Glass-reinforced Thermoplastics Research Articles

Shear Strength of Adhesive Bonding of Plastics Intended for High Temperature Plastic Radiators

The use of adhesive joints has increased in recent decades due to their competitive features in comparison with other joining methods. They can be used in specific applications where there is no possibility to use alternative connection techniques. Adhesive bonding was used to assemble the prototype of a high-temperature car radiator (operated up to 125 °C) with a total of 12,240 plastic tubes. This work aims to estimate the shear strength of different adhesives intended for bonding the plastics used to assemble the above-mentioned high-temperature radiator. Fourteen commercial adhesives were tested with one thermoset plastic (G11 glass fabric epoxy sheets) and two glass-reinforced thermoplastics (polyamide PA66-GF30 and polyphenylene sulfide PPS-GF40). Tests were conducted according EN 1465 to determine tensile lap-shear strength of bonding. Testing showed that only 4 of the 14 adhesives tested exhibit substantial bonding strength at temperatures above 120 °C and only one is resistant at 180 °C. The AS60/AW60 adhesive showed the best results for all three substrates: 1.6 MPa for epoxy sheets and PA66-GF, and 1.4 MPa for PPS-GF40. Additionally, the influence of the surface treatment with cold plasma was evaluated on a clean and activated bonding surface, causing a 30% increase in the shear strength.

Linear viscoelastic analysis of the room-temperature creep behavior of glass-reinforced aromatic and aliphatic thermoplastics

This research investigated the effects of stress and material type on the long-term creep behavior of glass-reinforced thermoplastics. The polymers investigated were PEN, PET, PBT, PP, Nylon-6 and Nylon-66. Each polymer was compounded with 30% glass fiber reinforcement. Viscoelastic design properties were derived from the experimentally measured creep data. Design properties include isochronous stress–strain diagrams, creep modulus charts, and the material constants of the Maxwell linear viscoelastic constitutive equation. Relationships between the design properties and polymer structure are discussed.

Processing and Associated Properties of In Situ Composites Based on Thermotropic Liquid Crystalline Polymers and Thermoplastics

Abstract The concept of generating liquid crystalline polymer (LCP) reinforcing fibrils on an in situ basis has a number of potentially attractive advantages over the use of the more commonly used glass-reinforced composites. The potential advantages include a wider range of processing options, improved surface appearance, recyclability, and lower processing energy requirements. Many of these advantages have been discussed in previous reviews such as those written by Dutta et al. [1] and La Mantia and Valenza [2]. However, to successfully compete with glass-reinforced thermoplastics, in situ composites based on thermoplastics reinforced with thermotropic LCPs (TLCPs) should at least exhibit similar properties to injection-molded glass-reinforced thermoplastics. One purpose of this review is to address the advantages and disadvantages of in situ composites, and the other is to provide some standards for comparison against more commonly used composites.

Effect of Water Immersion on Fiber/Matrix Adhesion in Thermoplastic Composites

Continuous-fiber-reinforced thermoplastics were tested for the effect of water immersion on fiber/matrix adhesion. The materials evaluated were E/PPS, AS4/PPS, E/J2, AS4/J2, S2/PEEK, AS4/PEEK, S2/PEKK, AS4/PEKK, and S2/ VECTRA. These materials were tested in uniaxial compression, transverse flexure, and short beam shear, both dry- and water-conditioned. Scanning electron microscopy was used to assess the quality of the fiber/matrix bond. The carbon-reinforced materials re tained adhesion after immersion. However, the glass-reinforced thermoplastics were, in general, degraded by water, which hydrolyzed the fiber/matrix bond and sig nificantly reduced the mechanicai properties.

The Effects of Simulated Fire Exposure on Glass-Reinforced Thermoplastic Materials

The influence of a modest thermal insult from a fire on glass-reinforced thermoplastics is explored experimentally and analytically. A first-order thermomechanical model was formulated to investigate the thermomechanical response of asymmetrically heated glass-reinforced, thermo plastic composites under tensile load. Failure predictions can be summarized with a three- dimensional failure surface comprised of load, heatflux and time-to-failure for composite material systems exposed to localized overheating. This paper provides an overview of the preliminary results from a series of small-scale experiments and application of a thermomechanical model.

Thermal and Environmental Resistance of Glass-Reinforced Thermoplastics

Thermal and Environmental Resistance of Glass-Reinforced Thermoplastics

Flexural fatigue of glass-reinforced thermoplastics: Polymer Engineering and Science, Vol 9, No 5, p 339 (September 1969)

The fatigue failure of thermoplastics and glass-reinforced thermoplastics is a function of cyclic stress or deflection level, test frequency, viscoelastic polymer parameters and matrix-to-fiber stress transfer. This paper reports an investigation of the modes of high frequency fatigue failure in glass-reinforced and unreinforced thermoplastics. In particular the effects and control of dissipative heating of a working specimen and the role of efficient matrix-to-fiber stress transfer are considered. A test procedure with which the severity of dissipative heating can be continuously followed and controlled during an accelerated fatigue test is described.

Flexural fatigue of glass-reinforced thermoplastics: Cessna, L. C. Levens, J. A. and Thomson, J. B. Polymer Engineering and Science, Vol 9, No 5, p 339 (September 1969)

Flexural fatigue of glass-reinforced thermoplastics: Cessna, L. C. Levens, J. A. and Thomson, J. B. Polymer Engineering and Science, Vol 9, No 5, p 339 (September 1969)