Nyrim process

Scheme 7.3 Preparation of block copolymers of lactams the Nyrim process.

This process, commonly used with thermosets, is sometimes used for specific thermoplastics such as monomers or pre-polymers of PMMA or polyamide (Nyrim). For the latter, a mix is made just before casting with ... 

Monomeric and oligomeric forms of caprolactam modified with a compatible elastomer (such as butadiene) and usually glass-fibre-reinforced, can be conveniently processed using reaction injection moulding equipment to produce block copolymers of PA 6, (e.g. Dutch State Mines Nyrim ). Applications include panels for the underside of snowmobiles. 

Essentially, the process shows dose similarities to polyurethane and polyurea RIM. Therefore, the machinery developed for these latter polymers and well known in the industrial practice can be readily adapted to NyRIM. The specific requirements of the RIM process applied to CL anionic polymerization have been summarized by Macosko in terms of unit operations. The initiators typically used are sodium c-caprolactamate or magnesium bromide c-caprolactamate. 

The Nyrim technology was the first successfiil process to produce block copolymers, namely, poly(E-caprolactam)-blodk-polyether [53]. The OH end-groups of the prepolymer are transformed to the growth centers through an alcoholysis of bis(acyllactams) (Scheme 7.3). 

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