Ngokungafani ne-thermoplastics, ama-elastomers asetshenziswa ngokuvamile ngaphezulu kwamazinga okushisa ahlukahlukene futhi ngenhla ngaphezulu kokushisa kwengilazi yawo (TG). Izinzuzo zama-elastomers ngaphezulu kwama-thermoplastics yikhono lazo lokubuyisa cishe ngokuphelele esimweni se-tensile (ukuqina okuphezulu), kanye nobulukhuni obuphansi kanye nezakhiwo eziphansi ze-modulus. Lapho ama-lastomers asetshenziswa ngaphansi kwamazinga okushisa egumbi, akhombisa ukwanda kobulukhuni, ukwanda kwe-modulus, kanye nokwehla kokuqina. Lapho ama-lastomers asetshenziswa ngaphansi kwamazinga okushisa egumbi, kunokuthambekela kobulukhuni ukwanda, i-modulus yokwanda, ukunwebeka ukwehla, ukuncipha okuphansi) kanye nokucindezela kusethwe. Ngokuya ngenkinga nge-elastomer, izehlakalo ezimbili zenzeka ngasikhathi sinye - ukuqina kwengilazi kanye ne-partial crystallization - r, i-ERDM, i-NR kwezinye izibonelo zama-lastomers abonisa i-crystallization.
1. Ukubuka konke ukuhlolwa kokushisa okuphansi
I-Brittleness, ukucindezelwa kwezinguquko zaphakade, ukukhishwa kwemali, ukuqina kanye nokuqina kwe-cry Ukuphumula okucindezelayo kwengcindezi kusemqoka futhi kugxile ekunqumeni amandla okubekwa uphawu kwezinto ezibonakalayo esikhathini esithile ngaphansi kwezimo ezahlukahlukene zezemvelo.
2. Izinga lokushisa eliphakeme
I-ASTM D 2137 ichaza izinga lokushisa elicwengekileyo njengamazinga okushisa aphansi lapho irabha elivuselelwa ngalo ngeke libonise ukuqhekeka noma ukuqhuma ngaphansi kwezimo ezicacisiwe zomthelela. Izinhlobo ezinhlanu zenjoloba zombuso onqunywe kusengaphambili zilungisiwe, zibekwe egumbini noma eliphakathi nendawo, lifakwe emazingeni okushisa okusethiwe ngo-3 ± 0.5min, bese linikeza i-velocity ye-2.0 ± 0.2m / s. Ama-specimens asuswa futhi ahlolwe ngomthelela noma ukuhlolwa kokuqhuma. I-specimen isuswa futhi ihlolwe ngomthelela noma ukuqhekeka, konke ngaphandle komonakalo. Ukuhlolwa kwaphindwa kufinyelela emazingeni okushisa acwengekile - izinga lokushisa eliphansi kakhulu lapho kutholakala khona ukwaphuka kwalo kwakusondele kakhulu ku-1 ° C.
I-3
Inqubo yokuhlola yesethi yokushintshana okushisa okuphansi isondele kakhulu kulokho ngokusetha okujwayelekile kokushintshana, ngaphandle kokuthi izinga lokushisa lilawulwa yindlela ethile yamandla, njenge-icerrogen eyomile, noma izindlela zemishini, kanye nenani lokushisa le-1. Ngemuva kokululama kusuka ku-FIXTRE, i-specimen ibuye ibekwe emazingeni okushisa aphansi asethiwe futhi yabumba ububanzi be-29 mm kanye nobukhulu be-12,5 mm. Isethi yokucindezela okushisa okuphansi iyindlela eqondile yokufaka uphawu kokubekwa uphawu okukhulunywa ngayo. Ukuphumula kwengcindezi kwengcindezi kuyindlela eqondile futhi kuzoxoxwa ngayo ngokuhamba kwesikhathi. Ukuqina okushisa okuphansi kuvame ukunqunywa kusetshenziswa i-Vulcani evuselelwa i-Specimen (29mm x 12.5mm), kepha kuhlolwe kabusha ekulweni okuphansi kokushisa, bese kuthi futhi kumazinga okushisa afanayo. Isethi yokuguqula okunzima kanye nokushisa okuphansi ithinteka ngqo ekupholiseni, kepha futhi ngokuthambekela kwe-polymer ukuze kuncike ekushiseni kwezinga lokushisa, ikakhulukazi ngenxa yokungatholakali kwe-polymer chain izingxenye (ikakhulukazi ngenxa yokungatholakali kwe-polymer chain izingxenye (ikakhulukazi ngenxa yokuphuma kokungatholakali kwe-polymer chain izingxenye (ikakhulukazi ngenxa yokungatholakali kwe-polymer chain.
