Ultra-high molecular weight method

McKellop, H. Shen, F.W. Lu, B. Salovey, R. Campbell, P. The effect of sterilization method and other modifications on the wear resistance of acetabular cups of ultra-high molecular weight polyethylene. A hip simulator study. J. Bone and Joint Surgery 2000, 82 (12), 1708-1725. 

Muratoglu, O.K. Bragdon, C.R. O Connor, A.S. Jasty, M. Harris, W.H. A novel method of cross-linking ultra-high molecular-weight polyethylene to improve wear reduce oxidation, and retain mechanical properties. J. Arthoplasty 2001, 16, 149-160. 

The timescales associated with this brute-force equilibration are on the order of the time it takes a polymer to diffuse a distance approximately equal to its size, which can be prohibitively large for ultra high molecular weight polymers. Alternate, more rapid methods for polymers with ends, like the connectivity altering algorithms, have been in existence for almost two decades (Alexiadis et al., 2008 Baig et al., 2010 Daoulas et al., 2005 de Pablo... 

McKellop H.A., E.W. Shen, P. Campbell, and T. Ota. 1999. Effect of molecular weight, calcium stearate, and sterilization methods on the wear of ultra-high molecular weight polyethylene acetabular cups in a hip simulator. / Orthop Res 17 329-339. 

ASTM F 2183-02. 2002. Standard test method for small punch testing of ultra-high molecular weight polyethylene used in surgical implants. West Conshohocken, PA American Society for Testing and Materials. 

Poly Hi Solidur Plastics India Limited [4] developed products for use on the Indian Railways based on ultra-high molecular weight PE (UHMWPE Hoechst s Hostalen GUR). The base polymer is mixed with patented additives and uses a computer controlled sintering process and sophisticated fabrication methods to produce a material which is claimed to have much higher values for a number of technically important properties such as wear, chemical and water resistance, impact strength and dynamic coefficient of friction. The growth of the market for UHMWPE products is briefly discussed, and the applications targeted by Poly Hi Solidur Plastics are discussed. 

Lukhovitskii and Karpo [191] established that, in the concentration range accessible for viscometry, the efflux time of a polymer solution is a linear function of the polymer concentration. This is consistent with the Einstein-Simha equation. In the general case, the efflux time of a solution with a polymer concentration tending to zero, T, does not coincide with the efflux time of the pure solvent, T, When the efflux time of a polymer solution is reduced by rather than by (as is done in the standard method), the reduced viscosity becomes independent of the polymer concentration and equal to the intrinsic viscosity. The advantages of the proposed method are especially important for the determination of the intrinsic viscosity (M ) of ultra-high molecular weight polymers. 

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