Engineering polymer blends future perspective

Specific blends, which could offer an interesting combination of properties with proper com-patibilization, include PPS/PSE, PEl/PPS, PA/PSE, PA/PEI, and PC/PPS. Patent activity has been noted for most of these blend combinations as well as other selected blends involving engineering polymers as noted in Table 17.3. A number of recent patent and published papers have discussed blends of engineering polymers with various specialty polymers including high temperature polymers, liquid crystalline polymers (LCP s), conductive polymers, and as matrix materials for molecular composites. These will be discussed in the following sections. 

In the future, prospects for combining engineering polymers with the lower cost commodity polymers should lead to unique cost/performance systems. Potential combinations might include PC/PP, polyester (PBT, PET)/PP and POM/PP or HOPE. Newer commercial polyamides (PA-46 Amodel (Amoco) aliphatic/aromatic polyamide) should also be off interest in new blend combinations. An example of this involves Amodel/ PPS blends as noted by Chen and Sinclair [1997]. Although the rate of introduction of new engineering polymers has decreased, new additions will be continued to be expected and thus new blend combinations will also be offered. 

PPS/PSE blends could offer an interesting compromise in properties with PPS offering chemical resistance and polysulfone offering toughness and excellent thermal stability. PA blends with PSE and PEI could offer advantages in chemical resistance offered by the PA and stiffness at higher temperatures and dimensional stability offered by the engineering polymers. Miscibility of PEI and 

PET has been noted by several studies [Chen., 1995 Jang and Sim, 1997 and Hwang et al., 

Crystallization kinetics [Hwang et al., 1997] and spectroscopic studies [Jang and Sim, 1997] have been reported showing the expected decrease in crystallization rate of PET with added PEI. This blend offers a balance of improved solvent resistance and melt flow with PET addition and higher heat distortion temperature with PEI addition. 

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