Power compatibilization

Aijunan, P. Technological Compatibilization of Dissimilar Elastomer Blends Part 1. Neoprene and Ethylene o-Propylene Rubber Blends for Power Transmission Belt Application. Rubber Division, Proceedings of the American Chemical Society, Nashville, TN, Sept. 29-Oct. 2, 1998, Paper No. 52, 1-28. 

Well-dispersed and long-term stable carbon nanotubes/polyol dispersions can also be prepared by a mechanochemical approach with the aid of a dispersing agent (Tang and Xu, 1999). Good dispersion of CNTs in polymer matrix can be achieved by means of high-power dispersion, compatibilizer, polymer-assisted blending, and surfactants (Cochet et al., 2001). 

Macromonomers afford a powerful means of designing a vast variety of well-defined graft copolymers. These species are particularly useful in the field of polymer blends as compatibilizers and/or stabilizers (surfactants). When macromonomer itself is an amphiphilic polymer, then its polymerization in water usually occurs rapidly as a result of organization into micelles. In copolymerizations, important factors for macromonomer reactivity are the thermodynamic repulsion or incompatibility between the macromonomer and the trunk polymer and its partitioning between the continuous phase and the polymer particles [4,5]. 

In the case of a binary A/B blends, Helfand and his co-authors provided the basic relations and the theoretical guidance to the properties of the interface, as well as to their modification by incorporation of a compatibilizer. The theory is based on strong, hmiting assumptions (e.g., infinitely long macromolecules), thus one should not expect a quantitative agreement with experimental data. However, the theoretically predictions offer a powerful guidance for the best compatibihzation strategies. 

It is to be hoped that fumre work on Reactive Compatibilization will combine the excellent materials science that has been done to date with additional considerations of the chemical processes occurring. Such knowledge of the chemistry, coupled to fluid mechanics and morphology development models, would provide a powerful tool for optimization of known and invention of new Reactive Compatibilization processes to prepare commercially valuable polymer blends. 

Functionahzation of styrene polymers and their blends have been treated in several studies (3) dealing with the preparation of compatibilizers for blends containing engineering thermoplastics. It is worthy to note that in presence of peroxides (DCP), polystyrene (PS) suffers preferable degradation in the melt (64,65). The grafting power of MAH and its derivatives (diethyl maleate, dimethyl maleate) is much lower to PS than to PO, and this fact—in Xue et al. s opinion (64)—indicates a low reactivity of benzyl macroradicals. 

The major field of application of functionalized PO blends and functionalized homo-polyolefins is compatibilization of blends of condensation polymers. The use of functionalized PO blends, in place of homopolyolefins, has a number of advantages. First, by ratio variation of PO in the blend, it is possible to change the degree of microheterogeneity of the final product this fact is of importance for impact strength (67). Second, the selective nature of grafting can be useful in controlling the functionalization power of one or another component in PO blends. 

PA/PP compatibilized blends, with PA being the matrix phase, have excellent impact resistance making them suitable for automotive, garden and power tool applications. 

Li et al. [101] introduced high-power ultrasound into PS/EPDM (80/20) blend melts during extrusion. The structure and properties of sonicated PS/EPDM blends were investigated by measuring the mechanical and rheological properties and morphology. In general, when a compatibilizer was added to a completely incompatible polymer blend, the disperse phase tended to become spherical and... 

The study of the ultrasonic treatment of polyester/LCP blends is of particular interest as the continuous compatibilization of these blends is of great commercial value [9]. In this article, we study the effects of high power ultrasound on the rheology, morphology, and mechanical properties of pure PET, LCP and their blends. 

Over the past decade extensive work has been done to develop a novel extrusion process with the aid of high power ultrasound [18-22], A number of studies on the effect of ultrasound on polymers have been published and reported in various review articles and books. It was shown that ultrasonic oscillations can breakdown the 3-D network in vulcanized rubber within seconds. Ultrasound was found to improve the compatibilization of immiscible plastic blends, plastics/rubber and rubber/rubber blends during extrusion process [23]. In recent years, use of ultrasound to disperse nanofdler in a polymer matrix is gaining attention. Ultrasound helps in rapid exfoliation and intercalation of nano-clay in a polymer matrix [24]. 

---