Toughness blended polymers

Physical or chemical modification methods have been employed to increase the toughness of polymer materials. The chemical modifications include random copolymerization, block copolymerization, grafting, etc. the physical ones include blending, reinforcing, filling, interpenetrating networks etc. [24-26]. 

Wu S (1990) Chain structure, phase morphology, and toughness relationships in polymers and blends. Polym Eng Sci 27 335-43. 

Gen Gensler, R., BegueUn, P., Plummer, C. J. G., Kausch, H.-H., Mtinstedt, H. Tensile behaviour and fracture toughness of poly (ether ether ketone)/poly (ether imide) blends. Polym. Bull. 37... 

Gebizlioglu, O. S., Argon, A. S., and Cohen, R. E. (1985) Craze plasticity and toughness of particulate block copol5mer blends, Polymer, 26, 529-542. 

Blending polymer is similar to alloying metal, to obtain the complementary advantages of two materials. For example, polystyrene (PS) appears hard and brittle, while polybutadiene (PB) appears soft and tough. By adding amphiphilic... 

Armat, R. and Moet, A. 1993. Morphological origin of toughness in p>olyethylene-nylon-6 blends. Polymer 34 977-985. 

The results presented in Fig. 11.21 are very meaningful as they clarify some of the key issues concerning the contribution of void formation to toughness in polymer blends. It appears that the cavitation is extremely important in notched specimens because it allows the blend to yield under plane-strain conditions at stiU moderate stresses due to increased sensitivity to the mean stress. It implies that this modification of yielding does not result from eliminating geometrical constraints and converting a state of plane-strain to plane-stress state, as it has been frequently postulated in the past (Bucknall and Paul 2009). 

Average particle diameter of the mbber, D, and its volume fraction, < ), are among the most essential factors affecting the toughness of polymer blends. The concentration of the mbber must be well balanced in order to obtain material with... 

Polymer blends are often used in adhesive formulations where properties associated with rigid polymers (high temperature resistance, chemical resistance, etc.) must be obtained along with properties associated with tough, elastic polymers (impact strength, high peel strength, etc.). Examples of these adhesive systems are nylon-epoxy, phenolic-nitrile, epoxy-polysulfide, epoxy-nitrile, and epoxyurethane. 

Sederel, L.C., Mooney, J. and Weese, R.H., Super Tough Blends based on LV Nylon and an Acrylic Core/Shell Modifier, Proceedings of the European Symposium on Polymer Blends, May 25-27, 1987, Strasbourg (France). 

The effect of orientation hardening of matrix polymers on the toughness of polymer blends was examined by Ishikawa et.al. (Ishikawa et al., 1996). Both PMMA and PVC with different characteristics of orientation hardening were used as matrix polymers and a silicon/acrylic composite rubber graft copolymer was used as the... 

To the vinylester resins, thixotropic agents are added, for example silica fume (silicon dioxide in microspheres, which is a by-product of the glass industry), to obtain a behaviour adequate to their use also in open moulds. In addition, to improve their toughness, CTBN polymers (carboxyl-terminated copolymers of butadiene and acrylonitrile) are widely employed as reactive modifiers. This occurs since the CTBN-modified vinylester oligomers act as compatibilizers for blending additional butadiene copolymer (Burchill and Pearce, 1996). 

Different properties of NR-based materials can be obtained through blends with biopolymers. The rubber particles behave as stress concentrators, enhancing the fracture energy absorption of brittle polymers and ultimately resulting in a material with improved toughness. In order to impart toughness to polymers, the following criteria must be met ... 

K. S. Anderson, M. A. Hillmyer, The influence of block copolymer microstructure on the toughness of com-patibilized polylactide/polyethylene blends. Polymer 2004, 45, 8809-8823. 

R. Gensler, Ph. Biiguelin, C. J. G. Plummer, H.-H. Kausch, and H. Miinstedt. "Tensile behaviour and fracture toughness of polyfether ether ketone)/ poly(ether imide) blends." Polymer Bulletin, pp. 111-118,1996. 

PPO is a tough rigid polymer with good dimensional stability when subjected to high temperatures and humidities. However, because it is reputedly difficult to process it may be blended to facilitate injection moulding. It is sometimes seen as a substiute for metal diecastings. 

Anderson, K.S., Hillmyer, M.A., 2004. The influence of block copolymer microstmcture on the toughness of compatibilized polylac-tide/polyethylene blends. Polymer 45, 8809—8823. 

Margolina, A. and Wu, S. (1988) Percolation model for brittle-tough transition in nylon/rubber blends. Polymer, 29 (12), 2170-2173. 

Afrifah KA, Matuana LM. Fracture toughness of poly(lactic acid)/ethylene acrylate copolymer/wood-flour composite ternary blends. Polym Int 2013 62(7) 1053-8. 

Kinloch AJ, Lee SH, Taylor AC. Improving the fracture toughness and the cyclic-fatigue resistance of epoxypolymer blends. Polymer 2014 55 6325-34. 

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