Effect of extruder type on the properties and morphology of reactive blends based on polyamides

Abstract

The morphology and mechanical properties of polyamide-based blends prepared in single and corotating twin-screw extruders were compared using transmission electron microscopy (TEM) techniques. Reactive polyamide blends with SEBS-g-MA ( a maleated styrenic triblock copolymer with ethylene-butylene midblocks) , EPR-g-MA ( a maleated ethylene/ propylene rubber), and ABS were selected for the purpose of this investigation. For blends of SEBS-g-MA with difunctional (nylon x,y) polyamides (e.g., nylon 6,6; nylon 12,12), the twin-screw extruder was more effective in producing a finer dispersion of the rubber phase, which resulted in a significant lowering of the ductile-brittle transition temperature in case of the nylon 6,6 blend. On the other hand, blends of SEBS-g-MA with the monofunctional nylon 6 material led to rubber particles that were too small for toughening for both extruder types employed in this work. For nylon 6/EPR-g-MA blends, the singlescrew extruder led to blends with excellent low-temperature impact properties for both single-step and masterbatch mixing techniques, whereas nylon 6 /EPR-g-MA blends prepared in a single-step operation in the twin-screw extruder were brittle under ambient conditions. For difunctional polyamide blends with ABS (compatibilized with an imidized acrylic polymer), the morphology and mechanical properties were found to be independent of the extruder type employed for processing.

Toughening PA1010 with a functionalized saturated polyolefin elastomer

“…The rather important ones include EPDM and SEBE. [11][12][13][14][15] Before blending, elastomers were often grafted with maleic anhydride, acrylic acid, or glycidyl methacrylate monomers 16 -18 to introduce active groups. Although functionalized EPDM and SEBS modifying nylon have achieved great success, the unsaturated double bond in EPDM and SEBS molecular chains could lower the aging property of their blends.…”

Compatibilização de blendas de poliamida 6/ABS usando os copolímeros acrílicos reativos MMA-GMA e MMA-MA. Parte 2: Comportamento termomecânico e morfológico das blendas

“…O ABS é um termoplástico, de menor viscosidade que um elastômero e muito utilizado devido à sua excelente tenacidade e baixo custo. A incorporação do copolímero ABS pode melhorar a resistência ao impacto sob entalhe da PA6, pois sua fase elastomérica, à base de polibutadieno (PB), apresenta um enorme potencial para aumentar a tenacidade da mistura final, bem como, diminuir a elevada absorção de umidade da PA [3][4][5][6][7][8][9][10][11] . Entretanto, como essa mistura é imiscível e incompatível, faz-se necessário o desenvolvimento de compatibilizantes capazes de reagir com os grupos terminais da PA6 e que sejam miscíveis com a fase estireno-acrilonitrila (SAN) do copolímero ABS, na interface PA6-SAN [2,5,12,13] .…”

Reactive Compatibilization of Polymer Blends

“…however, by use of the more intensive shearing in a fully intermeshing, co-rotating, twin screw extruder, these particles can be broken down to an optimal size for effective toughening (24).…”

“…During the course of this project, we abandoned SMA 25 in favor of examination of a unique series of imidized acrylic polymers formed by reacting poly(methyl methacrylate) with methyl amine (13,14,(22)(23)(24)(26)(27)(28). These polymers contain small amounts of anhydride and acid units in addition to the glutarimide structure and residual methyl methacrylate units.…”

“…This material was found to be a very effective compatibilizing agent for nylon 6/ABS blends (13,14,(23)(24)(25)(26)(27). A key element in the fundamental studies done on this system involved developing effective transmission electron microscopy techniques for characterizing blend morphology.…”