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Tool handles
accumulation of composite materials during impact loading. The effect of rate on Mode II interlaminar fracture toughness in carbon fibre-reinforced PEEK (APC-2) and carbon fibre-reinforced epoxy (AS4/3501-6) laminates was examined, End-notched flexure test geometry was employed for the experiments, which were carried out at room temperature over an extensive range of cross-head speeds. The APC-2 material exhibited ductile crack growth at rates < 3,2 × 10-4 m s-1 and brittle crack growth at higher speeds. The epoxymatrix composites exhibited brittle crack growth at all rates. Rice husk ash filled-polyester resin composites Chand, N,, Dan, T.K., Verma, S. and Rohatgi, P. S. Journal of Materials Science Letters Vol 6 No 6 (June 1987) pp 733-735 Tensile and impact properties are evaluated for rice husk ash-filled polyester with different ash volume fractions. The decrease in strength with increasing ash volume fraction is due to the weakness of rice husk ash in tension; SEM observations suggest that porosity increases with increasing ash content. Impact strength also decreases with ash content. Increasing the temperature at which the rice husk is fired has no effect on tensile strength but decreases impact strength. The role of aminosilanes on the adhesion promotion at the E/glass/poly(butylene terephthalate) interface Ishida, H. and Nakata, K. SAMPE Quarterly Vol 18 No 3 (April 1987) pp 21-28 The interaction between poly(butylene terephthalate) (PBT) and -t-amino propyltriethoxysilane (7-APS) and PBT and other silane coupling agents was investigated by Fouriertransform infrared spectroscopy. It was found that the thermal degradation of PBT was catalysed by the 7-APS and this was attributed to the presence of the amine group. The flexural
strength and tensile strength of composites formed from glass flake-reinforced PBT in which the flakes had been treated with the various coupling agents were then determined, and it was found that the PBT composite reinforced with 7-APS treated glass flakes had better mechanical properties than those that had been treated with other coupling agents. This gives support to the suggestion that the catalytic effect of the 7-APS is important for the improvement of mechanical properties.
Styrene-terminated polysulfone oligomers as matrix material for graphite reinforced composites; an initial study Garcia, D., Bowles, K,J. and Vannucci, ILD. SAMPE Quarterly Vol 18 No 4 (July 1987) pp 1-9 Styrene-terminated polysulphone oligomers are offered as candidate matrix materials for graphite fibre-reinforced composites. The processing parameters and properties of the resulting composites are described. CH2C12 is found to be the best solvent for prepregging. The composites are shown to exhibit similar mechanical properties to 177°C cure epoxy matrix composites but to have better retention of these properties in hot/wet environments.
Tensile strength of chopped-fiber reinforced SMC composites with circular cut-outs Chaturvedi, S.K. and Keshavarz-Valian, A. SAMPE Quarterly Vol 18 No 3 (April 1987) pp 1-9 Uniaxial tensile strength tests were carried out on specimens of SMC-R50 and SMC-R65 (SMC containing 50% and 65%, respectively, of chopped glass fibres, 25.4 m m long). Both materials were found to exhibit the 'hole-size effect'. However, results for the R65 material showed a good correlation with the strength predictive models based on linear elastic
fracture mechanics and on the point stress criterion, whereas those for R50 did not. Temperature dependence of hydrothermal ageing of CSM-laminate during water immersion Phani, K.K. and Bose, N.R. Composites Science and Technology Vol29 No 2 (1987) pp 79-87 Random glass fibre (E-glass CSM)-reinforced isophthalic polyester resin specimens were stored in hot distilled water baths maintained at various temperatures. Effects of the environmental history on strength characteristics of the composites were investigated by three-point bending tests and the degradation studied by micro-observation. The study shows that the hydrothermal degradation of the laminates is a rate process for which the temperature influences only the rate constant, and the rate constant follows an Arrhenius equation. Thus, using this equation, if the activation energy of the degradation process is known, it will be possible to estimate the slreiagth at any temperature from experiments conducted at only one temperature. Thermally induced stresses and deformation in angle ply composite tubes Hyer, M.W. and Rousseau. C.Q. Journal of Composite Materials Vol 21 (May 1987) pp 454480 The effects of a uniform temperature change, from cure, on the stresses, axial expansions and thermally induced twist on four designs of angle-ply tubes made of P775/934 are investigated. Hybrid tubes using T300/934 in the off-axis layers and P775/934 in the axial layers were also studied. It was found that the tube design had only a minor influence on the stresses, axial stiffness and axial thermal expansion; instead it influenced the thermally induced twist and torsional stiffness. These proportions were also found to be dependent on the off-axis angle and the material selected.