4. Ukushisa okuphansi kwe-gehman
I-ASTM D 1053 ichaza indlela yokushisa okushisa kaphansi kanjena: uchungechunge lwezinhlamvu ze-e-e-e-e-e-e-e-e-e-e-eastic zinamathiselwe ngokungaguquki olunama-torsional olwaziwayo njalo, futhi elinye ukuphela kocingo linamathiselwe ekhanda lokuthola amandla okuvunyelwa. Ama-specimens agxiliswe ekudluliseleni okushisa okuphakathi nendawo yokushisa engezansi kwejwayelekile, lapho inhloko ye-torsion isontekile ngemali (ngaphansi kwe-180 °) okuncike ku-inversen ngokuguquguquka kwe-specimen nokuqina. Ngemuva kwalokho sebenzisa inani le-goniometer ukuthola inani le-specimen twist, i-angle yokusonta nobulukhuni bezinto zenjoloba. Ukushisa kohlelo kukhuphuke kancane kancane ngalesi sikhathi, futhi icebo le-angle lokusonteka kokushisa liyatholakala. Amazinga okushisa lapho i-modulus ifinyelela ku-T2, T10, kanye ne-T100 kuvame ukuqoshwa njengokulingana nenani le-modulus ekushiseni kwegumbi.
I-5. Ukuvuselelwa okuphansi kokushisa (ukuhlolwa kwe-TR)
The TR test is utilized to evaluate the ability of a specimen in the tensile state when compressive permanent deformation and compressive stress relaxation determined by compressive stress are used to determine low temperature effects. Njengoba embozwe ngaphambili, ama-polymers amaningi afana ne-NR ne-PVC azoshaya amazinga okushisa aphansi, kepha ukwelula angaphinda futhi aze afike ezintweni ezingezekile lapho ebheka izakhiwo ezingezekile. Ukuthola izicelo zokuhlola njengokumiswa kwemali, tr ngaphansi kwengxabano kufanelekile kakhulu futhi kusetshenziswa kaningi. Kulolu vivinyo, i-specimen iphakeme (imvamisa ngamaphesenti angama-50 noma i-100%) futhi iqhwa ezweni eliphakeme. I-specimen ikhishwa, lapho izinga lokushisa liphakanyiswa ngesivinini esinqunyelwe ukukala ukululama kwe-specimen, ubude be-shrinkage bulinganiswa futhi kuqoshwe kabusha. Amazinga okushisa avela kuwo ngo-10%, ama-30%, ama-50%, futhi ama-70% ajwayele ukubonwa njengo-TR10, TR30, TR50, ne-TR70. I-TR10 iphathelene nokushisa kobucwebecwebe; I-TR70 iphathelene nokuguqulwa okungapheli kohlelo lokushintshana okuphansi kokushisa; Futhi umehluko phakathi kwe-TR10 ne-TR70 kusetshenziselwa ukukala i-crystallization of the specimen (ngokwehlukahlukana okukhulu, kukhudlwana kuthambekele kokukhazimula).
