Enhancement of crack propagation resistance in epoxy resins by introducing poly(dimethylsiloxane) particles

• Published in: Journal of materials science Vol. 34; no. 8; pp. 1775 - 1781
• Main Authors: REY, L, POISSON, N, MAAZOUZ, A, SAUTEREAU, H
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 15.04.1999; Springer Nature B.V
• Subjects: Applied sciences; Coefficient of friction; Compression tests; Crack propagation; Deformation mechanisms; Diuron; Epoxy resins; Exact sciences and technology; Fatigue failure; Fracture mechanics; Fracture surfaces; Friction resistance; Heat treating; Image analysis; Image quality; Image transmission; Linear elastic fracture mechanics; Materials science; Mechanical properties; Mechanical tests; Mixtures; Modulus of elasticity; Organic polymers; Physicochemistry of polymers; Plastic deformation; Polydimethylsiloxane; Propagation; Properties and characterization; Toughening; Twin screw extruders; Wear rate; Dimethylsiloxane polymer; Strengthening; Epoxy resin; Mechanical properties; Dispersion reinforced material; Experimental study; Crack propagation resistance; Concentration effect; Wear resistance; Tenacity; Fracture mode; Silicone elastomer; Modified material
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1023/A:1004555008043

The physical and mechanical properties of polyepoxy DGEBA /DDA/Diuron networks toughened with Poly(dimethylsiloxane) particles have been studied. Blends have been realized with two kinds of dispersion tools: a high-speed stirrer and a twin-screw extruder. The dispersion state quality is discussed using transmission spectroscopy image analysis. Poly(dimethylsiloxane) suspension in an epoxy prepolymer was used as a toughening agent. Different particle quantities were introduced: 4, 8, 15% by weight. Static mechanical tests were performed in tension and compression on these poly(dimethylsiloxane) modified materials. A slight decrease of Young's modulus and an increase in plastic deformation capacity were noticed as the volume fraction of the modifier increased. Using linear elastic fracture mechanics (LEFM), an improvement in the fracture properties (KIC, GIC) was shown. Fatigue crack growth propagation studied for the blends demonstrated that the Paris law can be used to describe the behavior of the materials. Increasing the volume fraction of the modifier leads to an improvement of fatigue crack propagation resistance. Finally a decrease in the wear rate and the friction coefficient with the increase of particle quantities has been shown (in a pin on disk configuration). Toughening mechanisms are discussed with SEM fracture surfaces.