compression set inokanganiswa zvakananga nekutonhodza, asiwo nekatsika kepolymer kupenya, nechiyero checrystallization zvinoenderana netembiricha, semuenzaniso, CR inopenya nekukurumidza kutenderedza -10 ° C, uye yobva yadzikira pakudzika kwakadzika, zvakanyanya nekuda kwekusafamba kwepolymer cheni zvikamu (iyo mamorekuru mashetani akasununguka).
4. Gehman Low Temperature Kuomesa
ASTM D 1053 inotsanangura nzira yekudzika-tembiricha yekuomesa sezvinotevera: mutsara we elastic polymer specimens zvakanamirwa zvakanamirwa kune waya ine inozivikanwa torsional constant, uye imwe mugumo wewaya inonamirwa kune torsion musoro unokwanisa kubvumira waya kumonyoroka. Mienzaniso inonyudzwa mumhepo yekupisa kupisa pane imwe tembiricha iri pasi peyakajairika, panguva iyo musoro wehutu unomonyoroka ne 180 °, uye ipapo zvienzaniso zvinomonyoroka nehuwandu (pasi pe180 °) zvinoenderana nekusiyana kweiyo specimen kuchinjika uye kuoma. Wobva washandisa huwandu hwegoniometer kuona huwandu hwemuenzaniso wakamonyoroka, kona yekumonyoroka uye kuoma kwezvinhu zverabha. Kupisa kwegadziriro yacho kunowedzera zvishoma nezvishoma panguva ino, uye chirongwa chekona ye twist kurwisana nekushisa inowanikwa. Iwo tembiricha iyo modulus inosvika T2, T10, uye T100 inowanzorekodhwa seyakaenzana neiyo modulus kukosha pakamuri tembiricha.
5. Kudzikira kweTemperature Retraction (TR Muedzo)
Iyo TR bvunzo inoshandiswa kuongorora kugona kwemuenzaniso mune inotenha mamiriro apo inomanikidza zvachose deformation uye compressive kusagadzikana kuzorora kunotemerwa nekumanikidza kushushikana kunoshandiswa kuona yakadzika tembiricha mhedzisiro. Sezvakafukidzwa kare, akawanda mapolymers akaita seNR nePVC anopenya patembiricha yakaderera, asi kutambanudza kunogona zvakare kupenya, zvichitungamira kune zvimwe zvinhu kana uchitarisa kune yakaderera tembiricha zvivakwa. Kumashandisirwo ekuongorora akadai sekumiswa kwekupedza simba, TR pasi pekunetsekana kwakakodzera uye kunowanzoshandiswa. Mumuedzo uyu, mufananidzo wacho wakareba (kazhinji ne50% kana 100%) uye wakaoma nechando munzvimbo yakareba. Iyo muenzaniso inoburitswa, panguva iyo tembiricha inosimudzwa pamwero wakatemerwa kuyera kudzoreredza kwemuenzaniso, kureba kwekuderera kunoyerwa uye elongation yakanyorwa. Matembiricha ayo sampuli inodzikira ne10%, 30%, 50%, uye 70% inowanzozivikanwa seTR10, TR30, TR50, uye TR70. TR10 inoenderana neiyo brittleness tembiricha; TR70 inoenderana nekugadziriswa kwechigarire kwemuenzaniso mukudzika-kupisa kwekumanikidza; uye mutsauko uripo pakati peTR10 neTR70 unoshandiswa kuyera crystallization yemuenzaniso (yakanyanya mutsauko, iyo yakakura tsika yekupenya).
