Modulus poly

Day, R.J., Robinson, I.M., Zakikhani, M. and Young, R.J. (1987). Raman spectroscopy of stresses high modulus poly(/)-phenylene benzobislhiazole) fibers. Polymer 2S, 1833-1840. 

Fig. 23. Normalized reciprocal steady-state recoverable compliance Je,max/Je for three polymers, poly(dimethyl siloxane), PIB, and PS, versus the reduced temperature T/Tg Tg is the glass temperature and the normalized compliance

The breaking strengths of the ultra high modulus poly-ethylenes are very dependent on strain rate and temperature. 

Imai, Y. Nishimura, S. Abe, E. Tateyama, H. Abiko, A. Yamaguchi, A. Aoyama, T. Taguchi, H. High modulus poly(ethylene terephthalate)/expandable fluorine mica nanocomposites with a novel reactive compatiblizer. Chem. Mater. 2002, 14, 477-479. 

RJ Day, IM Robinson, M Zakikhani, RJ Young. Raman spectroscopy of stressed high modulus poly(/7-phenylene benzobisthiazole) fibres. Polymer 28 1833-1840, 1987. 

R.J. Day, I.M. Robinson, M. Zakikhani, and R.J. Young, Raman Spectroscopy of stresses high modulus poly(p-phenylene benzobisoxazole) fibers. Polymer, 1987, 28 p. 1833 -1840... 

Figure 3.16 Some experimental dynamic components, (a) Storage and loss compliance of crystalline polytetrafluoroethylene measured at different frequencies. [Data from E. R. Fitzgerald, J. Chem. Phys. 27 1 180 (1957).] (b) Storage modulus and loss tangent of poly(methyl acrylate) and poly(methyl methacrylate) measured at different temperatures. (Reprinted with permission from J. Heijboer in D. J. Meier (Ed.), Molecular Basis of Transitions and Relaxations, Gordon and Breach, New York, 1978.)...

Fig. 3. Effect of density on compressive modulus of rigid cellular polymers. A, extmded polystyrene (131) B, expanded polystyrene (150) C-1, C-2, polyether polyurethane (151) D, phenol—formaldehyde (150) E, ebonite (150) E, urea—formaldehyde (150) G, poly(vinylchloride) (152). To convert...

Poly(methyl methacrylate). PMMA offers distinct advantages over BPA-PC with respect to significandy lower birefringence, higher modulus, and lower costs, but has not been successhil as a material for audio CDs and CD-ROM as well as a substrate material for WORM and EOD disks because of its high water absorption (which makes it prone to warp) and its unsuitabiUty for metallising, and less so because of its low resistance to... 

Fig. 26. Qualitative compatison of substrate materials for optical disks (187) An = birefringence IS = impact strength BM = bending modulus HDT = heat distortion temperature Met = metallizability WA = water absorption Proc = processibility. The materials are bisphenol A—polycarbonate (BPA-PC), copolymer (20 80) of BPA-PC and trimethylcyclohexane—polycarbonate (TMC-PC), poly(methyl methacrylate) (PMMA), uv-curable cross-linked polymer (uv-DM), cycHc polyolefins (CPO), and, for comparison, glass.

As with poly(ethylene terephthalate) there is particular interest in glass-fibre-filled grades. As seen from Table 25.8, the glass has a profound effect on such properties as flexural modulus and impact strength whilst creep resistance is also markedly improved. 

Class and Chu [34] have studied the tackification of natural rubber and SBR over a wide range of resin concentrations for several tackifiers. From their graphical data it can be estimated that 1 1 tackification (by weight) with a poly(/-butyl styrene) resin, MW 850 and Tg = 59°C, gives a PSA with Tg about — 13°C, and storage modulus, G about 8.8 x 10 Pa, well within the PSA window. 

Most moisture-curing liquid adhesives utilize poly(oxypropylene) (PPG) polyols, as shown above. These raw materials produce among the lowest-viscosity prepolymers but may not have sufficient modulus at higher temperatures for some applications. A certain percentage of polyester polyols may also be utilized to boost performance, but these may cause a large increase in viscosity, and so they are more often used in conjunction with polyether polyols to provide a high-performance adhesive with workable viscosities. Poly(butadiene) polyols may be utilized for specific adhesion characteristics. 

In most ionomers, it is customary to fully convert to the metal salt form but, in some instances, particularly for ionomers based on a partially crystalline homopolymer, a partial degree of conversion may provide the best mechanical properties. For example, as shown in Fig. 4, a significant increase in modulus occurs with increasing percent conversion for both Na and Ca salts of a poly(-ethylene-co-methacrylic acid) ionomer and in both cases, at a partial conversion of 30-50%, a maximum value, some 5-6 times higher than that of the acid copolymer, is obtained and this is followed by a subsequent decrease in the property [12]. The tensile strength of these ionomers also increases significantly with increasing conversion but values tend to level off at about 60% conversion. 

---