Dynamic Mechanical Thermal Analysis of Polymer Blends

Dynamic Mechanical Thermal Analysis of Polymer Blends 

Jose-David Badia, Laura Santonja-Blasco, Alfonso Martinez-Felipe, and Amparo Ribes-Creus 

The technique of DMTA is a devoted to assessing the viscoelastic response of a material submitted to a mechanical solicitation, as a function of temperature and 

Characterization of Polymer Blends Miscibility, Morphology, and Interfaces, First Edition. 

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Badia Jose-David, Santonja Blasco Laura, Martmez-FeUpe Alfonso, and Ribes-Greus Amparo. Dynamic mechanical thermal analysis of polymer blends. In Characterization of Polymer Blends, Sabu Thomas, Yves Grohens, Parameswaranpillai Jyotishkumar (eds.), 365-392. Weinheim, Germany Wiley-VCH, 2015. 

J2 Dynamic Mechanical Thermal Analysis of Polymer Blends... 

Figure 9.32 Isothermal (173°C) variation of the storage modulus G with time. The blend contains 75% COP, obtained from solution by acetone precipitation and kept under compression at 210-220 C and 4.0 MPa for Imin. Dynamic-mechanical thermal analysis (DMTA) Polymer Labs MKII (8.0 mm X 8.0 cm x 1.5 mm samples) with cantilever clamps [125] and [128]. Reproduced with permission of Elsevier Science Ltd. For explanation see text.

This second group of tests is designed to measure the mechanical response of a substance to applied vibrational loads or strains. Both temperature and frequency can be varied, and thus contribute to the information that these tests can provide. There are a number of such tests, of which the major ones are probably the torsion pendulum and dynamic mechanical thermal analysis (DMTA). The underlying principles of these dynamic tests have been covered earlier. Such tests are used as relatively rapid methods of characterisation and evaluation of viscoelastic polymers, including the measurement of T, the study of the curing characteristics of thermosets, and the study of polymer blends and their compatibility. They can be used in essentially non-destructive modes and, unlike the majority of measurements made in non-dynamic tests, they yield data on continuous properties of polymeric materials, rather than discontinuous ones, as are any of the types of strength which are measured routinely. 

The styrene content affects the crystallinity of ESI (131) for >50% styrene the copolymers are amorphous. As the styrene content is increased from 50 to 70% styrene the Tg increases from -15 °C to 20 °C. Low density foams were made (8) from a blend of 50% of various ESI polymers, 33% of EVA and 17% of azodicarbonamide blowing agent. Thermal analysis showed that the blends, with an ESI having approximately 70% styrene, had a Tg in the range 22 to 30 °C. Dynamic mechanical thermal analysis (DMTA) traces (see Section 5.1) show that these blends... 

After following the microhardness behaviour during the stress-induced polymorphic transition of homo-PBT and its multiblock copolymers attention is now focused on the deformation behaviour of a blend of PBT and a PEE thermoplastic elastomer, the latter being a copolymer of PBT and PEO. This system is attractive not only because the two polymers have the same crystallizable component but also because the copolymer, being an elastomer, strongly affects the mechanical properties of the blend. It should be mentioned that these blends have been well characterized by differential scanning calorimetry, SAXS, dynamic mechanical thermal analysis and static mechanical measurements (Apostolov et al, 1994). 

Using a dynamic mechanical thermal analysis technique the effects of fillers and rubber polarity on the distribution of filler in butadiene/nitrile rubber blends were investigated. Carbon black and silica were the fillers investigated. Filler migration between polymers was also shown. 12 refs. 

Dynamic mechanical thermal analysis is used to measure the variation in elastic and viscous modulus of a material at different temperatures. In addition to being used to test the effect of blending of the polymers with other materials, this technique is used to investigate the effect of degradation on the mechanical properties of the polymer. ... 

Natural rubber based-blends and IPNs have been developed to improve the physical and chemical properties of conventional natural rubber for applications in many industrial products. They can provide different materials that express various improved properties by blending with several types of polymer such as thermoplastics, thermosets, synthetic rubbers, and biopolymers, and may also adding some compatibilizers. However, the level of these blends also directly affects their mechanical and viscoelastic properties. The mechanical properties of these polymer blended materials can be determined by several mechanical instruments such as tensile machine and Shore durometer. In addition, the viscoelastic properties can mostly be determined by some thermal analyser such as dynamic mechanical thermal analysis and dynamic mechanical analysis to provide the glass transition temperature values of polymer blends. For most of these natural rubber blends and IPNs, increasing the level of polymer and compatibilizer blends resulted in an increase of the mechanical properties until reached an optimum level, and then their values decreased. On the other hand, the viscoelastic behaviours mainly depended on the intermolecular forces of each material blend that can be used to investigate the miscibility of them. Therefore, the natural rubber blends and IPNs with different components should be specifically investigated in their mechanical and viscoelastic properties to obtain the optimum blended materials for use in several applications. 

The molecular mobility and microphase separation in blends of crosslinked polyurethane (PUR) and styrene-acrylonitrile (SAN) copolymer were investigated. The PUR and SAN copolymer were prepared by reactive blending with polymer polyols. DSC, thermally stimulated depolarisation currents (TSDC) techniques, dielectric relaxation spectroscopy (DRS) and dynamic mechanical thermal analysis over a wide range of... 

The glass transition (Ta) and melting (Tm) temperature of the pure component polymers and their blends were determined on a Perkin-Elmer (DSC-4) differential scanning calorimeter and Thermal Analysis Data Station (TADS). All materials were analyzed at a heating and cooling rate of 20°C min-1 under a purge of dry nitrogen. Dynamic mechanical properties were determined with a Polymer Laboratories, Inc. dynamic mechanical thermal analyzer interfaced to a Hewlett-Packard microcomputer. The... 

Thermal analysis techniques are used to study the properties of polymers, blends and composites and to determine the kinetic parameters of their stability and degradation processes.Here the property of a sample is continuously measured as the sample is programmed through a predetermined temperature profile. Among the most common techniques are thermogravimetry (TG) and differential scanning calorimetry (DSC). Dynamic mechanical analysis (DMA) and dielectric spectroscopy are essentially extensions of thermal analysis that can reveal more subtle transitions with temperature as they affect the complex modulus or the dielectric function of the material. 

E. (2001) A dynamic mechanical and thermal analysis of unplasticized and plasticized poly (vinyl alcohol)/methyl cellulose blends. L Appl. Polym. Sci., 80, 1825-1834. 

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