My graduate research was in the title topic. It actually a very interesting topic to study as it is a very unusual phenomenon. In a nut shell, crystallizable polymers (such as PE, PP,...) can crystallize extremely quickly at high temperatures when flowing, temperatures that are so high that the crystallization is non-existent in the absence of the the flow. This happens in both the melt as well as in solutions.
After school, I left the topic alone. My work had been in ultra-dilute solutions, (0.01 wt%) so the practical applications of that specific approach were negligible. However, I just ran across a review paper that just came out back in September (open access until the end of November) and was shocked by how much the field had progressed. Basically, all the rationalizations that we used to have 20 years ago to explain why things were happening as they did have been proven wrong and replaced with better explanations. Wow. From my dissertation, you could basically take the background discussion and many of the calculation results based on that and just put a big X through it.
I'm a little short on time today to discuss this much further, but I will get into it more next week. For polymer melts, the ramifications of flow-induced crystallization can be quite severe, so it is not just an esoteric topic. 'Til then.