Polymer crystallisation

Polymer crystallisation is astonishing in that normally flexible long molecular chains can align to form crystals that compete with diamond in their order and beauty. Polyethylene crystallisation is commercially very, very important but has also served as a template to help understand the way in which natural and human polymers can also crystallise. On reflection I now realise just how lucky I was to work for a PhD under the guidance of two great scientist Andrew Keller, who dedicated his life almost exclusively to the understanding of polymer crystallisation and Sir Charles Frank who had many scientific interests including crystallisation.

Most of my polymer crystallisation work took place at Bristol University between 1970-1976. Crystallisation is  also part of the High Modulus Polyethylene (HMP) story (1970-1990s) that is told in the Innovation section of this web site.

The development of the Multpass Rheometer (MPR) apparatus resulted in renewed interest in crystallisation using both insitu XRay and optical techniques for the studies on the effect of flow on polyethylene melt crystallisation

There have been other excursions into crystallisation with Sopark Sonwai, (Cocoa Butter) and Nuno Reis (Proteins).

A summary presentation on the crystallisation of polyethylene.

A recent seminar presentation is relevant to crystallisation during flow.

Papers relevant to Crystallisation

• M.R.Mackley and A. Keller. Flow induced crystallization of polyethylene melts.Polymer. 14, 16-20 (1973).
• A Keller and M.R. Mackley. Chain orientation and crystallization. Pure and Applied. Chem. 39, 195-224 (1974).
• M.R.Mackley. Hydrodynamic factors affecting the growth of fibrous crystals of extended-chain Polymers. Proc. Int. Conf. on Theoretical Rheology (Cambridge).  Ed.J.R.A.Pearson (1974).
• M.R.Mackley.   Shish Kebabs: An experimental preparation. Colloid and Polymer. Sci. 253, 261-263 (1975).
• M.R.Mackley.  Shish Kebabs: Hydrodynamic factors affecting their crystal growth. Colloid and Polymer. Sci. 253, 373-379 (1975).
• M.R.Mackley and A. Keller. Flow induced polymer chain extension and its relationship to fibrous crystallization. Part 1 , Part 2  Phil. Trans. Royal Soc. (Lond.) 278, 29-66 (1975).
• M.R.Mackley, F.C. Frank and A. Keller. Flow induced crystallization of polyethylene melts. Journal of Materials Science. 10, 1501-1509 (1975).
• M.R.Mackley. Crystallization of flowing melts. Proc. Int. Conf. on Polymer Rheology and Plastic Processing (Loughborough) (1976).
• M.R.Mackley. Polymer fluids. Sir Charles Frank Festschrift; Ed. R.G. Chambers et al. Polymer Fluids. Adam Hilger, 307-321 (1991).
• P.Gao and M.R. Mackley. The effect of presolvent loading on the ultimate drawability of ultra high molecular weight polyethylene. Polymer. 32, 17, 3136-3139 (1991).
• M R Mackley, G D Moggridge and O Saquet Direct experimental evidence for the preferential growth of flow induced fibrous polymer crystallisation occurring at a solid / melt interface. J Material Science. 35, 20  5247-5254 (2000)
• S. Sonwai and M.R. Mackley The Effect of Shear on the Crystallization of Cocoa Butter. Journal of American Oil Chemists Society.  JAOCS  83(7), 583-596  (2006)
• D.G.Hassell and M.R.Mackley. Localised flow-induced crystallisation of a polyethylene melt. Rheologica  Acta. 47, Nos 9   435-446 (2008)
• L. Scelsi & M. R. Mackley Rheo-optic flow-induced crystallisation of polypropylene and polyethylene within confined entry–exit flow geometries Rheologica  Acta 47. 895–908 (2008)
• L. Scelsi, M. R. Mackley, H. Klein, P. D. Olmsted, R. S. Graham, O. G. Harlen, and T. C. B. McLeish.  Experimental observations and matching viscoelastic specific work predictions of flow-induced crystallization for molten polyethylene within two flow geometries Journal of Rheology 53,4, 859-876 (2009)
• N. M. Reis, Y Dimitri, B Chirgadze T. L. Blundell and M. R. Mackley The effect of protein–precipitant interfaces and applied shear on the nucleation and growth of lysozyme crystals Acta Cryst. D65, 1127–1139 (2009)