6 . Low Temperature Compressive Stress Relaxation (CSR)
Iyo CSR bvunzo inogona kushandiswa kufanotaura nezve kuita uye hupenyu hwekuisa chisimbiso zvinhu. Kana iyo elastomeric komputa ikapihwa kushanduka kunogara kuripo, simba rakasanganiswa rinogadzirwa, uye kugona kwechinhu kuchengetedza iri simba mukati meimwe nharaunda nharaunda inoyera kugona kwayo kuvhara. Zvose zvemuviri uye zvemakemikari maitiro anobatsira mukuzorodza kushushikana, zvichienderana nenguva uye tembiricha, chimwe chinhu chinozotonga, kuzorora kwemuviri kunoonekwa pakudziya kwakadzika, pakarepo mushure mekushushikana kwakapihwa, izvo zvinotungamira mukugadziriswazve kweketani uye shanduko munzvimbo yerubha-yekuzadza uye yekuzadza-kuzadza, uye kuzorora kweiyo kushushikana yekubvisa sisitimu inodzoserwa. Pakupisa kwepamusoro, chimiro chemakemikari chinotarisa mwero wekuzorora, kana maitiro emuviri atove madiki uye kuzorora kwekemikari kusingadzoreki, zvichitungamira mukutsemuka kweketani uye kuyambuka-kubatanidza maitiro. Tembiricha kuchovha bhasikoro kana kuwedzera kamwe kamwe tembiricha kunogona kuve nemhedzisiro yekuzorora kwekushushikana mu elastomers. Munguva yekuedzwa kweCSR, chiyero chekuyedza chinoiswa
Munguva yekuyedzwa kweCSR, kuzorora kwekushushikana kunowedzera kana bvunzo yemuenzaniso inoiswa kune tembiricha yakakwira. Kana kuzorora kwekushushikana kunoitika pakutanga kwekuyedzwa, huwandu hwekuwedzera kuzorora hunowedzera kutanga uye hune huwandu hwepamusoro panguva yekutanga kutenderera. Muchidimbu chakakura chekuyedza kugadzira sampuli dzegasket (19mm yekunze dhayamita, dhayamita yemukati ye15mm), ine elastic fixture inomanikidzwa kune sampuli kune yavo tembiricha yekamuri ukobvu hwe25%, uye pa25 ℃ mukamuri yekuyedza yezvakatipoteredza, tembiricha iri pa25 ℃ kuchengetedza 24h, uyezve kudzika kusvika -4h, ichiteverwa ne24h, inoteverwa ne25h, inoteverwa -20 ~ 110 ℃ kutenderera kwe24h, nguva yese yekuyedza patembiricha yekuyedza, tembiricha yekuyedza, kuenderera kwesimba kutsunga. Kuyera kwesimba kunoitwa nguva dzose munguva yekuedza panguva yekushisa kwekuedza.
7. Mhedzisiro yeEthylene Content
7.1 Ethylene yemukati ine yakanyanya kukanganisa pane yakaderera tembiricha kuita kweEPDM polymers. Mapolymer ane Ethylene zvemukati kubva pa48% kusvika 72% akaongororwa pasi pemhando yepamusoro yekuvharisa maumbirwo. Zvese zvinovavarira kudzikisa kusiyanisa kwemoonney viscosity nekuunza ENB mune aya akasiyana mapolymer.
EPDM rabha iamorphous kana ethylene/propylene ratio yakaenzana uye kugoverwa kwemamonomeri maviri mucheni yepolymer zvisina tsarukano. EPDM ine 48% uye 54% ethylene yemukati haina crystallize pane kana pamusoro pekamuri tembiricha. Kana iyo ethylene yemukati yasvika 65%, iyo ethylene sequences inotanga kuwedzera munhamba uye kureba uye inogona kugadzira makristasi, ayo anocherechedzwa mu crystallization peaks paDSC curves yakatenderedza 40 ° C. Iyo yakakura iyo DSC yepamusoro, iyo yakakura makristasi anoumba.
7.2 Pamusoro pekuita kweiyo ethylene yemukati pane yakaderera tembiricha zvinhu zvinokurukurwa gare gare, crystallite saizi inokanganisa kusununguka kwekusanganisa uye kugadzirwa kwemakemikari ane makristasi. Iyo yakakura saizi yekristallite, iyo yakanyanya kupisa uye kugera basa rinodiwa padanho rekusanganisa kuti rinyatso sanganisa iyo polymer nezvimwe zvikamu. Simba rerabha rakasviba reEPDM rinowedzera nekuwedzera ethylene content. Mukugadzira chisimbiso apo mhedzisiro ye ethylene yemukati yakayerwa, kuwedzera kweiyo ethylene yemukati kubva pa50% kusvika 68% yakakonzera kanenge mana kuwedzera kwesimba rerabha. Iko kuoma kwekamuri-tembiricha kunowedzerawo nekuwedzera ethylene yemukati. The Shore Kuoma kweamorphous polymer adhesive i 63°, nepo Shore A kuoma kwepolymer ine ethylene yemhando yepamusoro i79°. Izvi zvinokonzerwa nekuwedzera kwe ethylene sequence, kuwedzera kwekristalllization mune yakanamatira, uye kuwedzera kunoenderana ne thermoplastic polymers.
