Linear lowdensity polyethylene

Fig. 7 Changes in crystallinity near to the surface of a linear lowdensity polyethylene bar exposed to UV in the laboratory for 6 weeks. Samples taken at different depths from the exposed surface. Each sample was 0.1mm deep the corresponding result is plotted at the midpoint of the layer. (More details in Craig, I.H. White, J.R. Crystallization and chemicrystallization of recycled photo-degraded polyethylenes. Polym. Eng. Sci. 2005, 45, 588-595.)...

The chemical iadustry manufactures a large variety of semicrystalline ethylene copolymers containing small amounts of a-olefins. These copolymers are produced ia catalytic polymerisation reactions and have densities lower than those of ethylene homopolymers known as high density polyethylene (HDPE). Ethylene copolymers produced ia catalytic polymerisation reactions are usually described as linear ethylene polymers, to distiaguish them from ethylene polymers containing long branches which are produced ia radical polymerisation reactions at high pressures (see Olefin POLYMERS, LOWDENSITY polyethylene). 

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