6. Ukuphumula okuphansi kwengcindezi okuphumuzayo kwengcindezelo (CSR)
Ukuhlolwa kwe-CSR kungasetshenziswa ukwenza izibikezelo ngokusebenza nokuphila kwezinto zokwakha uphawu. Lapho kunikezwa i-elastomeric compound deformation, amandla ahlanganisiwe ayadalwa, kanye nekhono lezinto ezibonakalayo ukuze ulondoloze leli butho ngaphakathi kwebanga elithile lezemvelo lilinganisa amandla alo okusolisa. Zombili izindlela zomzimba nezamakhemikhali zifaka isandla ekuphumuleni kwengcindezi, ngokususelwa ngesikhathi kanye nokushisa, okuyisici esisodwa kuzobusa, okuholela ekucindezelekeni kwe-chain, okuholela ekuhlolweni kwe-crubber kanye nokuphumula kohlelo lokususa izingcindezi kanye nohlelo lokususa izingcindezi kuvuselelwa. Emazingeni okushisa aphezulu, ukwakheka kwamakhemikhali kunquma isilinganiso sokuphumula, lapho izinqubo zomzimba sezivele zincane futhi ukuphumula kwamakhemikhali akunakuphikiswa, okuholela ekuphendukeni kwe-chain kanye nokuphendula okuxhumene kochungechunge. Ukushisa nge-cycling noma ukwanda okungazelelwe kuzinga lokushisa kungaba nomthelela ekuphumuleni kwengcindezi kuma-elastomers. Ngesikhathi sokuhlolwa kwe-CSR, i-test specimen ibekwe
Ngesikhathi sokuhlolwa kwe-CSR, ukuphumula kwengcindezi kuyanda lapho i-test specimen ifakwa emazingeni okushisa aphakeme. Uma ukuphumula kwengcindezi kwenzeka kusenesikhathi esivivinyweni, inani lokuphumula okwengeziwe okukhuphuka kuqala futhi linenani eliphakeme ngesikhathi somjikelezo wokuqala. Esiqeshini sokuhlola esikhulu esithe xaxa ukukhiqiza amasampula e-gasket (ububanzi obungaphandle kwe-19mm, ububanzi be-15mm), okushisa ngo-25 24H, sonke isikhathi sokuhlola ekuvikelweni kokuhlola, izinga lokushisa lokuhlola, ukuzimisela okuqhubekayo kwamandla. Ukulinganiswa kwamandla kwenziwa ngokuqhubekayo kulo lonke isikhathi sokuhlolwa ekushiseni kokuhlola.
7. Umphumela wokuqukethwe kwe-ethylene
7.1 Okuqukethwe kwe-Ethylene kunomthelela omkhulu kakhulu ekusebenzeni okuphansi kokushisa kwama-ePDM polymers. Ama-polymers ngokuqukethwe kwe-ethylene okusukela ku-48% kuya ku-72% ahlolwe ngaphansi kokwenziwa kwekhwalithi ephezulu. Zonke zihlose ukunciphisa umehluko ekuvulekekeni kwe-money ngokwazisa kwe-ENB kulezi zinhlamvu ezihlukile.
I-ePDM Rubber i-amorphous uma isilinganiso se-ethylene / i-proplene silingana futhi ukusatshalaliswa kwama-monomers amabili ku-polymer chain akuhleliwe. I-EPDM eno-48% no-54% okuqukethwe kwe-ethylene akusho ukuthi ku-christalting kumazinga okushisa egumbi noma ngaphezulu. Lapho okuqukethwe kwe-ethylene kufinyelela ama-65%, ukulandelana kwe-ethylene kuqala ukwanda ngenani nobude futhi kungakha amakristalu, aqashelwe eziqongweni ze-crystallization kuma-DSC azungeze ama-40 ° C. Okukhulu iziqongo ze-DSC, zikhudlwana amakristalu akha.
7.2 Ngaphezu komphumela wokuqukethwe kwe-ethylene kwizakhiwo eziphansi zokushisa okuxoxwe ngazo kamuva, usayizi we-crystallite uthinte ukukhululeka nokucutshungulwa kwamakhompiyutha aqukethe amakristalu. Usayizi we-crystallite, umsebenzi owengeziwe wokushisa nomsebenzi we-shear uyadingeka esigabeni sokuxuba ukuze uhlanganise ngokuphelele i-polymer nezinye izinto. Amandla enjoloba aluhlaza ahlanganisiwe we-EPDM akhuphuka ngokunwetshwa kwe-ethylene. Emakwakheni uphawu lapho kulinganiswa khona umphumela wokuqukethwe kwe-ethylene, ukwanda kokuqukethwe kwe-ethylene kusuka ku-50% kuya ku-68% kuholele ekunyukeni okungenani okune-68% kumandla enjoloba. Ubulukhuni begumbi lokushisa buye bukhuphuka futhi nokwanda kokuqukethwe kwe-ethylene. Usogwini ubulukhuni be-amorphous polymer anama-adhesive angama-63 °, kanti ogwini ubulukhuni be-polymer ngokuqukethwe okuphezulu kakhulu kungu-79 °. Lokhu kungenxa yokwanda kokulandelana kwe-ethylene, ukukhuphuka kwe-crystallization ekunamathisweni, kanye nokwanda okuhambisanayo kwama-polmoplastic polymers.
7.3 Lapho ubunzima bukalwa emazingeni okushisa aphansi, ngokungafani nama-polymers anokuqukethwe okuphezulu kwe-ethylene, kanti ushintsho olungaphansi kokuqukethwe okuphezulu, ukuze ubulukhuni buhlale luphezulu kokuqukethwe kwegumbi, ukuze ama-polmer aqukethe okuqukethwe okuphezulu kwegumbi, ukuze ama-polmers aqukethe okuqukethwe okuphezulu kwegumbi, ukuze ama-polyerers aqukethe ubulukhuni obuphakeme kakhulu.
