Bitinis N.,CSIC - Institute of Polymer Science and Technology |
Fortunati E.,University of Perugia |
Verdejo R.,CSIC - Institute of Polymer Science and Technology |
Bras J.,Laboratory of Pulp and Paper Science |
And 4 more authors.
Carbohydrate Polymers | Year: 2013
The crystallization, mechanical and biodegradation properties of poly(lactic acid)/natural rubber/ cellulose nanocrystals (CNC) bionanocomposites were evaluated. Three types of CNC were used in this study, one unmodified (CNC), long alkyl chain grafted CNC (C18-g-CNC) and PLA grafted CNC (PLA-g-CNC). The CNC modifications determined the affinity of the nanocrystals toward the polymers and reflected on the ultimate properties. Interestingly, PLA-g-CNC acted as a nucleating agent for the PLA matrix in the bio-based PLA/NR blend. Good mechanical properties were reported, as the bionanocomposites maintained a high elongation at break for a concentration up to 3 wt.% of cellulose nanocrystals. Moreover, the disintegration study confirmed that the materials completely disintegrated after one month in compost. © 2013 Elsevier Ltd. All rights reserved.
LeCorre D.,Laboratory of Pulp and Paper science |
Bras J.,Laboratory of Pulp and Paper science |
Dufresne A.,Laboratory of Pulp and Paper science
Journal of Nanoparticle Research | Year: 2011
Starch nanocrystals (SNC) are crystalline platelets resulting from the disruption of the semicrystalline structure of starch granules by the acid hydrolysis of amorphous parts. The aim of this study was to assess the influence of botanic origin and amylose content of native starches on the morphology and properties of resulting nanoparticles. SNC were prepared from five different starches normal maize, high amylose maize, waxy maize, potato, and wheat; covering three botanic origins, two crystalline types, and three range of amylose content (0, 25, and 70%) for maize starch. Different types of nanocrystals were obtained with a thickness ranging between 4 and 8 nm and diameter from about 50 to 120 nm depending on the source. The comparison of their morphology, crystallinity, and rheological properties is proposed for the first time. For the same amylose content, maize, potato, and wheat resulted in rather similar size and crystallinity of SNC proving the limited influence of the botanic origin. For the same botanic origin (maize), differences in size were more important indicating the influence of the amylopectin content. Also, particles tended to show square shapes with increasing native starch's amylopectin content and A-type crystalinity. Thus, only high amylose content starches should be avoided to prepare SNC. © 2011 Springer Science+Business Media B.V.
Kordoghli B.,University of Monastir |
Khiari R.,University of Monastir |
Khiari R.,Laboratory of Pulp and Paper Science |
Mhenni M.F.,University of Monastir |
And 2 more authors.
Applied Surface Science | Year: 2012
This paper describes an original technique aiming to improve the hydrophilic properties of polyester fibres. In this method, the sulfonation of the aromatic rings is carried out using gaseous sulfur trioxide activated by UV irradiations. Thus, exposing the polyester textile fabric to the UVC light (wavelength around 254 nm) under a stream of sulfur trioxide leads to the fixation of SO 3H groups. The amounts of the fixed sulfonate groups depended on the reaction conditions. Evidence of grafting deduced from the measurements of hygroscopic properties was carried out by contact angle measurement, moisture regain as well as by measuring the rate of retention. SEM and FT-IR analysis, DSC and DTA/TGA thermograms showed that no significant modifications have occurred in the bulk of the treated PET fabrics. © 2012 Elsevier B.V.
Kamel S.,National Research Center of Egypt |
El-Gendy A.A.,National Research Center of Egypt |
El-Sakhawy M.,National Research Center of Egypt |
Belgacem M.N.,Laboratory of Pulp and Paper Science
Egyptian Journal of Chemistry | Year: 2015
SURFACE modification of bagasse paper sheet was carried out using silane derivatives, n-octyl triethoxysilane or perfluoro octyltriethoxy silane, in an ethanol/water medium. The change of sheet surface properties after modification was ascertained by contact angle measurements, scanning electron microscopy and FUR. The capability of the treated bagasse sheet to absorb engine oil from aqueous solution was studied. It was found that the treated sheet was significantly more hydrophobic than the untreated sheet. Treated sheet had little affinity for water and good affinity for oil.