Foams with enhanced ductility and impact behavior based on polypropylene composites

Producción CientíficaIn this work, formulations based on composites of a linear polypropylene (L-PP), a long-chain branched polypropylene (LCB-PP), a polypropylene–graft–maleic anhydride (PP-MA), a styrene-ethylene-butylene-styrene copolymer (SEBS), glass fibers (GF), and halloysite nanotubes (HNT-QM) have been foamed by using the improved compression molding route (ICM), obtaining relative densities of about 0.62. The combination of the inclusion of elastomer and rigid phases with the use of the LCB-PP led to foams with a better cellular structure, an improved ductility, and considerable values of the elastic modulus. Consequently, the produced foams presented simultaneously an excellent impact performance and a high stiffness with respect to their corresponding solid counterparts.Unión Europea (Evolution project under grant 314744)Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (project RTI2018-098749-B-I00)Junta de Castilla y Leon (project VA275P18

Morphological and Tribological Properties of PMMA/Halloysite Nanocomposites

From an environmental and cost-effective perspective, a number of research challenges can be found for electronics, household, but especially in the automotive polymer parts industry. Reducing synthesis steps, parts coating and painting, or other solvent-assisted processes, have been identified as major constrains for the existing technologies. Therefore, simple polymer processing routes (mixing, extrusion, injection moulding) were used for obtaining PMMA/HNT nanocomposites. By these techniques, an automotive-grade polymethylmethacrylate (PMMA) was modified with halloysite nanotubes (HNT) and an eco-friendly additive N,N′-ethylenebis(stearamide) (EBS) to improve nanomechanical properties involved in scratch resistance, mechanical properties (balance between tensile strength and impact resistance) without diminishing other properties. The relationship between morphological/structural (XRD, TEM, FTIR) and tribological (friction) properties of PMMA nanocomposites were investigated. A synergistic effect was found between HNT and EBS in the PMMA matrix. The synergy was attained by the phase distribution resulted from the selective interaction between partners and favourable processing conditions. Modification of HNT with EBS improved the dispersion of nanoparticles in the polymer matrix by increasing their interfacial compatibility through hydrogen bonding established by amide groups with aluminol groups. The increased interfacial adhesion further improved the nanocomposite scratch resistance. The PMMA/HNT-EBS nanocomposite had a lower coefficient of friction and lower scratch penetration depth than PMMA/HNT nanocomposite.Financial support by the EU Commission through Project H2020-686165-IZADINANO2INDUSTRY is gratefully acknowledged

The Effect of SEBS/Halloysite Masterbatch Obtained in Different Extrusion Conditions on the Properties of Hybrid Polypropylene/Glass Fiber Composites for Auto Parts

Masterbatches from a linear poly[styrene-b-(ethylene-co-butylene)-b-styrene] (SEBS) and halloysite nanotubes (HNT-QM) were obtained in different conditions of temperature and shear using two co-rotating twin-screw extruders. The influence of screw configuration and melt processing conditions on the morpho-structural, thermal and mechanical properties of masterbatches at macro and nanoscale was studied. A good dispersion of halloysite nanotubes and better thermal stability and tensile and nanomechanical properties were obtained at a lower temperature profile and higher screw speed. The effect of masterbatches, the best and worst alternatives, on the properties of a polypropylene (PP)–glass fiber (GF) composite was also evaluated. Double hardness, tensile strength and modulus and four times higher impact strength were obtained for PP/GF composites containing masterbatches compared to pristine PP. However, the masterbatch with the best properties led further to enhanced mechanical properties of the PP/GF composite. A clear difference between the effects of the two masterbatches was obtained by nanoindentation and nanoscratch tests. These analyses proved to be useful for the design of polymer composites for automotive parts, such as bumpers or door panels. This study demonstrated that setting-up the correct processing conditions is very important to obtain the desired properties for automotive applications

A Concrete and Viable Example of Multimaterial Body: The Evolution Project Main Outcomes

Funded by the EC FP7 Programme, EVolution project demonstrated that it is possible to consistently reduce the vehicle weight through the wide use of new materials and process technologies, mainly by developing a multi-material Body-in-White. This paper focuses on three of the five structural body demonstrators, the main objective of the framework, strongly hybridized with aluminum and thermoplastic composite materials, specifically developed and manufactured through innovative technologies. Directing in particular the analysis on medium production volumes (> 30,000 units/year), the industrial viability is evaluated in terms of TAKT time, lightweighting costs, weight reduction and structural performances achieved.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 314744

Evolution FP7 funded project: body structure design strategies using new composite and aluminium materials and enabled technologies

Based on Pininfarina Nido EV concept, EVolution aims to reduce the vehicle weight through new materials and process technologies, focused on five demonstrators: underbody, front crossbeam, mechanical subframe, shotgun system and door. This paper refers to body structure design strategies using new composite, Al materials and enabled technologies, focusing in particular on demonstrators design and manufacturing. The new front crossbeam geometry of the front shell is adapted starting from the Nanotough design, while the rear shell is specific for EVolution. The subframe demonstrator is redesigned to fulfil mechanical requirements of the part and manufacturing feasibility either. The EVolution door concept consists of two semistructural composite skins including a structural Al frame. The underbody is conceived through an integrated approach, optimising each element for its function. The shotgun component is designed to link parts obtained with different manufacturing technologies and several aluminium alloys in one single component: the structural node demonstrator.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 314744