ai atr"ac of Abstracts of Britt'sh Patents are prepared by Dr F.R. Jones, Department of Ceramics, Glasses and Polymers, Univers/ty of Shelf/e/d, UK
UK PATENTS
COMPONENTS Composite integral car body (Jinsheng, T of China) GB2177973A (4February 1987) A h a n d l a y - u p p o l y e s t e r G R P o n t o a foam mould is described. Tool handles (Fabien, RL. of UK) GB 2 186 578A (19August
1987) A unidirectional G R P sparis used as a stiffening core for a wooden handle. Billiard cue with hollow body and foamed core (Tsai, S.-K. ofTaiwan) GB 2187 646 A (16 September 1987) The cue consists of a hollow rolled FRP tube filled with a foamed core.
COMPOSITES. JANUARY 1 9 8 8
Articles of filled synthetic polymeric materials and glass bead filler therefor (Glaverbel, Belgium)GB 2 188 935,4 (14 October 1987) Coated glass bead fillers a re described. The coating must have a Tg at least 15°C lower than the m atrix to endow impact resistance to the articles.
MATERIALS Liner material (Bristol Composite materials Engineering Ltd, UK) GB 2 185 438A (22July 1987) A mineral fibre-particulate woven or non-woven paper-reinforced phenolic liner for aircraft structures is described. Honeycomb materials (H.R. Smith (Technical Developments) Ltd, UK) GB 2 188 866 A (14 October 1987) A method of manufacturing a polymeric honeycomb structure from non-reinforced or fibrereinforced advanced thermoplastic layers (eg, PES or PEEK) is claimed.
PROCESSES Pultrusion method (FiberforceLtd, UK) GB 2 186 833A (26August 1987) A strippable extruded thermoplastic coating is used to produce a pultruded profile with a smooth surface. A method of improving the oxidation resistance of graphites (The Plessey Co plc, UK)GB2187178A (3September 1987) The title claim is achieved by vacuum impregnation of an aqueous refractory precursor which forms a protective film by hydrolysis, thermal decomposition or chemical reaction. Aluminium nitrate is described. Moulding fibre reinforced articles (Advanced Composite Components Ltd, UK) GB 2 187 672 A (16 September 1987) A method of forming a conformed layer of armour onto an article using prepreg technology is described.
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strength and tensile strength of composites formed from glass flake-reinforced PBT in which the flakes had been treated with the various coupling agents were then determined, and it was found that the PBT composite reinforced with 7-APS treated glass flakes had better mechanical properties than those that had been treated with other coupling agents. This gives support to the suggestion that the catalytic effect of the 7-APS is important for the improvement of mechanical properties.
Styrene-terminated polysulfone oligomers as matrix material for graphite reinforced composites; an initial study Garcia, D., Bowles, K,J. and Vannucci, ILD. SAMPE Quarterly Vol 18 No 4 (July 1987) pp 1-9 Styrene-terminated polysulphone oligomers are offered as candidate matrix materials for graphite fibre-reinforced composites. The processing parameters and properties of the resulting composites are described. CH2C12 is found to be the best solvent for prepregging. The composites are shown to exhibit similar mechanical properties to 177°C cure epoxy matrix composites but to have better retention of these properties in hot/wet environments.
