Cell morphology and mechanical properties of microcellular mucell® injection molded polyetherimide and polyetherimide/fillers composite foams

Microcellular polyetherimide (PEI) foams were prepared by microcellular injection molding using supercritical nitrogen (SC-N2) as foaming agent. The effects of four different processing parameters including shot size, injection speed, SC-N2 content, and mold temperature on cell morphology and material properties were studied. Meanwhile, multiwalled carbon nanotube (MWCNT), nano-montmorillonoid (NMMT), and talcum powder (Talc) were introduced into PEI matrix as heterogeneous nucleation agents in order to further improve the cell morphology and mechanical properties of microcellular PEI foams. The results showed that the processing parameters had great influence on cell morphology. The lowest cell size can reach to 18.2 μm by optimizing the parameters of microcellular injection molding. Moreover, MWCNT can remarkably improve the cell morphology of microcellular PEI foams. It was worth mentioning that when the MWCNT content was 1 wt %, the microcellular PEI/MWCNT foams displayed optimum mechanical properties and the cell size decreased by 28.3% compared with microcellular PEI foams prepared by the same processing parameters. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4171–4181, 2013

[1]  N. Suh,et al.  A process for making microcellular thermoplastic parts , 1990 .

[2]  Karl A. Seeler,et al.  Tension-Tension Fatigue of Microcellular Polycarbonate: Initial Results , 1993 .

[3]  J. Takagi,et al.  Nanocellular foams—cell structure difference between immiscible and miscible PEEK/PEI polymer blends , 2010 .

[4]  Shengyu Feng,et al.  Thermal conductivity of silicone rubber filled with ZnO , 2007 .

[5]  S. Yamasaki,et al.  Polyethylene ionomer-based nano-composite foams prepared by a batch process and MuCell® injection molding , 2010 .

[6]  W. C. Tjiu,et al.  Morphology, thermal, and rheological behavior of nylon 11/multi‐walled carbon nanotube nanocomposites prepared by melt compounding , 2009 .

[7]  J. Yeh,et al.  Effect of organoclay and preparation methods on the mechanical/thermal properties of microcellular injection molded polyamide 6-clay nanocomposites☆ , 2011 .

[8]  J. D. Ford,et al.  Thermal conductivities of powder‐filled epoxy resins , 1993 .

[9]  L. Turng,et al.  Microcellular injection-molding of polylactide with chain-extender , 2009 .

[10]  L. Turng,et al.  Study of Shrinkage and Warpage in Microcellular Co-Injection Molding , 2006 .

[11]  Chul B. Park,et al.  An extrusion system for the processing of microcellular polymer sheets: Shaping and cell growth control , 1996 .

[12]  Chul B. Park,et al.  Processing and cell morphology relationships for microcellular foamed PVC/wood-fiber composites , 1997 .

[13]  Z. Ishak,et al.  Comparison of the mechanical properties and interfacial interactions between talc, kaolin, and calcium carbonate filled polypropylene composites , 2004 .

[14]  Matthias Wessling,et al.  Bicontinuous Nanoporous Polymers by Carbon Dioxide Foaming , 2001 .

[15]  L. Schadler,et al.  Influence of nanoparticle surface chemistry and size on supercritical carbon dioxide processed nanocomposite foam morphology , 2010 .

[16]  N. Suh.  Impact of Microcellular plastics on industrial practice and academic research , 2003 .

[17]  J. Yeh,et al.  Effect of clay and compatibilizer on the mechanical/thermal properties of microcellular injection molded low density polyethylene nanocomposites☆ , 2009 .

[18]  L. Turng,et al.  Study of injection molded microcellular polyamide-6 nanocomposites , 2004 .

[19]  D. Chung,et al.  Thermally conducting aluminum nitride polymer-matrix composites , 2001 .

[20]  Vipin Kumar,et al.  Microcellular and nanocellular solid-state polyetherimide (PEI) foams using sub-critical carbon dioxide II. Tensile and impact properties , 2011 .

[21]  Wei Gao,et al.  Highly thermally conductive room-temperature-vulcanized silicone rubber and silicone grease , 2003 .

[22]  Chul B. Park,et al.  A microcellular processing study of poly(ethylene terephthalate) in the amorphous and semicrystalline states. Part I: Microcell nucleation , 1996 .

[23]  Chul B. Park,et al.  A microcellular processing study of poly(ethylene terephthalate) in the amorphous and semicrystalline states. Part II: Cell growth and process design , 1996 .

[24]  Jungjoo Lee,et al.  A novel method for improving the surface quality of microcellular injection molded parts , 2011 .

[25]  J. Velasco,et al.  Broad-band electrical conductivity of carbon nanofibre-reinforced polypropylene foams , 2011 .

[26]  Yong-Seog Kim,et al.  Thermally conductive EMC (epoxy molding compound) for microelectronic encapsulation , 1999 .

[27]  Vipin Kumar,et al.  Microcellular and nanocellular solid-state polyetherimide (PEI) foams using sub-critical carbon dioxide I. Processing and structure , 2009 .

[28]  T. Chong,et al.  Study on the Accuracy of Injection Molded Plastic Gear with the Assistance of Supercritical Fluid and a Pressurized Mold , 2007 .

[29]  J. Yeh,et al.  Effect of dispersion capability of organoclay on cellular structure and physical properties of PMMA/clay nanocomposite foams , 2009 .

[30]  Andrzej K. Bledzki,et al.  Injection moulded microcellular wood fibre-polypropylene composites , 2006 .

[31]  Mingjun Yuan,et al.  Microstructure and mechanical properties of microcellular injection molded polyamide-6 nanocomposites , 2005 .