GREEN NANOCOMPOSITES BASED ON ALIPHATIC POLYESTERS AND MOROCCAN CLAY 

Project leaders

Simona Bronco, Mustapha Raihane

Agreement

MAROCCO - CNRST - Centre National pour la Recherche Scientifique et Technique

Call

CNR/CNRST 2012-2013

Department

Materials and Devices

Thematic area

Physical sciences and technologies of matter

Status of the project

New

Research proposal

This proposal is supported by IPCF-CNR UOS of Pisa, and Bioorganic and Macromolecular Chemistry laboratory belonging to Cadi Ayyad University of Marrakech. The main objective is to develop an integrated research on advanced bionanocomposite materials of diverse nature from abundant, cheap and of little environmental impact natural resources. The novelty of this research consists in the use of new type of fillers conveniently modified to ensure in situ metal catalyzed polycondensations (e.g. of dicarboxylic acids and aliphatic diols), resulting in controlled nanostructured hybrid/nanocomposite materials with highly improved properties (barrier properties, heat and UV resistance, dimensional stability, mechanical strength). Additional polymer matrices proposed by IPCF-CNR based on bio-related polyesters and water-based synthetic polymer dispersions will also be considered. Further to that, the research will include an investigation of the interfacial interactions between the polymer matrices and the biofiller. It is foreseen that the resulting bionanocomposites will be evaluated in cooperation with a SME such as Société Ghassoul from Morocco for potential applications and even in preliminary test for scaling up production. The complementary and synergic background of the research teams is one of the strongest points of the proposal. Moreover, the research group of Prof. Valter Castelvetro, an Associate of IPCF-CNR and of the staff member of the Department of Chemistry and Industrial Chemistry of the University of Pisa, have collaborated in the past with Professor M. RAIHANE [Intergovernmental Scientific and Technological Collaboration Program between Morocco and Italy (2004-2008) and International Academic Cooperation Support Action Program between Cadi Ayyad University and the University of Pisa (2009-2010)], and the further development of the collaboration among the two research groups is one of the benefits expected from this project between Pisa and Marrakech.
The methodology to develop the abovementioned work-plan is firstly addressed to the selection of the starting silicates. This task will be in charge of Prof. B. Rhouta from the Moroccan group with large experience in Morocco clay deposits as well as GHASSOUL experts. Conventional methods will be applied for purification and extraction of the clay fraction from the raw minerals with special emphasis on stevensite of Rhassoul. The clays will be characterized by diverse instrumental techniques that include mineralogical and chemical analyses, X-ray diffraction (XRD), thermal analysis (TG-DTA, DSC), textural analysis, FTIR and RMN spectroscopies, and TEM. Secondly it will be carried out the modification of clay surface by treatments with different surfactant agents, mainly of cationic nature, with the aim to transform the hydrophilic clays into organophillic organoclays. These materials will be analyzed and their synthesis optimized with the help of different experimental techniques such as those above mentioned for the characterization of the starting clays. This task will be in charge of both Moroccan and Italian Team. Aliphatic polyesters such as poly(butylene succinate) PBS and poly(butylene apidate) PBA bionanocomposites will be prepared by in situ polycondensation of 1,4-butanediol and diacid carboxylic (succinic acid or adipic acid) or their corresponding dimethy esters. Polycodensation will be catalyzed by Bismuth and titane salts previously inserted into the interlayer space between tha lamellas of the clay. The ckay will be also disperded in commercial PBS, PBA e PCL by a process in the melt as a comparison by the IPCF-CNR unit . To obtained nanostructed composites, different parameters will be controlled : ratio of Monomers in the feed, ratio [monomers]/[Catalyst], temperature, time of polymerization, % of clay (unmodified and modified clay). Water based polymers dispersions and their nanocomposites by a previous functionalization of the clay  will be also prepared by IPCF-CNR of Pisa. In Pisa all the chemical-physial characterization of the nanocomposites will be carried out in order to establish the relationships between  nanostructure/properties. The experience of the Moroccan and Italian Teams in the synthesis of bioplastics and their nanocomposites will be an opportinity to put their efforts and knowledge together. Characterization of bionanocomposites will be carried out by the physico-chemical techniques available at Marrakech and Pisa listed below:
* Morphological and structural characterization: solid state nuclear magnetic resonance, dielectric spectroscopy, X-ray diffraction, optical and scanning electron microscopy, atomic force microscopy, raman and infrared spectroscopy.
* Physical characterization: rheology, mechanical properties, thermo-gravimetric analysis, differential scanning calorimetry and barriers properties.
Those bionanocomposites successfully developed at lab scale will be intended to be produced at lager scale. Preliminary test for scaling up processes will be carried out with the help of "la Société Ghassoul et ses dérivés", from Morocco.
Finally, concerning the project managment and in particular the coordination ot the common activities and tasks distribution, specific meetings will be regularly appointed also in web-conferences in view to exchange information and to plan the work between individual groups involved in common tasks.
The project submitted within the framework of this call proposal between Morocco-Italy falls under continuity and will establish the basis for long-term research cooperation in addition to the development of new green nanocomposites materials. The experience of the Moroccan and Italian Teams in the synthesis of bioplastics and their nancomposites will be an opportunity to put their efforts and knowledge together in order to achieve the objects of this project. The role of each partner is described below.
LCBM - Marrakech (Morocco)          * Extraction , purification and organomodification of Moroccan nanoclay;* Elaboration of nancomposites bazed on Aliphatic polyesters and Rhassoul clay;* Characterization of the obtained nanocomposites;* Study of their physical properties
IPCF-CNR UOS Pisa (Italy)                  * Elaboration of Water based synthetic polymers dispersions;* Preparation dispersed polymers and biofiller; nanocomposites;* Establishment of relationship nanostructure/properties.
 In particular: * The project will link Italian Team through effective partnership with Moroccan Team which significantly enhances research capacity of the partners by supervising PhD, Master, engineers students, * The project will focus on research and education in the area of polymer materials design. This area can promote global economic development, * This collaboration project could be a good opportunity for future exchange of researchers and students between the partners. Sharing the research and educational experiences will demonstrate the value added by the international collaboration, * workshops and seminars will be organized, *joint presentations and papers communicating results of the project in international journal will be prepared, *a critical mass of Scientifics to encourage the internationalization of research institutions will be created;  * The valuing of the clay of Morocco * The use of some of this clay as nanofiller and others from non-toxic catalysts under standard conditions (without the use of inert nitrogen or argon) allow the preparation of innovative nanomaterials and respectful of the environment.

