Poly viscoelastic behaviour

C, gel point 102°C), 1,3-propanediol(130°Q, 1,4-butanediol (142°Q and 1,6-hexanediol (183 °C). According to Pritchard [143] viscoelastic behaviour of poly(vinyl alcohol)/glycerol gels was investigated by Hirai et aL Results showed that the behaviour of these gels was almost entirely rubber-like. 

Guezala et al. [420] studied the viscoelastic behaviour of solutions of the thermotropic main chain liquid crystalline X7G (see Fig. 160), Le. a copolyester (M 20 kg/mol) of poly(hydroxy benzoic acid) (60%) and poly(ethylene tere-phthalate) (40%) in m-cresoi the material used is non-random with respect to chain structure and domains of poly(hydroxy benzoic acid) have been reported. Solutions were studied, varying in concentration from 2.5 to 45 wt%. Special care was taken to avoid water absorption, because in its presence degradation and/or trans terification might occur. 

Studies of the photo-oxidation and stabilization of poly (but-1-ene) have been reported in a series of papers. " " The products of breakdown of poly(2-methylpropylene) resulting from high-energy and vacuum-u.v. irradiation have been determined. " The effect of u.v. radiation in the presence of oxygen on the viscoelastic behaviour of poly(2-methylpropylene oxide) (3) has been measured. " It was noted that in the absence of oxygen no changes took place. 

Beaudoin, O., Bergeret, A., Quantin, J.C. et al. (1998) Viscoelastic behaviour of glass beads reinforced poly(butylene terephthalate) experimental and theoretical approaches. Compos. Interfaces, 5, 543. 

Noordermeer JaWM, Ferry JD, Nemoto N (1975) Viscoelastic properties of polymer solutions in high-viscosity solvents and limiting high-frequency behaviour. Ill Poly (2-substituted methyl acrylates). Macromolecules 8(5) 672-677 Okamoto H, Inoue T, Osaki K (1995) Viscoelasticity and birefringence of polyisobutylene. J Polym Sci B Polym Phys 33 1409-1416... 

Chauve G, Heux L, Arouini R et al (2005) Cellulose poly(ethylene-co-vinyl acetate) nanocomposites studied by molecular modeling and mechanical spectroscopy. Biomacromolecules 6 2025-2031 Chazeau L, Cavaille JY, Teiech P (1990) Mechanical behaviour above Tg of a plasticized PVC reinforced with cellulose whiskers. A SANS structural study. Polymer 40 5333-5344 Chazeau L, Cavaille JY, Canova G et al (1999a) Viscoelastic properties of plasticized PVC reinforced with cellulose whiskers. J Appl Polym Sci 71 1797-1808 Chazeau L, Paillet M, Cavaille JY (1999b) Plasticized PVC reinforced with cellulose whiskers I. Linear viscoelastic behavior analyzed through the quasi-point defect theory. J Polym Sci Part B Polym Phys 37 2151-2164... 

Various workers have discussed aspects other than those mentioned above in studies of the viscoelastic properties of polymers. These include PVOH [62], hydroxy-terminated polybutadiene [63], styrene-butadiene and neoprene-type blends [64], and polyamidoimides [65]. Other aspects of viscoelasticity that have been studied include relaxation phenomena in PP [66] and methylmethacrylate-N-methyl glutarimide copolymers [67], shear flow of high-density polyethylene [68], Tg of PMMA and its copolymers with N-substituted maleimide [69] and ethylene-vinyl acetate copolymers [70], and creep behaviour of poly(p-phenylene terephthalate) [71] and PE [72]. 

It has been shown that the viscoelastic losses of OH-terminated poly(dimethyl-siloxane), crosslinked with tetra-functional silicates, decreases with increased crosslink density. Furthermore, identical results were obtained when the polymer was crosslinked with y-irradiation, in bulk and in solution this indicates that there is no significant change in the number of interchain entanglements, and these are responsible for the observed losses. Vulcanization studies of poly(di-methylsiloxane)s, y-irradiated up to 500 Mrad, have shown linear correlation of the crosslink density with swelling, indentation and extension behaviour up to 160 Mrad, and exponentially for higher doses. Basic principles for the thermal stabilization of silicone rubbers, filled with carbon blacks and silica, have been discussed and a tentative stabilization mechanism put forward. ... 

Damaceanu Mariana-Dana, Musteata Valentina-Elena, Cristea Mariana, and Brnma Maria. Viscoelastic and dielectric behaviour of thin films made from siloxane-containing poly(oxadiazole-imide)s. Eur. Polym. J. 46 no. 5 (2010) 1049-1062. 

As with other physico-chemical properties of colloidal microgels the rheological behaviour of dispersions distinctly changes in response to environmental stimuli. At low temperatures the viscoelastic properties of poly(NIPAM) microgels change dramatically with temperature [89, 90]. At low temperatures poly(NIPAM) dispersions display elastic-type behaviour as... 

Ilavsky M, Somvdrsky J, Bouchal K and Dugek K (1993) Structure, Equilibrium and Viscoelastic Mechanical Behaviour of Polym ethane Networks Based on TYiisocyanate and Poly(oxypropylene)Diols, Polymer Gels and Networks 1 159-184. 

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