Polymer Additives and Blends

CRB30503Polymer Additives and Blends

PPE/SAN BlendBy:Muhammad Taufiq Bin Mohd Nasir (55205113686)Wan Muhammad Aiman Bin Alias (55202113691)Mohd Arifin Bin Sakirun (55202113702)

PPEProperties:ToughFlame-retardingHigh heat distortion temperaturepoly(2,6-dimethyl-1,4-phenylene ether)

Chemical structureSANProperties:Chemical resistantHigh stiffnessStress cracking resistantLow costpoly(styrene-co-acrylonitrile)Chemical structure

PPE/SAN BLEND4

In the C-co-D type compatibilizer, both segments are different with the components of the blend, A and B, but both C and D are miscible with A and B respectively5Copolymer PS-b-PMMA

One approach to compatibilize non-compatible polymers is to include in the blend of a block copolymer which contain one chain segment derived from monomers compatible with one blend polymer and another chain segment derived from monomers compatible with the other blend polymer.6Morphology of PPE/SAN

Starting at a PPE content of 40 wt%, the PPE phase does not appear fully dispersed, but already shows some degree of continuity. While increasing the PPE content up to 50-60 wt%, the continuity increases further. However, even at the 60 wt%, the co-continuity of the blend is not fully approached and SAN still forms the matrix phase. According to the theoretical considerations and the morphological observations, a PPE matrix can be achieved at elevated contents of the high-viscous PPE on the one hand (approx. 70 wt%).7

Morphology of compatibilized PPE/SANTEMs of PPE/SAN blends compatibilized by PS-b-PMMA (PPE dark, SAN - bright) The viscosity of PPE is significantly higherHowever, up to PPE contents of 60 wt%, meltprocessed PPE/SAN blends show a more continuous SAN phase so far, while the PPE appears to be rather dispersed. Thus, the blend reveals rather poor thermomechanical properties. In order to overcome this limitation, the formation of cocontinuous structures appears desirable.

9Thermal degradation of PPE and SANThermal stability of compatibilizer will degrade and decomposeFormation of Co-continouos phaseFormation of Co-continouos phaseSelection of lower molecular weight PPE reduces the viscosityReduction of the chain length of PPE affects the materials performanceTailoring of the viscosity ratio: addition of a third, low-viscous component which shows miscibility with PPE, but immiscibility with SANPolystyrene (PS) can be regarded as material of choice, as it shows miscibility with PPE

It therefore appears more advantageous to reduce the viscosity of PPE. The selection of lower molecular weight PPE could help to reduce the viscosity; however, a significant reduction of the chain length of PPE also detrimentally affects the materials performance, particularly regarding the toughness and the chemical resistance. Tailoring of the viscosity ratio by the addition of a third, low-viscous component which shows miscibility with PPE, but immiscibility with SAN therefore appears to be more promising. For this purpose, polystyrene (PS) can be regarded as material of choice, as it shows miscibility with PPE over the complete compositional and temperature range.11

Morphology of (PPE/PS)/SANTEM of (PPE/PS)/SAN (30/30)/40. Black indicates PPE/PS phase, white indicates SAN phase.

CONCLUSION

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REFERENCESLler, A., & Schmidt, H. (2010). Thermal Diffusion in Polymer Blends: Criticallity and Pattern Formation. In Complex Macromolecular Systems I (p. 220). Berlin, Heidelberg: Springer-Verlag Berlin Heidelberg.