Low molecular weight model study of peroxide cross-linking of EPDM

Topics: Alkene, Chemistry, Organic reaction Pages: 45 (5823 words) Published: February 26, 2014
Downloaded from UvA-DARE, the institutional repository of the University of Amsterdam (UvA) http://dare.uva.nl/document/122453

File ID

6: Low-molecular-weight model study of peroxide cross-linking of EPDM rubber using gas chromatography–mass spectrometry : addition and combination
Final published version (publisher's pdf)

Characterisation of polymeric network structures
R.A.H. Peters
Faculty of Science


It is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), other than for strictly personal, individual use.

UvA-DARE is a service provided by the library of the University of Amsterdam (http://dare.uva.nl)



Low-molecular-weight model study of
peroxide cross-linking of EPDM rubber
using gas chromatography and mass
Addition and combination

The dicumyl-peroxide-initiated addition and combination reactions of mixtures of alkanes (n-octane, n-decane) and alkenes (5,6-dihydrodicyclopentadiene (DCPDH), 5-ethylidene-2-norbornane (ENBH) and 5-vinylidene-2-norbornane (VNBH)) were studied to mimic the peroxide cross-linking reactions of terpolymerised ethylene, propylene and a diene monomer (EPDM). The reaction products of the mixtures were separated by both gas chromatography (GC) and comprehensive two-dimensional gas chromatography (GC×GC). The separated compounds were identified from their mass spectra and their GC and GC×GC elution pattern. Quantification of the various alkyl/alkyl, alkyl/allyl and allyl/allyl combination products show that allylic-radicals comprise approximately 60% of the substrate radicals formed. The total concentrations of the products formed by combination are found to be independent of the concentration and the type of alkene. In addition, the total concentration of the formed addition products depends strongly on the type of the alkene used, viz. VNBH > ENBH ≈ DCPDH, which is a consequence of differences in steric hindrance of the unsaturation. The peroxide curing efficiency, defined as the number of moles of cross-linked products formed per mol of peroxide, is 173% using 9% (w/w) VNBH. This indicates that the addition reaction is recurrent. In addition, the present results provide more-detailed structural information. The described approach to use low-molecular-weight model compounds has proven to be a very powerful tool to study the cross-linking of EPDM.

R. Peters, M. van Duin, D. Tonoli, G. Kwakkenbos, Y. Mengerink, R. van Benthem, C.G. de Koster, P. Schoenmakers, Sj. van der Wal, Journal of Chromatography A, 1201 (2008) 151160.


6.1. Introduction
EPDM rubber is an elastomer, which is terpolymerised from ethylene, propylene and a diene monomer. Due to its excellent resistance to heat, ozone, oxygen and water, it can be used for a wide range of outdoor and demanding applications [1]. It dominates the market for non-tyre rubber applications (e.g. window or door sealing). EPM (a copolymer of ethylene and propylene) can be cross-linked with peroxides, but the introduction of a diene ter-monomer strongly improves the cross-linking efficiency. The two dienes commonly used in commercial EPDM are dicyclopentadiene (DCPD) and 5-ethylidene-2-norbornene (ENB) (Fig. 6.1) [2]. Recently a new advanced catalyst technology was developed, which enables the incorporation of up to 3% (w/w) of 5-vinylidene-2-norbornene (VNB) (Fig. 6.1) into EPDM, without the occurrence of polymer-reactor fouling or excessive polymer branching [3]. The concentration and the type of the diene significantly influence the peroxide curing efficiency. It has been shown that the curing efficiency is governed by steric effects [4]. VNB is the most...

References: London, 1988.
OH, October 16-18, 2007, ISSN:1547-1977.
M. van Duin, H.G. Dikland, Rubber Chem. Technol. 76 (2003) 132.
Technol. 71 (1998) 105.
V.M. Litvinov, M. van Duin, Kautsch. Gummi Kunstst. 55 (2002) 460462.
V. Livinov, Macromolecules 39 (2006) 8727-8741.
J.B. Phillips, J. Beens, J. Chromatogr. A 856 (1999) 331.
Blomberg, J. of High Resol Chrom. 23 (2000), 507-510.
Chromatogr. A 1086 (2005) 12-20.
J.K. Kochi (Ed), Free radicals, vol. 1, John Wiley & Sons, New York,
Eigenmann, J. Phys. Chem. Ref. Data. 3 (1974) 937.
Continue Reading

Please join StudyMode to read the full document

You May Also Find These Documents Helpful

  • Molecular weight Essay
  • Advantages of Low Molecular Weight Heparin Essay
  • Essay about cross linking effects on polymers
  • Molecular Weight of a Condesable Vapor Essay
  • low birth weight & preterm Essay
  • study model Essay
  • A Low Involvement Hierarchy Model Essay
  • The effect of molecular weight on the diffusion rate Essay

Become a StudyMode Member

Sign Up - It's Free
Électronique | Heroglyph v2.6.24. | Batería QUMOX LP-E12 para Canon EOS M, M50, M2, M100, M10, 100D