Polypropylene layered silicate mechanical properties

Mittal, V. 2007. Polypropylene-layered silicate nanocomposites Filler matrix interactions and mechanical properties. Journal of Thermoplastic Composite Materials 20 575-599. 

Parija, S., Nayak, S. K., Verma, S. K., and Tripathy, S. S. 2004. Studies on physico-mechanical properties and thermal characteristics of polypropylene/layered silicate nanocomposites. Polymer Composites 25 646-652. 

L. Cauvin, D. Kondo, M. Brieu, N. Bhatnagar, Mechanical properties of polypropylene layered silicate nanocomposites characterization and micro-macro modelling. Polymer Testing 29 (2) (2010) 245-250. 

Mittal V (2007) Polypropylene-layered silicate nanocomposites filler matrix interactionsand mechanical properties. J Thermoplast Compos Mater 20 575-599 Moore DM, Reynolds RC (1997) X-ray diffraction and the identification and analysis of Najafi A, Kord B, Abdi A, Ranaee S (2011) The impact of the nature of nanoclay on physical and mechanical properties of polypropylene/reed flour nanocomposites. J Thermoplast Compos Okada A, Usuki A (2006) Twenty years of polymer composites. Macromol Mater Eng 291 1449-1476... 

Koo CM, Kim MJ, Choi MH, Kim SO, Chung IJ (2003) Mechanical and rheological properties of the maleated polypropylene-layered silicate nanocomposites with different morphology. J ApplPolym Sci 88(6) 1526-1535... 

Even after organic modification of the clays, polypropylene does not wet the surface of clays because it is nonpolar. It is necessary to blend in a functionalized polymer such as maleated polypropylene (PP-g-MA) that wets the modified clay surface more readily and is also miscible with the bulk polymer. Okada and coworkers were the first to produce polypropylene layered silicate nanocomposites by melt compounding the modified elay with PP-g-MA and PP. The progress made since then in preparing and characterizing polypropylene layered silicate nanocomposites is reviewed in this chapter. We discuss advances in formulations, preparation methods and characterization then proceed to effects of the dispersion state (intercalated vs. exfoliated) and of silicate loading on crystallinity, mechanical performance and other properties, and end with a summary of progress to date with these composites. All the results presented in this chapter refer to isotactic polypropylene nanocomposites with layered or smectite clays. 

Sumita M, Tsukumo Y, Miyasaka K et al (1983) Tensile yield stress of polypropylene composites filled with ultrafine particles. J Mater Sci 18 1758—1764 Thellen C, Orroth C, Froio D et al (2005) Influence of montmorillonite layered silicate on plasticized poly(l-lactide) blown films. Polymer 46 1716-11727 Uyama H, Kuwabara M, Tsujimoto T et al (2003) Green nanocomposites from renewable resources plant oil-clay hybrid materials. Chem Mater 15 2492-2494 Wang SF, Shen L, Zhang WD et al (2005a) Preparation and mechanical properties of chitosan/ carhon nanotuhes composites. Biomactomolecules 6 3067—3072... 

P. Motamedi, R. Bagheri, Investigation of the nanostructure and mechanical properties of polypropylene/polyamide 6/layered silicate ternary nanocomposites. Materials and Design 31 (4) (2010) 1776-1784. 

Lee S, Hong J-Y, Jang J (2003) The effect of graphene nanofiller on the crystallization behavior and mechanical properties of poly(vinyl alcohol). Polym Int 62 901-908 Lele A, Mackley M, Galgali G, Ramesh C (2002) In situ rheo-x-ray investigation of flow-induced orientation in layered silicate-syndiotactic polypropylene nanocomposite melt. J Rheol 46 1091-1110... 

Maiti P., Nam P. H., Okamoto M., Hasegawa N. and Usuki A., Influence of crystallization on intercalation, morphology, and mechanical properties of polypropylene/clay nanocomposites . Macromolecules, 2002, 35, 2042-2049. Galgah G., Ramesh C. and Lele A., Rheological study on the kinetics of hybrid formation in polypropylene nanocomposites , Macromolecules, 2001, 34, 852-858. Abranyi A., Szazdi L., Pukanszky Jr B., Vancso G. J. and Pukanszky B., Formation and detection of clay network structure in poly(propylene)/layered silicate nanocomposites , Macromol Rapid Commun, 2006, 27, 132—135. 

Retort is a high temperature sterilization process that is used to prolong the shelf life of military rations. Ethylene co-vinyl alcohol (EVOH) /montmorillonite layered silicate (MLS) nanocomposites were co-extruded with retort grade polypropylene (PP) into a multilayer cast fdm to determine if the addition of MLS to EVOH improved barrier, mechanical, thermal and retort properties. The PP/EVOH-MLS/PP structure showed an improvement in some properties such as water vapor transmission rate. Young s modulus, and seal strength before retort in comparison to the PP/EVOH/PP structure however, the improvement in properties was lost after the retort process. 

---