7.3 Kana kuomarara kuchiyerwa patembiricha yakaderera, mukusiyana nemapolymer ane ethylene yakakwira, mapolima amorphous anoratidza kushanduka kushoma mukuoma, nepo kushanduka kwekuoma kweiyo ethylene yemukati kusingaratidzi mutsara pateni uye kuoma kunoramba kwakakwira pakupisa kwekamuri, kuitira kuti mapolymers ane ethylene yepamusoro yemukati arambe aine yakanyanya kuoma tembiricha.
7.4 Compression set inonyanya kuenderana netembiricha yekuyedza. Kana yakaedzwa pa 175 ° C, hapana mutsauko mukumanikidzwa kwakaiswa pakati pemapolymers (seti inokonzerwa nekugadzirwa kwekomboni uye kusarudzwa kwevulcanization system). Mushure mekunyunguduka kwemakristasi ethylene, iyo polymer inoratidza chimiro cheamorphous, uye kuitira kuti uongorore mhedzisiro yezvinyorwa zveethylene, miedzo yakaitwa pa23 ° C. Mapolymers ane ethylene yakakwira yemukati zviri pachena ane yakakwirira zvachose deformation (yakapetwa kaviri zvakanyanya), uye mhedzisiro ye ethylene yemukati inotokura kana yakaedzwa pa -20 ° C uye -40 ° C. Mapolymers ane anopfuura 60% ethylene zvemukati ane yakakwirira zvachose deformation (> 80%); pa -40 ° C, chete amorphous mapolima akazara ane yakaderera zvachose deformation (17%).
7.5 Mhedzisiro yeEthylene Content pane Yakaderera Tembiricha Kuomarara kubva kuGehman Miedzo. Zvichipa tembiricha, iyo yakakwira kona, yakaderera kuwedzera kwekuoma (kana kuwedzera mu modulus). Pakudziya kwakadzika, iyo kuomarara modulus inowedzera zvakanyanya nekuwedzera ethylene yemukati. Kune amorphous polymers, iyo T2 i -47 ° C, nepo ethylene yemukati polymer ine T2 ye -16 ° C chete.
7.6TR Kuyera shrinkage kudzoreredzwa kwezvienzaniso mushure mekuwedzera kutonhora, iyo ethylene yemukati ine yakakosha mhedzisiro payedzo nzira, iyo yakafanana zvakare neiyo Gehman bvunzo.
Izvi zvakafanana nebvunzo yeGehman. Iyo shrinkage (%) yemapolymer akasiyana-siyana inosiyana sekushanda kwekushisa, neamorphous polymers ine yakanyanya shrinkage kudzoreredza pakudziya kwakaderera; zvisinei, sezvakafanotaurwa, kupora kunowedzera sezvo ethylene yemukati inowedzera pane imwe tembiricha.
kupora kunokanganisa. Kukosha kweTR10 kunosiyana kubva -53°C kune amorphous polymers kusvika -28°C yemapolymer ane high ethylene content.
7.7 Compressive stress relaxation (CSR) kutenderera
Cycle. Dzvinyirira mishonga, bvumira kuti vazorore pa 25 ° C kwe 24 h, uye wovaisa mumhepo yekushisa kubva -20 ° C kusvika 110 ° C intermittently for 24 h. Kana yakamanikidzwa kekutanga, mushure menguva yekuenzanisa, iyo crystalline polymer E ine kurasikirwa kwakanyanya kwekushushikana kupfuura iyo amorphous polymer, uye kana yadzikiswa kusvika -20 ° C simba rekuvharisa remapolymer maviri rinodzikira, nepo amorphous polymer A ine kuchengetedzeka kwakanyanya kwekushushikana (yakakwirira F/F0). Kupisa komboni kusvika 110 ° C kwakadzoreredza simba rayo rekuisa chisimbiso, uye payakadzoserwa pasi kusvika -20 ° C, iyo yakasara yekuisa chisimbiso simba recrystalline polymer yaive isingasviki 20% yekukosha kwayo, iyo inowanzoonekwa yakaderera kune akawanda maapplication, neamorphous polymer inochengeta zvinopfuura 50% yesimba rekuisa chisimbiso, uye iine amorphous repolymer repamusoro zvakare. Chikamu chinotevera chakapa mhedziso dzakafanana. Zviripachena kuti amorphous mapolymers ari pamusoro pekuisa chisimbiso maapplication uko yakakwirira uye yakaderera tembiricha kuita kunodiwa.
