This invention relates to a process for the in-situ preparation of polymer blends of ethylenically unsaturated monomers which are polymerized with different catalyst systems.
It is known from published Dutch patent application No. 6601466 to use a peroxide in a metathesis-catalyst system. According to the disclosed process, the active catalyst species (a metal carbene) is formed by the combination of tungsten hexachloride, a peroxide in a 1:1 molar ratio, and a metal alkyl activator. According to this disclosure, the introduction of oxygen is essential for the formation of an active metal carbene species (spectator oxygen effect).
German published patent application No. 1954829 discloses the radical polymerization of styrene in the presence of dissolved polycyclopentene. In this publication, reference is made to Dutch patent application No. 6601466 for the preparation of polycyclopentene. According to this process, the polycyclopentene is separately prepared with a metathesis-catalyst system and, after isolation (by means of catalyst decomposition, deashing, drying, etc.), dissolved in styrene, after which the peroxide is introduced.
From published Japanese patent application No. 63128016, a process is known for the preparation of a blend of a ring-opening polymerized body of norbornene derivatives, which is immersed with vinyl aromatic monomer, whereafter said vinyl aromatic monomer is polymerized in aqueous suspension using a radical polymerization initiator. The norbornene derivative, having a polar radical, preferably should have a specific structure, whereas the vinyl aromatic monomer is preferably styrene, methyl styrene, ethyl styrene, and the like, and the radical polymerization initiator is an oil-soluble type.
Polymer blends obtainable by the processes as disclosed in the above-discussed patent publications lack the properties necessary for high-performance polymer applications.
It is therefore an object of the invention to provide an improved and economical manufacturing process for the sequential polymerization of at least two monomers by two different mechanisms. A further object of the invention is to provide improved polymer blends derived from monomer mixtures.