Copper has long been known to have biocidic properties that can be used to make germ free materials by being added to polymer matrices. Through in-situ synthesis of the nanoparticles in melted polypropylene (PP), a different polymorphism appeared that had unique properties to those of the common alpha phase of PP. This phase, known as the beta phase, is up to 500% more elastic and 300% tougher than the alpha phase. The nucleating ability of the copper nanoparticles to make this beta phase gives a new added versatility to the material to fit a new set of required mechanical properties for different material needs. This extends the range of applications for the material and increases the marketability of biocidic materials using copper nanoparticles. The point of this study is to develop control over the development of the beta phase in order to make the material as stiff or ductile as required. The control was developed via a series of tests that were characterized using XRD as a qualitative measuring tool to see what conditions result in more or less beta phase. The wt% of copper nanoparticles as well as the quenching rate and final processing temperature were varied to see the effect each parameter would have on the development of the beta phase. The results showed that with lower quenching rates and a higher copper wt% more beta phase appears relative to the alpha phase but, developing precise control over the percentage of beta phase present has a lot of fine tuning left to be completed.