Poly butene physical structure

Most commercial polymers are substantially linear. They have a single chain of mers that forms the backbone of the molecule. Side-chains can occur and can have a major affect on physical properties. An elemental analysis of any polyolefin, (e.g., polyethylene, polypropylene, poly(l-butene), etc.) gives the same empirical formula, CH2, and it is only the nature of the side-chains that distinguishes between the polyolefins. Polypropylene has methyl side-chains on every other carbon atom along the backbone. Side-chains at random locations are called branches. Branching and other polymer structures can be deduced using analytical techniques such as NMR. 

Tacticity measurements can be correlated with reaction mechanisms and physical properties. For example, the incorporation of an electron donor into the polymerization catalyst formulation has been found to increase isotacticity in a propylene-1-butene copolymer [123], and the distribution of propylene and 1-butene contents as a function of molecular weight varied, depending on donor type. External donors, such as dimethox-ysilane, decrease the butene content more than internal electron donors (in this case, di-n-butyl phthalate). Mechanisms of new polymerization reactions, such as the group-transfer copolymerization of methyl methacrylate and lauryl methacrylate, can be elucidated by comparing NMR-derived structural details [124]. The presence of unanticipated peaks in the spectrum of poly(ethylene-co-norbomene) suggest the occurrence of epimerization... 

Radulescu, A. Schwahn, D. Monkenbusch, M Fetters, L.J. Richter, D. (2004). Structural Study of the Influence of Partially Crystalline Poly(Ethylene Butene) Random Copolymers on Paraffin Crystallization in Dilute solutions. Journal of Polymer Science Part B - Polymer Physics, Vol.42, No.l7, pp.3113-3132, ISSN 0887-6266 Radulescu, A. Schwahn, D. Stellbrink, J., Kentzinger, E. Heiderich, M. Richter, D. Fetters, L.J. (2006). Wax Crystallization from Solution in Hierarchical Morphology Templated by Random Poly(Ethylene-co-Butene) Self-Assembhes. Macromolecules, Vol.39, No.l8, pp.6142-6151, ISSN 0024-9297... 

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