7.4 Isethi yokushintshana incike kakhulu ekushiseni kokuhlola. Uma kuhlolwe ngo-175 ° C, akukho mehluko kusethi yokucindezela phakathi kwanoma yimaphi ama-polymers (isethi athonywe ukwakheka kwe-compound kanye nokukhethwa kohlelo lokuvuselela). Ngemuva kokuncibilikisa amakristalu e-ethylene, i-polymer ikhombisa ifomu le-amorphoous, futhi ukuze ihlole umphumela wokuqukethwe kwe-ethylene, izivivinyo zenziwa ngo-23 ° C. Ama-polymers anokuqukethwe okuphezulu kwe-ethylene enobuhlakani obukhulu obuphezulu (ngaphezu kokuphindwe kabili), kanye nomphumela wokuqukethwe kwe-ethylene kukhulu kakhulu uma kuhlolwe ku-20 ° C no-40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. -40 ° C. Ama-polymers anokuqukethwe okungaphezu kwama-60% ethylene defformation ephakeme kakhulu (> 80%); Ku-AT -40 ° C, ama-polymers agcwele aphelele anokuguquguquka okuphakade okuphansi (17%).
7.5 Umphumela wokuqukethwe kwe-ethylene kumazinga okushisa aphansi okuqinisa izivivinyo ze-gehman. Ngokunikwa okushisa, okuphezulu ekhoneni, kwehlisa ukwanda kokuqina (noma ukwanda kwe-modulus). Emazingeni okushisa aphansi, ukuqina kwe-modulus kukhuphuka kakhulu ngokunwetshwa kwe-ethylene. Kuma-amorphous polymers, i-T2 ingu-47 ° C, kuyilapho okuqukethwe okuphezulu kakhulu kwe-ethylene kune-T2 ye--16 ° C.
7.6tr Ukulinganisa Ukuvuselelwa Kwe-Shrimpage of Specimens ngemuva kokunwebeka kwezezimali, okuqukethwe kwe-ethylene kunomthelela omkhulu kwindlela yokuhlola, okubuye kufane nokuhlolwa kweGehman.
Lokhu kuyafana nokuhlolwa kweGehman. I-Shrinkage (%) yama-polymers ahlukahlukene ayahlukahluka njengomsebenzi wokushisa, nama-amorphous polymers athola ukululama okuphezulu kakhulu emazingeni okushisa aphansi; Kodwa-ke, njengoba kubikezelwe, ukutakula kuwohloka njengoba okuqukethwe kwe-ethylene kukhuphuka emazingeni okushisa anikezwe.
ukululama kuyawohloka. Inani le-TR10 liyahlukahluka kusuka ku -53 ° C kuma-Amorphous Polymers kuya ku-28 ° C yama-polymers anokuqukethwe okuphezulu kwe-ethylene.
7.7 Umjikelezo wokuphumula wokuphumula wengcindezelo (CSR)
Umjikelezo. Cindezela amakhompiyutha, ubavumele baphumule ngo-25 ° C. bese bewabeka emjikelezweni wamazinga okushisa asukela ku-20 ° C kuya ku-110 ° C. Lapho kucindezelwa okokuqala, ngemuva kwesikhathi sokulingana, i-crystalline polymer e inokulahleka okuphezulu kwengcindezi kune-polymer ye-amorphoous, kanti lapho yehliswa ku-amorphous force of the polymers ezimbili inciphisa, ngenkathi i-amorphous pormer inengcindezi ephezulu (ephakeme f / f0). Ukushisa i-Compound kuya ku-110 ° C kubuyiselwe amandla ayo okubopha uphawu, futhi lapho kubuyiselwa emuva ku-20 ° Umjikelezo olandelayo waveza iziphetho ezifanayo. Kuyacaca ukuthi ama-amorphous polymers aphakeme kakhulu ngezinhlelo zokusebenza zokubopha lapho kusebenza khona ukusebenza okushisa okuphansi.
