Polyvinyl viscoelastic properties

The paper discusses the application of dynamic indentation method and apparatus for the evaluation of viscoelastic properties of polymeric materials. The three-element model of viscoelastic material has been used to calculate the rigidity and the viscosity. Using a measurements of the indentation as a function of a current velocity change on impact with the material under test, the contact force and the displacement diagrams as a function of time are plotted. Experimental results of the testing of polyvinyl chloride cable coating by dynamic indentation method and data of the static tensile test are presented. 

Ninomiya,K., Ferry,J.D., Oyanagi,Y. Viscoelastic properties of polyvinyl acetates. II. Creep studies of blends. J. Phys. Chem. 67,2297-2308 (1963). 

Oyanagi,Y., Ferry, J.D. Viscoelastic properties of polyvinyl acetates. IV. Creep studies of plasticized fractions. J. Colloid Sci. 21, 547-559 (1966). 

Effect of Plasticization on Viscoelastic Properties of Polyvinyl Chloride... 

Figure 9.12 Temperature dependence of storage and loss moduli for a polyvinyl chloride-nitrile bidadiere rubber film bonded in parallel to a polyvinyl chloride film. Takayanagi model type (a) gives better fit to experiment. (Reproduced from Takayanagi, M. (1963) Viscoelastic properties of crystalline polymers. Memoirs of the Faculty of Engineering Kyushu Univ., 23,41. Copyright (1963) Kyushu University.)...

The effect of water absorption on the viscoelastic properties of glass fibre reinforced polyester and polyvinyl ester composites has been investigated using DMA by Fraga et al [ 481. These workers contrasted the water absorption behaviour of the pure, unfilled polymers with composites at two temperatures (40°C and 80°C) and evaluated the relative degree of hydrothermal degradation that occurred. 

The mechanical properties of LDPE fall somewhere between rigid polymers such as polystyrene and limp or soft polymers such as polyvinyls. LDPE exhibits good toughness and pHabiUty over a moderately wide temperature range. It is a viscoelastic material that displays non-Newtonian flow behavior, and the polymer is ductile at temperatures well below 0°C. Table 1 fists typical properties. 

This technique has found the following applications in addition to those discussed in Sections 10.1 (resin cure studies on phenol urethane compositions) [65], 12.2 (photopolymer studies [66-68]), and 13.3 (phase transitions in PE) [66], Chapter 15 (viscoelastic and rheological properties), and Section 16.4 (heat deflection temperatures) epoxy resin-amine system [67], cured acrylate-terminated unsaturated copolymers [68], PE and PP foam [69], ethylene-propylene-diene terpolymers [70], natural rubbers [71, 72], polyester-based clear coat resins [73], polyvinyl esters and unsaturated polyester resins [74], polyimide-clay nanocomposites [75], polyether sulfone-styrene-acrylonitrile, PS-polymethyl methacrylate (PMMA) blends and PS-polytetrafluoroethylene PMMA copolymers [76], cyanate ester resin-carbon fibre composites [77], polycyanate epoxy resins [78], and styrenic copolymers [79]. 

The commonly used thermoplastic piping materials are viscoelastic materials and demonstrate time-dependent physical properties. These materials include unplasticized polyvinyl chloride (U-PVC)... 

---