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Differenza Tra EPDM e EPR

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(:title Differenza Tra EPDM e EPR:)
August 23, 2016, at 12:21 PM by 79.58.39.104 -
Changed lines 8-26 from:
L'aggiunta del terzo componenente nell'EPDM e' dovuto solo ad un motivo tecnico di vulcanizzazione. La




To make a rubber material rubbery, we essentially have to “glue” the polymer chains together. We do this
through a process called vulcanization or curing. This is where the subtle difference between EPR and
EPDM is found. Because of the chemistry of the polymer chain, EPR can only be vulcanized with a
peroxide-based cure system. On EPDM, the additional diene monomer provides a specialized cure site that
allows the polymer to be vulcanized with peroxide- or sulfur-based chemistries. Because of this added
flexibility, most EP compounds in the seal industry today use EPDM terpolymer instead of EPR
copolymer
. In other industries (hose, roofing products, etc.) EPRs may still be the material of choice.
From a functional standpoint, there are very few performance differences between EPR and EPDM. Both
swell dramatically in petroleum products, and both are excellent in water, steam, and polar solvents like
MEK and acetone. There are some notable performance differences in extremely demanding applications:
EPRs or very tightly cured EPDMs are suited for the nuclear industry (E0740-75 is recommend), and for
applications involving concentrated acetic acid, some EPDM compounds (like E0692-75) show superior
performance to most EPRs. In other applications, the performance difference is difficult (if not impossible)
to identify
to:
L'aggiunta del terzo componenente nell'EPDM e' dovuto solo ad un motivo tecnico di produzione: la vulcanizzazione. La vulcanizzazione e' il sistema per unire insieme le molecole, l'EPR ha solo un modo per vulcanizzare, l'EPDM ha piu' modi per vulcanizzare e quindi e' piu' facile da produrre.

Entrambi sono ottimi con acqua, vapore, sovventi polari (acetone). Entrambi si gonfiano drammaticamente con i prodotti petroliferi.
Le uniche applicazioni dove si notano leggere differenze sono quelle nucleari, dove e' preferito EPR, o l'acido acetico dove e' peferito l'EPDM. In tutti gli altri casi non si notano differenze
.
August 23, 2016, at 12:15 PM by 79.58.39.104 -
Changed lines 3-15 from:
EPR e' un etilene-propilene-copolimero


In the range of ethylene-propylene (EP) rubber there are two slightly different branches: EPR (EP
copolymer) and EPDM (EP terpolymer.) The differences are subtle, and a basic knowledge of polymers
and rubber compounding is necessary to grasp the differences.
First of all, polymers (derived from the Greek for “many units”) are long chemical chains that can be
thought of as behaving like long pieces of cooked spaghetti. Each chain is made of one or more monomers
(Greek “single unit”) linked together end-to-end. A copolymer (Greek “two units”) is composed of two
monomers, while a terpolymer (Greek “three units”) is composed of three monomers. EPR (aka EPM, EP
copolymer) contains only ethylene and propylene monomers. EPDM (aka EPT, EP terpolymer) is
composed of ethylene, propylene, and a third monomer called a diene (three different dienes are in
common use today, but discussing their differences gets extremely dry and technical.)
to:

EPR e' un etilene-propilene-copolimero, cioe' contiene solo due catenete di polimeri: l'etilene e il propilene.

EPDM  e' un etilene-propilene-terpolimero, cioe' contiene  tre catene di polimeri: l'etilene, il propilene e il diene.

L'aggiunta del terzo componenente nell'EPDM e' dovuto solo ad un motivo tecnico di vulcanizzazione. La



August 23, 2016, at 12:11 PM by 79.58.39.104 -
Added lines 1-29:
Esistono due gomme molto utilizzate nel settore delle guarnizioni: EPR e EPDM. Qual e' la differenza?
In breve '''nessuna''', nel dettaglio  analizziamo le differenze qui di seguito:
EPR e' un etilene-propilene-copolimero


In the range of ethylene-propylene (EP) rubber there are two slightly different branches: EPR (EP
copolymer) and EPDM (EP terpolymer.) The differences are subtle, and a basic knowledge of polymers
and rubber compounding is necessary to grasp the differences.
First of all, polymers (derived from the Greek for “many units”) are long chemical chains that can be
thought of as behaving like long pieces of cooked spaghetti. Each chain is made of one or more monomers
(Greek “single unit”) linked together end-to-end. A copolymer (Greek “two units”) is composed of two
monomers, while a terpolymer (Greek “three units”) is composed of three monomers. EPR (aka EPM, EP
copolymer) contains only ethylene and propylene monomers. EPDM (aka EPT, EP terpolymer) is
composed of ethylene, propylene, and a third monomer called a diene (three different dienes are in
common use today, but discussing their differences gets extremely dry and technical.)
To make a rubber material rubbery, we essentially have to “glue” the polymer chains together. We do this
through a process called vulcanization or curing. This is where the subtle difference between EPR and
EPDM is found. Because of the chemistry of the polymer chain, EPR can only be vulcanized with a
peroxide-based cure system. On EPDM, the additional diene monomer provides a specialized cure site that
allows the polymer to be vulcanized with peroxide- or sulfur-based chemistries. Because of this added
flexibility, most EP compounds in the seal industry today use EPDM terpolymer instead of EPR
copolymer. In other industries (hose, roofing products, etc.) EPRs may still be the material of choice.
From a functional standpoint, there are very few performance differences between EPR and EPDM. Both
swell dramatically in petroleum products, and both are excellent in water, steam, and polar solvents like
MEK and acetone. There are some notable performance differences in extremely demanding applications:
EPRs or very tightly cured EPDMs are suited for the nuclear industry (E0740-75 is recommend), and for
applications involving concentrated acetic acid, some EPDM compounds (like E0692-75) show superior
performance to most EPRs. In other applications, the performance difference is difficult (if not impossible)
to identify

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