DYNAMIC MECHANICAL PROPERTIES OF POLYVINYL ACETATE IN SHEAR IN THE GLASS TRANSITION TEMPERATURE RANGE

1963 ◽  
Vol 67 (1) ◽  
pp. 152-161 ◽  
Author(s):  
A. J. Kovacs ◽  
Robert A. Stratton ◽  
John D. Ferry
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Polyvinyl Acetate ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
Temperature Range

Vinylpyridinium ionomers. III. Influence of the matrix glass transition temperature on the dynamic mechanical properties of random acrylate-based systems

1990 ◽  
Vol 68 (7) ◽  
pp. 1228-1232 ◽  
Author(s):  
Denis Duchesne ◽  
Adi Eisenberg
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Butyl Acrylate ◽  
Matrix Material ◽  
Ethyl Acrylate ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
The Matrix

The thermal and dynamic mechanical properties of random butyl acrylate- and plasticized ethyl acrylate-based vinylpyridinium ionomers have been investigated. The properties of the ionomers were found to be dependent on the glass transition temperature of the matrix material. Ionomers having a glass transition temperature lower than ca. 25 °C exhibited all the features associated with the presence of phase-separated microdomains or clusters while the materials with higher glass transition temperatures were not. It was also observed that the dispersion associated with the vinylpyridinium clusters for a butyl acrylate-based ionomer with 12 mol% of ionic units occurs at ca. 25 °C. This value is very close to that observed previously by Otocka and Eirich in their study of a butadiene-based vinylpyridinium ionomer with the same ion content. Keywords: ionomers, plasticization, clustering, glass transition, dynamic mechanical properties.

The Effects of Chemical Resistance for Nanocomposite Materials via Nano-Silica Addition into Glass Fiber/Epoxy

2013 ◽  
Vol 853 ◽  
pp. 28-33
Author(s):  
Huey Ling Chang ◽  
Chih Ming Chen ◽  
Kung Liang Lin ◽  
Bor Kae Chang
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Glass Fiber ◽  
Epoxy Resin ◽  
Storage Modulus ◽  
Chemical Resistance ◽  
Dynamic Mechanical Properties ◽  
Silica Nanopowder

Nanocomposite samples containing epoxy resin, glass fiber and 0~2 wt.% SiO2 nanopowder are prepared. The effects of SiO2 addition on the chemical resistance, glass transition temperature (Tg) and dynamic mechanical properties of the various samples are then observed. The chemical resistance of the nanocomposite specimens is compared with that of pure glass fiber/epoxy composite specimens when tested in acetone. The results show that the addition of 2 wt.% SiO2 increases the value of storage modulus by 1646MPa compared to that of the sample containing no silica nanopowder. Following immersion in acetone, all the nanocomposite specimen storage modulus decreased, but the addition of SiO2 reduced the decline, where the 2 wt. % samples decrease from 11.76% reduction to 0.84% and no significant change in the Tg compared to that of the sample with no silica nanopowder. Therefore, the experimental results indicate that 2 wt.% SiO2 addition is beneficial in improving chemical resistance, glass transition temperature, and dynamic mechanical properties of epoxy resin / glass fiber nanocomposites.

scholarly journals Optimizing Viscoelastic Properties of Rubber Compounds for Ballistic Applications

2020 ◽  
Vol 10 (21) ◽  
pp. 7840
Author(s):  
Janis Karl ◽  
Franziska Kirsch ◽  
Norbert Faderl ◽  
Leonhard Perko ◽  
Teresa Fras
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Mechanical Stress ◽  
Mechanical Load ◽  
Superposition Principle ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Ballistic Impact ◽  
Dynamic Mechanical

Using interlayers of rubber adds a positive effect to the synergy of disruptor–absorber armors. Emerging from its viscoelasticity the material is able to transform mechanical stress into heat. The dynamic mechanical properties of elastomers depend on both ambient temperature and frequency of an applied mechanical load. The damping shows a maximum in the glass transition area. If the frequency of the glass transition is in the magnitude of the mechanical stress rate applied by ballistic impact, the elastomer will undergo the transition and thus show maximized damping. An ideal material for ballistic protection against small calibers is developed by making use of dynamic mechanical analysis and the time–temperature superposition principle. The material is later analyzed by ballistic experiments and compared to other nonideal rubbers with regard to glass transition temperature, hardness and damping. It is shown that by choosing a material correctly with certain glass transition temperature and hardness, the ballistic properties of a steel–rubber–aluminum armor can be enhanced. The chosen material (butyl rubber) with a hardness of 50 °ShA is able to enhance energy absorption during ballistic impact by around 8%, which is twice as good as other rubber with non-optimized properties.

A Comparative Study on Dynamic Mechanical Properties of Radial and Chordwise Direction of Bamboo

2013 ◽  
Vol 838-841 ◽  
pp. 2227-2230
Author(s):  
Chun Gui Du ◽  
Ren Li ◽  
Zhe Wang ◽  
Hong Wei Yu ◽  
Chun De Jin
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Dynamic Mechanical Analysis ◽  
Radial Direction ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Dynamic Mechanical ◽  
Environment Temperature

The dynamic mechanical properties of radial and chordwise bamboo pieces were tested by dynamic mechanical analysis (DMA). The results show that the storage modulus and loss modulus and tangent delta of chordwise direction were all larger than the radial direction of bamboo; the peak of glass transition temperature of chordwise direction is high than the radial direction, and their sizes are very close; dynamic mechanical analysis can provide a reference for the optimization applicable environment temperature of curtain plybamboo.

Effects of Nano-Silica Addition and Reactive Diluent Addition on Dynamic Mechanical Properties of Epoxy Nanocomposites

2013 ◽  
Vol 853 ◽  
pp. 46-52
Author(s):  
Huey Ling Chang ◽  
Chih Ming Chen
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Reactive Diluent ◽  
Dynamic Mechanical ◽  
Silica Nanopowder

Epoxy resin nanocomposite samples containing 0~3wt.% reactive diluent and 0~3wt.% silica nanopowder are prepared. The preparation process is presented for solvent-free and greenmanufacturing. The storage modulus, loss modulus and glass transition temperature of the various samples are then evaluated via Dynamic Mechanical Analysis (DMA). For samples containing 0wt.% and 3wt.% reactive diluent, respectively, 3wt.% nanoSiO2 addition is found to increase the storage modulus by 51.06 % and 22.22 %, respectively. In addition, it is found that the loss modulus is determined principally by the level of SiO2 addition, whereas the glass transition temperature is determined mainly by the level of reactive diluent addition.

Study on Film of Polyvinyl Acetate Emulsion Modified by Starch

2011 ◽  
Vol 403-408 ◽  
pp. 80-83 ◽  
Author(s):  
Yan Hua Zhang ◽  
Ji You Gu ◽  
Hai Yan Tan ◽  
Ming Wei Di ◽  
Zhi Guo Li ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Polyvinyl Acetate ◽  
Dynamic Mechanical Properties ◽  
Film Distribution ◽  
Film Forming ◽  
Emulsion Film ◽  
Composite Mechanics ◽  
Improve Water Resistance

The use of starch on polyvinyl acetate emulsion blend modified in order to achieve improved film toughness, which aims to improve water resistance and film-forming emulsion adhesive performance. Dynamic mechanical properties (DMA), scanning electron microscopy (SEM) method was used to analyze the dynamics of film emulsion blend composite mechanics, the distribution of latex particles and glass transition temperature. The results show that: with pure polyvinyl acetate (PVAc) compared to starch-modified film-forming emulsion film distribution, glass transition temperature of the homopolymer emulsion up to 30°C.

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