Research goals

2-Objective of the projet
The main objective of the project is to investigate the development of a new type of nanostructured materials, prepared from natural, ecofriendly and cheap natural resources as mineral clays and bio-related polyesters or water-based synthetic polymer dispersions. The mineral clay (Rhassoul) is abundant in Morocco, located at south -eastern border of the basin of Missour and hystorically used by women in Middle East for beautiful hair and skin of the body. This material has an high capability to swell in the presence of water and in this form to adsorb fat molecules. The involved nanoclays are of smectites clays-type. Bio-related polyesters such as poly(butylene succinate) PBS and  poly(butylene apidate) PBA, poly-caprolactone PCL and water-based synthetic polymer dispersions will be used as polymer matrices.
In the case of biodegradable polyesters, disaggregation of these nanoclay particles is achieved in two steps. The first one is the intercalation to increase the interlayer distance by using the clay (or a conveniently organo-modified clay) as support for an in-situ polycondensation of diols with aliphatic dicarboxylic (ADAs) or dimethyl ester of ADAs whereby a metal catalyst (Bismuth and Titanium salts) is inserted within the layers. The second step is the exfoliation of the modified clays allow the dispersion of the individual lamellae in the polymer matrix. Dispersione of the clay in commercial polymer matrices is also investigated by process in the molten state as comparative tests.
In the case of water-based synthetic polymer dispersion, the clay is firstly chemically functionalized. After that the clay particles are dispersed into water and engaged further in a free radical emulsion polymerization process to produce colloidal nanocomposites with covalent grafting between the exfoliated clay sheets and the polymeric matrix.
The nanocomposites are fully characterized.

Last update: 08/10/2024