Ultra high modulus

Ciferri, A. and Ward, I.M. (eds.) (1979) Ultra-High Modulus Polymers (Applied Science Publishers, London). 

Miscibility or compatibility provided by the compatibilizer or TLCP itself can affect the dimensional stability of in situ composites. The feature of ultra-high modulus and low viscosity melt of a nematic liquid crystalline polymer is suitable to induce greater dimensional stability in the composites. For drawn amorphous polymers, if the formed articles are exposed to sufficiently high temperatures, the extended chains are retracted by the entropic driving force of the stretched backbone, similar to the contraction of the stretched rubber network [61,62]. The presence of filler in the extruded articles significantly reduces the total extent of recoil. This can be attributed to the orientation of the fibers in the direction of drawing, which may act as a constraint for a certain amount of polymeric material surrounding them. 

Ward, I. M. The Preparation, Structure and Prooperties of Ultra-High Modulus Flexible Polymers. Vol. 70, pp. 1 —70. 

Biro. D.A.. Plcizeicr, G. and Deslandes, Y. (1993a). Application of the microbond technique. HI. Efl ecls of plasma treatment on the ultra-high modulus polyethylene fiber-epoxy interface, J. Mater. Sci. Lett. II, 698-710. 

Cifferi A, Ward JM (eds) Ultra-high modulus polymers. Elsevier, London, chap 11... 

A. Ciferri and 1. M. Ward, eds., Ultra-High Modulus Polymers, Burgess-lntl Ideas, Englewood, N.J. (1979). 

Peterlin, A., in Ultra-high Modulus Polymers, Ciferri, A., Ward, I. M. (eds.), p. 279, London Applied Science Publishers 1979... 

Ultra-high modulus fibers such as aramid and carbon fibers have been currently utilized for composite material fabrication. Ultra-high modulus polyethylene (UHMPE) fiber is also applicable for composite fabrication because of the light weight in addition to its high modulus, vibration damping, and resistance to chemicals. However, this fiber has drawbacks such as poor interfacial adhesion with the polymer matrix of the composite because of highly hydrophobic nature of the fiber surface. 

Recently, various techniques that produce highly oriented linear polyethylene with a ultra high modulus (hereafter, referred to as UHMPE) have been developed. In this section, we will examine the structure of the UHMPE that was prepared by highly drawing a dried gel [69]. Even if bulk polyethylene is uniaxially highly drawn by a normal method at a temperature between the Tg and Tm, the phase structure is essentially similar to the undrawn sample. That is, it involves three phases of the crystalline and two noncrystalline phases, although the mass fraction and detailed content of each phase are somewhat different. However, UHMPE samples may have a particular phase structure. 

G. Capaccio and I. M. Ward, Ultra-high Modulus Linear Polyethylene through Controlled Modulus Weight and Drawing, Polym. Eng. Sci., 15, 219-224 (1975). 

IS - isotropic, OR - oriented, CD - cold drawn, CM - compression moulded, QR - quenched rolled, UHM - ultra high modulus, UHO - ultra highly oriented... 

De Gennes scaling concepts for polymer solutions and melts and the concept of reptation movement of polymer chains in melts Pennings discovery of chain extension and shish-kebab formation in stirred solutions of very high MW polyethylene this eventually led to the ultra-high modulus gel-spinning process of polyethylene... 

Ciferri A and Ward IM (Eds), "Ultra-high Modulus Polymers,", Applied Science Publishers, London, 1979. 

Pennings AJ and Meihuizen KE, in Ciferri and Ward (Eds), (see General references) "Ultra-high Modulus Polymers", p 117,1979. 

Amoco has developed a family of ultra high modulus continuous graphite fibers and preforms with axial thermal conductivity to llOOW/mK. The extremely high thermal conductivity is a direct result of an extremely high degree of crystallinity during carbonization of the mesophase pitch precursor fiber. Table... 

Capaccio, G., A.G. Gibson and I.M. Ward (1979) in Ultra-High Modulus Polymers, Elsevier, London, p. 1. 

The Preparation, Structure and Properties of Ultra-High Modulus Flexible Polymers... 

---