Challenges in blending polymers

The degradability and stabilization of HTPBs was discussed in Sections 2.6 and 2.7. Now, the influence of one macromolecular blend component on another is of interest. Evidently, in totally immiscible blends the inter-species 

Most of the blends listed in Table 2.7 were prepared using commercial polymers or blends thus the results also contain the effects of industrial additives. Furthermore, blend compounding for specific morphology and performance affects blend degradability by consumption of stabilizer, chain scission, addition or formation of compatibifizers, etc. Thus, variability of the degradative behavior for the same polymer-l/polymer-2 mixture is to be expected. 

There are thousands of chemical species used as additives, namely antioxidants, metal deactivators, flame retardants, colorants, plasticizers, impact modifiers, lubricants, fungicides, bio-stabilizers, nucleating agents, antistatic agents, crosslinkers, etc. In addition, there are contaminants left after polymerization, compounding or foaming processes. Ideally, the additives should be miscible with the polymer they are supposed to reinforce, protect or color. However, thermodynamics requires that the low molecular 

1988 PC/PBT Embrittlement caused by MW reduction and PBT crystallization transreaction not observed Aged 42 days at 130°C 162 

1998 PPEK/LCP LCP lowers the degradation Tof poly(phenolphthalein-ether-ether ketone) (PPEK or PEK-C) Immiscible blends TGA up to 600°C 165 

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