It is well known that application of flow fields can enhance nucleation rate by orders of magnitude in polymers. The mechanism is still under debate, a recent concept point that specific work hypothesis determines the onset and the extent of the phenomena.  Here we use the rheo- Raman microscope to carry the critical test on this hypothesis.  The instrument provides the ability to simultaneous measure the growth of shear modulii (via rheology), along with helicity of chains (via Raman) and growth of spherulites (via optical microscopy) further, in a parallel plate geometry the latter two can be measured as a function of radial position. This capability provides us with the ability to modify the applied specific work by five orders of magnitude. We report the scaling of the crystallization half-time as a function of both specific work and shear rate.

Flow induced crystallization in isotactic polypropylene via simultaneous measurements of modulus, helicity and morphology

255th National Meeting (2018)

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