8. Umphumela wokuqukethwe kwe-diolef
Ukuhlinzeka ngephuzu elingalawulwa elidingekayo eVulcanins, ama-diolefins angewona ahlanganiswe afana ne-ENB, i-HX ne-DCPD yengezwa kuma-pollene e-ethylene propylene polymers. I-applix eyodwa ephindwe kabili ku-matrix ye-polymer, kuyilapho isebenza ngesibili njenge-polymerizer chain futhi ihlinzeka nge-Vulcanization Point ye-Sulfur Yellow Vulcanization. Umphumela we-ENB wahlolwa eWindvield (Rain) Amaphrofayili we-Bar. Ama-polymers aqukethe ama-2%, ama-6% no-8% enB aqhathaniswa.Ingezwe se-ENB yaba nomthelela omkhulu kwizici ze-vulcanization kanye nobuningi be-crosslink. Modululus inyukile ngenkathi ukugcwala kwehle kakhulu. Ubulukhuni bukhuphuke futhi isethi yokushintshana yathuthukiswa ngesikhathi sokushisa lokushisa. Njengoba okuqukethwe kwe-ENB kukhuphuka, isikhathi sokushaya i-chriring siba mfushane.
I-Enb iyinto ebonakalayo, futhi uma ingezwe ku-polymer backbone, kuphazamisa ukukleliswa kwengxenye ye-polymer ye-polymer, ukuze ama-polymers anokuqukethwe okufanayo kwe-enthylene. Emazingeni okushisa ekamelo, okuqukethwe okuphezulu kwe-ENB kuthuthukisa kancane isethi yokuxhuma ngenxa yobuningi be-crosslink ethuthukisiwe. Kodwa-ke, emazingeni okushisa aphansi, isethi yokucindezela kwama-polymers anokuqukethwe okuphezulu kwe-enb ingcono kakhulu kunaleyo yama-polymers anokuqukethwe okungu-2% encb. Umphumela wokuqukethwe kwe-Enb ekushiseni kwe-brittleness, ukukhishwa kokushisa, nokuhlolwa kukaGehman akukhombisanga noma yimuphi umehluko obalulekile ekushiseni kwe-brittleness phakathi kwama-polymers ngokuvamile, nangokuhlolwa kwe-GR, i-polymer ngayinye ikhombise ukuthuthuka kwezindawo zokushisa eziphansi ngokuqukethwe okuphansi kwe-enb.
I-9. Umphumela we-Money Viscosity Ezakhiweni Zokushisa Eziphansi
Kuyaziwa ukuthi i-Money Viscosity (Mass Molecular) inomthelela omkhulu ekuziphatheni okuhle kwama-elastomers. Ekwenzweni nasekuhlolweni kokubumba ekukhishweni nezinhlelo zokusebenza zokubumba, kubalulekile ukukhetha i-Compound enenani elifanelekile le-Money Viscosity. Kusetshenziswa ukwakhiwa okufanayo okwakusetshenziselwa ukuphenya umphumela we-monomer yesithathu, amazinga okushisa aphansi ukuhlola i-money viscosities, ama-polymers aqhathaniswa nama-monerey ama-polymers akhuphuke njengoba i-money vismers esetshenzisiwe lapho ama-polymers asetshenziswe khona. Amandla asheshayo, amamodulomu, kanye namandla enjoloba aluhlaza akhuphuke ngokuqagela okwandayo kwe-money. Umphumela we-Money Viscosity ezimweni zokushisa eziphansi ze-EPDM ayibalulekile. Kodwa-ke, ukucindezelwa kwezinguquko unomphela emazingeni okushisa asekamelweni, - 20 ° C no-40 ° Creases nge-Molecular Mass ekhulayo. Kodwa-ke, ukucindezela kusethwe emazingeni okushisa asekamelweni, - 20 ° C no-40 ° C C AKUFUNI ukuthi kukhuphuke kakhulu ngobuningi be-molecular, kanti ukuguquguquka okusendaweni okuphakeme kwamazinga okushisa (175 ° C) kukhombise izinguquko ezithile ze-viscosives ephakeme ye-EPDM.
10. ISIPHETHO
Okuqukethwe kwe-ethylene kanye ne-diolef kunomthelela obalulekile ekusebenzeni kwama-elastomers e-EPDM ezisetshenzisweni eziphansi zokushisa, nama-polymer anokuqukethwe okuphezulu kwe-ethylene esebenza kahle ngenxa yokuphazamiseka kwengxenye ye-polymer ye-polymer. Ukuqukethwe okuphansi kwe-ethylene appmer kufanele kusetshenziswe lapho ukusebenza okuphansi kokushisa kuwumkhawulo.
