Compatibilizers for Melt Blending:  Premade Block Copolymers

Abstract

Poly(methyl methacrylate) (PMMA) was melt mixed 30:70 into polystyrene (PS) with and without symmetric P(S-b-MMA) diblock copolymers. The molecular weight of the components was varied. After 5 min of shear mixing, the PMMA was dispersed into roughly spherical, submicron particles. Particle size was measured by light scattering and transmission electron microscopy. As little as 1% copolymer led to a significant reduction in PMMA particle size, although larger amounts were needed to make the particles stable to annealing (180 °C for 15 min). The principle role of block copolymers in controlling morphology appears to be in preventing coalescence. Preventing dynamic coalescence leads to size reduction, while preventing static coalescence results in stability or compatibilization. We estimate that less than 5% of the interface needs to be covered to prevent dynamic coalescence while ∼20% is necessary to impart static stability. Mobility, critical micelle concentration, and molecular weight of the block copolymer also appear to be important. Lowering the molecular weight of the PMMA phase from 43 000 to 11 000 resulted in dramatically lower particle size (700 vs 60 nm). These variables are discussed in terms of a qualitative balance between rate of diffusion and rate of area generation during blending.

Rheological, Morphological and Mechanical Characterization of Recycled Poly (Ethylene Terephthalate) Blends and Composites

“…The compatibilized PET rec /EMA/EMA-GMA blend with 25 wt% of EMA and 5 wt% of EMA-GMA ( Figure 6) showed smaller particle size compared to its corresponding PET rec /EMA blend with 30 wt% of EMA, and the reduction in particle size was due to the presence of EMA-GMA compatibilizer. Macosko et al 31 attributed this to entropic repulsion of molecules located at the compatibilizer interface while balancing the Van der Waals forces and reducing coalescence. Huber et al 12 found a decrease in interfacial tension due to the presence of the compatibilizing agent that decreased the size of the dispersed phase, in which the coalescence probability drops to a negligible value.…”

Solvent-free preparation, characterization, and properties of SEBS–g–polycarbonate copolymers

“…[5] The first one is the addition of a graft or block copolymer. [6][7][8][9][10][11][12] To form a graft copolymer, two strategies exist, the grafting from between polymers [13][14][15][16][17][18][19][20][21] and the grafting onto, [22][23][24][25][26][27][28][29] with a polymer bearing an initiating function previously induced by ozonolysis or irradiation. [30,31] A coupling reaction through a function can also be used to generate specific functions onto a polymer chain moiety to then start a grafting from or a grafting onto.…”

Reactive compatibilization of PC/PVDF polymer blends by zinc carboxylate containing poly(methylmethacrylate) ionomers

“…As result, less graft copolymer is formed at the interface. Although this amount is large enough to stabilize the phase morphology against coalescence [33], it is too small to improve the toughness of the interface, which strongly depends on the amount of block or graft copolymer added to the blends [34].…”