Southampton, United Kingdom
Southampton, United Kingdom

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Quintana R.,Materia Nova | Quintana R.,University of Mons | Quintana R.,Institute of Materials Research and Engineering of Singapore | Persenaire O.,Materia Nova | And 6 more authors.
European Polymer Journal | Year: 2014

Cellulose acetate (CA) with a degree of substitution (DS) of 2.5 and polylactic acid (PLLA) were plasticized by melt extrusion using triacetin. Blends of resulting thermoplastic materials were then prepared and characterized by their tensile strength and differential scanning calorimetry (DSC). Thermal analysis revealed the invariability of the PLLA glass transition temperature in all blends, indicating that the compounds were immiscible. Grafted d/l lactide to CA copolymers were prepared by reactive melt processing using CA with different degree of substitution i.e. 2.1 and 2.5 and evaluated as CA/PLLA blend compatibilizer. The compatibility of the blends was investigated by scanning electron microscopy (SEM). Results showed that blend compatibility was improved evidencing the best performance of grafted copolymers with long grafted chains as blend compatibilizer of CA/PLLA blends. Finally, compatibilized blends compositions with enhanced ultimate elongation were achieved by using plasticized PLLA instead of neat PLLA. © 2014 Elsevier Ltd. All rights reserved.

Persenaire O.,Materia Nova | Quintana R.,Institute of Materials Research and Engineering of Singapore | Lemmouchi Y.,Group R and nter | Sampson J.,Group R and nter | And 3 more authors.
Polymer International | Year: 2014

The melt blending of poly(l-lactide) (PLLA) with biodegradable poly(butylene succinate) (PBS) is considered with a view to fine-tuning its mechanical properties and its degradability. For this purpose, both maleic-anhydride-grafted PLLA (PLLA-g-MA) and maleic-anhydride-grafted PBS (PBS-g-MA) were prepared and used as reactive compatibilizers. The influence of PBS melt viscosity on the morphology and mechanical properties of PLLA/PBS blends was studied. Interestingly, the blending of low viscosity PBS with PLLA allows PLLA to be toughened while the use of high viscosity PBS led to PLLA/PBS blends exhibiting co-continuous morphology. The nanostructure of the co-continuous blends may be tuned through the joint action of organo-modified clays and reactive compatibilizers. The effect of PBS on PLLA degradability was also investigated. The accelerated weathering testing of blends reveals that such combination of biodegradable polymers allows their degradability rate to be tailored. It is found that the addition of 20 wt% PBS to PLLA allows the molar mass loss fraction to be doubled after 425 h of testing. © 2014 Society of Chemical Industry.

Liu C.,Group R and nter | Feng S.,Group R and nter | Van Heemst J.,Group R and nter | McAdam K.G.,Group R and nter
Analytical and Bioanalytical Chemistry | Year: 2010

A sampling system has been set up to monitor a group of volatile smoke analytes (nitric oxide, acetaldehyde, acetone, benzene, toluene, 1,3 butadiene, isoprene and carbon dioxide) from mainstream cigarette smoke on a puff-resolved basis. The system was able to record gas evolution profiles during puffing and interpuff periods without interruption (e.g. taking clearing puffs). Gas phase smoke analytes were sampled as close to the mouth end of the cigarette filter as possible in order to minimise any dead volume effect. The results revealed that, for some volatile species, a significant fraction (e.g. up to 30% for benzene) in the cigarette mainstream smoke had been generated during the preceding smoulder period. These species were trapped or absorbed within the cigarette rod and then subsequently eluted during the puff. The identification of the two sources of the mainstream smoke, a smouldering source and a puffing source, has not been reported before. The observation contributes to the fundamental knowledge of the cigarette smoke formation and may have implications on wider smoke chemistry and associated effects.

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