8. Mhedzisiro yeDiolefin Content
Kupa iyo isina unsaturated poindi inodiwa vulcanization, isina-conjugated diolefins senge ENB, HX uye DCPD inowedzerwa kune ethylene propylene polymers. Imwe yakapetwa kaviri chisungo inobata mupolymer matrix, nepo yechipiri ichiita semubatsiri kune polymerized molecular cheni uye inopa vulcanization poindi yesarufa yero vulcanization. Mhedzisiro yeENB yakaongororwa muwindshield (mvura) bar profiles. Mapolymers ane 2%, 6% uye 8% ENB akafananidzwa.Kuwedzerwa kweENB kwakave nemigumisiro inokosha pamhando dzevulcanization uye crosslink density. Modulus yakawedzera nepo kureba kwakadzikira zvakanyanya. Kuomarara kwakawedzera uye kumisikidzwa kwakagadziridzwa panguva yekukwira kwekushisa. Sezvo zvinyorwa zveENB zvichiwedzera, nguva yekuchaja inova pfupi.
ENB ndeye amorphous material, uye kana yakawedzerwa kumusana wepolymer, inokanganisa crystallization ye ethylene chikamu chepolymer, kuitira kuti mapolymers ane zvakafanana ethylene zvinyorwa zvinogona kuwanikwa, uye zvinyorwa zvepamusoro zveENB zvinovandudza kuderera-kupisa zvinhu. Pamukamuri tembiricha, iyo yepamusoro ENB yemukati inovandudza zvishoma iyo compression yakaiswa nekuda kweiyo yakagadziridzwa crosslink density. Nekudaro, pakudziya kwakadzika, iyo yekumisikidza seti yemapolymer ane yakakwira ENB yemukati iri nani zvakanyanya pane iyo yemapolymer ane 2% ENB yemukati. Mhedzisiro yezvemukati meENB pane brittleness tembiricha, kudzoreredza tembiricha, uye bvunzo yaGehman haina kuratidza musiyano wakakosha mukupisa kwe brittleness pakati pemapolymers zvakajairika, uye yeGehman's bvunzo uye TR bvunzo, imwe neimwe polymer yakaratidza kuvandudzwa mune yakaderera-tembiricha zvivakwa nekuwedzera ENB zvemukati.
9. Mhedzisiro yemoney Viscosity pane Yakadzika Temperature Properties
Zvinonyatsozivikanwa kuti mooney viscosity (molecular mass) ine mhedzisiro yakakosha pakugadzirisa maitiro e elastomers. Mu extrusion uye molding applications Mu extrusion uye molding applications, zvakakosha kusarudza komboni ine yakakodzera Mooney viscosity value. Kushandisa kuumbwa kwakafanana kwakashandiswa kuongorora mashandiro emutatu monoma, ENB, pane yakaderera-tembiricha zvinhu kuongorora Mooney viscosity, mapolima ane Mooney viscosities ye30, 60, uye 80 akaenzaniswa, uye iyo Mooney viscosity yemakomponi yakawedzera sezvo Mooney viscosity yemapolymers anoshandiswa yakawedzera. Kusimba kwesimba, modulus, uye mbishi rabha simba rakawedzera nekuwedzera Mooney viscosity. Mhedzisiro yeMooney viscosity pane yakaderera tembiricha zvinhu zveEPDM hazvina kukosha. Nekudaro, iyo compression yekusingaperi deformation pane tembiricha yekamuri, -20 ° C uye -40 ° C inowedzera nekuwedzera molecular mass. Zvisinei, kusungirirwa kwakaiswa panzvimbo yekupisa, -20 ° C uye -40 ° C haina kuchinja zvakanyanya nekuwedzera kwema molecular mass, asi kusungirirwa kwakaiswa pakushisa kwakakwirira (175 ° C) kwakaratidza dzimwe shanduko kune yakakwirira mooney viscosities ye EPDM adhesives.
10. Mhedziso
Iyo ethylene uye diolefin yemukati ine mhedzisiro yakakura pakuita kweEPDM elastomers mune yakaderera tembiricha application, ine mapolymers ane low ethylene content anoita zvakanaka uye mapolymer ane yakakwira diolefin content achinatsiridza nekuda kwekuvhiringidza crystallization ye ethylene chikamu chepolymer. Yakaderera ethylene yemukati mapolymers anofanirwa kushandiswa kana yakaderera tembiricha kuita kuri muganhu.
