A polymer composition in solid form contains hydrogenated units of a polymer composed of diene monomer units and nitrile group containing monomer units. The hydrogenated polymer has an .alpha./.beta. peak ratio >1, measured by .sup.1H-NMR. The a peak is measured between 2.05 and 2.2 ppm. The .beta. peak is measured between 1.8 and 2.05 ppm. The polymer composition has a gel content of less than 15 wt. % and a molecular weight distribution (of its soluble part) of less than 10. The polymer compositions may be used to form articles, such as automotive parts, which are less sensitive to oxidation degradation.
The invention relates to a composite material and a process for manufacturing the composite material by applying at least a single organic barrier layer to a substrate to reduce the oxygen permeability of the substrate. Depending on the intended application, the composite material may also include an outer cover layer over the barrier layer to improve moisture resistance. The preferred materials are triazines, particularly melamine, that are vapour-deposited onto the substrate to form a thin, durable transparent barrier layer.
The invention relates to a process for the hydrogenation of a polymer composed of diene monomer units and nitrile group containing monomer units in which crosslinks formed as a result of the hydrogenation are broken by adding, before, during or after the hydrogenation, a compound that satisfies the formula R.sub.1--N (H) --X (I) or (R.sub.1) (R.sub.2)C.dbd.N--Y (II), where R.sub.1 is a hydrogen atom, an alkyl or cycloalkyl group with 1-30 carbon atoms, or an aromatic group with 6-30 carbon atoms and R.sub.2 is an alkyl or cycloalkyl group with 1-30 carbon atoms, or an aromatic group with 6-30 carbon atoms, X is chosen from the group comprising --R.sub.3, --OR.sub.4, --SR.sub.4, --NR.sub.5R.sub.6, where R.sub.3, R.sub.4 and R.sub.5 are a hydrogen atom, an alkyl or cycloalkyl group with 1-30 carbon atoms or an aromatic group with 6-30 carbon atoms and R.sub.6 is an alkyl or cycloalkyl group with 1-30 carbon atoms or an aromatic group with 6-30 carbon atoms Y is chosen from the group comprising --R.sub.7, --OR.sub.8, --SR.sub.8, --NR.sub.9R.sub.10 and --N.dbd.CR.sub.11R.sub.12, where R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11 and R.sub.12 are a hydrogen atom, an alkyl or cycloalkyl group with 1-30 carbon atoms or an aromatic group with 6-30 carbon atoms, and where it is possible for R.sub.3-R.sub.12 to also contain one or more heteroatoms from the groups 13, 14, 15, 16 or 17 of the Periodic System of the Elements. The invention also relates to a polymer composition containing the hydrogenated polymer in solid form.