Tensile strength of chopped-fiber reinforced SMC composites with circular cut-outs Chaturvedi, S.K. and Keshavarz-Valian, A. SAMPE Quarterly Vol 18 No 3 (April 1987) pp 1-9 Uniaxial tensile strength tests were carried out on specimens of SMC-R50 and SMC-R65 (SMC containing 50% and 65%, respectively, of chopped glass fibres, 25.4 m m long). Both materials were found to exhibit the 'hole-size effect'. However, results for the R65 material showed a good correlation with the strength predictive models based on linear elastic
fracture mechanics and on the point stress criterion, whereas those for R50 did not. Temperature dependence of hydrothermal ageing of CSM-laminate during water immersion Phani, K.K. and Bose, N.R. Composites Science and Technology Vol29 No 2 (1987) pp 79-87 Random glass fibre (E-glass CSM)-reinforced isophthalic polyester resin specimens were stored in hot distilled water baths maintained at various temperatures. Effects of the environmental history on strength characteristics of the composites were investigated by three-point bending tests and the degradation studied by micro-observation. The study shows that the hydrothermal degradation of the laminates is a rate process for which the temperature influences only the rate constant, and the rate constant follows an Arrhenius equation. Thus, using this equation, if the activation energy of the degradation process is known, it will be possible to estimate the slreiagth at any temperature from experiments conducted at only one temperature. Thermally induced stresses and deformation in angle ply composite tubes Hyer, M.W. and Rousseau. C.Q. Journal of Composite Materials Vol 21 (May 1987) pp 454480 The effects of a uniform temperature change, from cure, on the stresses, axial expansions and thermally induced twist on four designs of angle-ply tubes made of P775/934 are investigated. Hybrid tubes using T300/934 in the off-axis layers and P775/934 in the axial layers were also studied. It was found that the tube design had only a minor influence on the stresses, axial stiffness and axial thermal expansion; instead it influenced the thermally induced twist and torsional stiffness. These proportions were also found to be dependent on the off-axis angle and the material selected.
ai atr"ac of Abstracts of Britt'sh Patents are prepared by Dr F.R. Jones, Department of Ceramics, Glasses and Polymers, Univers/ty of Shelf/e/d, UK
UK PATENTS
COMPONENTS Composite integral car body (Jinsheng, T of China) GB2177973A (4February 1987) A h a n d l a y - u p p o l y e s t e r G R P o n t o a foam mould is described. Tool handles (Fabien, RL. of UK) GB 2 186 578A (19August
1987) A unidirectional G R P sparis used as a stiffening core for a wooden handle. Billiard cue with hollow body and foamed core (Tsai, S.-K. ofTaiwan) GB 2187 646 A (16 September 1987) The cue consists of a hollow rolled FRP tube filled with a foamed core.
COMPOSITES. JANUARY 1 9 8 8
Articles of filled synthetic polymeric materials and glass bead filler therefor (Glaverbel, Belgium)GB 2 188 935,4 (14 October 1987) Coated glass bead fillers a re described. The coating must have a Tg at least 15°C lower than the m atrix to endow impact resistance to the articles.
MATERIALS Liner material (Bristol Composite materials Engineering Ltd, UK) GB 2 185 438A (22July 1987) A mineral fibre-particulate woven or non-woven paper-reinforced phenolic liner for aircraft structures is described. Honeycomb materials (H.R. Smith (Technical Developments) Ltd, UK) GB 2 188 866 A (14 October 1987) A method of manufacturing a polymeric honeycomb structure from non-reinforced or fibrereinforced advanced thermoplastic layers (eg, PES or PEEK) is claimed.
PROCESSES Pultrusion method (FiberforceLtd, UK) GB 2 186 833A (26August 1987) A strippable extruded thermoplastic coating is used to produce a pultruded profile with a smooth surface. A method of improving the oxidation resistance of graphites (The Plessey Co plc, UK)GB2187178A (3September 1987) The title claim is achieved by vacuum impregnation of an aqueous refractory precursor which forms a protective film by hydrolysis, thermal decomposition or chemical reaction. Aluminium nitrate is described. Moulding fibre reinforced articles (Advanced Composite Components Ltd, UK) GB 2 187 672 A (16 September 1987) A method of forming a conformed layer of armour onto an article using prepreg technology is described.
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