Department of Materials Science, University of Patras, 26504 Rio Patras, Greece, Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vass. Constantinou Avenue, 116 35 Athens, Greece, Institut de Biologie Moleculaire et Cellulaire, UPR9021 CNRS, Immunologie et Chimie Therapeutiques, 67084 Strasbourg, France, and Dipartimento di Scienze Farmaceutiche, Universita di Trieste, Piazzale Europa 1, 34127 Trieste, Italy

Chemistry of Carbon Nanotubes

Small but strong: A review of the mechanical properties of carbon nanotube–polymer composites

Carbon nanotube–polymer composites: Chemistry, processing, mechanical and electrical properties

Chemical oxidation of multiwalled carbon nanotubes

Natural fiber reinforced polymer composites (NFPCs) provide the customers with more alternatives in the material market due to their unique advantages. Poor fiber–matrix interfacial adhesion may, however, negatively affect the physical and mechanical properties of the resulting composites due to the surface incompatibility between hydrophilic natural fibers and non-polar polymers (thermoplastics and thermosets). A variety of silanes (mostly trialkoxysilanes) have been applied as coupling agents in the NFPCs to promote interfacial adhesion and improve the properties of composites. This paper reviews the recent progress in using silane coupling agents for NFPCs, summarizes the effective silane structures from the silane family, clarifies the interaction mechanisms between natural fibers and polymer matrices, and presents the effects of silane treatments on the mechanical and outdoor performance of the resulting composites.

Silane coupling agents used for natural fiber/polymer composites: A review

Multiwalled carbon nanotubes (MWNTs) grafted with poly(methyl methacrylate) (PMMA) were synthesized by emulsion reactions and used as a reinforcement for commercial PMMA. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the applied tensile load on the composites was transferred to the PMMA-grafted MWNTs, leading to a strain failure of the MWNTs rather than an adhesive failure between the MWNTs and the matrix. Dynamic mechanical analysis (DMA) data showed that the storage modulus at 20 °C of the PMMA composite containing 20 wt.-% of the PMMA-grafted MWNTs was significantly enhanced by ∼ 29 GPa (or by ∼ 1100 %) as compared with commercial PMMA.

Efficient Load Transfer to Polymer-Grafted Multiwalled Carbon Nanotubes in Polymer Composites†

Effects of polarity and pH on the solubility of acid-treated carbon nanotubes in different media

In this work, multiwalled carbon nanotubes (MWNTs) were surface-modified and grafted with poly(L-lactide) to obtain poly(L-lactide)-grafted MWNTs (i.e. MWNTs-g-PLLA). Films of the PLLA/MWNTs-g-PLLA nanocomposites were then prepared by a solution casting method to investigate the effects of the MWNTs-g-PLLA on nonisothermal and isothermal melt-crystallizations of the PLLA matrix using DSC and TMDSC. DSC data found that MWNTs significantly enhanced the nonisothermal melt-crystallization from the melt and the cold-crystallization rates of PLLA on the subsequent heating. Temperature-modulated differential scanning calorimetry (TMDSC) analysis on the quenched PLLA nanocomposites found that, in addition to an exothermic cold-crystallization peak in the range of 80–120 °C, an exothermic peak in the range of 150–165 °C, attributed to recrystallization, appeared before the main melting peak in the total and nonreversing heat flow curves. The presence of the recrystallization peak signified the ongoing process of crystal perfection and, if any, the formation of secondary crystals during the heating scan. Double melting endotherms appeared for the isothermally melt-crystallized PLLA samples at 110 °C. TMDSC analysis found that the double lamellar thickness model, other than the melting-recrystallization model, was responsible for the double melting peaks in PLLA nanocomposites. Polarized optical microscopy images found that the nucleation rate of PLLA was enhanced by MWNTs. TMDSC analysis found that the incorporation of MWNTs caused PLLA to decrease the heat-capacity increase (namely, ΔCp) and the Cp at glass transition temperature. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1870–1881, 2007

Yeong-Tarng Shieh

Papers

Efficient Load Transfer to Polymer-Grafted Multiwalled Carbon Nanotubes in Polymer Composites†

Effects of polarity and pH on the solubility of acid-treated carbon nanotubes in different media

Effects of carbon nanotubes on crystallization and melting behavior of poly(L‐lactide) via DSC and TMDSC studies

Crystallization behavior, crystal transformation, and morphology of polypropylene/polybutene-1 blends

Significant improvements in mechanical property and water stability of chitosan by carbon nanotubes