Abstract
A study has been made on the longitudinal growth of fibrillar polyethylene crystals from xylene solutions subjected toPoiseuille flow. Fibrillar crystal seeds were placed at the entrance of a capillary through which a supercooled xylene solution of polyethylene was allowed to flow and the longitudinal growth in the chain direction was investigated. By winding the growing crystal on a roll with a speed equal to the growth rate, continuous fibrillar crystals could be produced. Scanning electron microscopic examinations have shown that the continuous polyethylene crystals can be regarded as assemblies of elementary fibrils of the Shish-Kebab type. Growth was found to be nucleated at the lateral surface of the seed crystals instead of at the end. Under static conditions a tapered shaped crystal develops which allows the determination of the total length of the grown fiber for a growth period of time and thereby the growth rate. The latter quantity was found to increase with flow rate, polymer concentration and degree of supercooling.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
