Cover Page March-2019-Advanced Materials Letters

Advanced Materials Letters

Volume 10, Issue 3, Pages 206-214, March 2019
About Cover

The cover photo describes the scheme of the twin screw extruder for the preparation of thermoplastic starch (TPS).  As discussed by M. Paula Guarás, this screw extrusion process is very advantageous for the preparation of TPS films with improved mechanical and water vapor absorption properties in any industrial processing line for plastic packaging products. 


Effect of storage time, plasticizer formulation and extrusion parameters on the performance of thermoplastic starch films

M. Paula Guarás*, Vera A. Alvarez, Leandro N. Ludueña

Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones en Ciencia y Tecnología de Materiales (INTEMA), Grupo de Materiales Compuestos Termoplásticos (CoMP), Facultad de Ingeniería, Universidad Nacional de Mar del Plata, Av. Colón 10850 (B7606BVZ) Mar del Plata, Argentina

Adv. Mater. Lett., 2019, 10 (3), pp 206-214

DOI: 10.5185/amlett.2019.2205

Publication Date (Web): Dec 31, 2018

E-mail: paula.guaras@gmail.com, luduenaunmdp@gmail.com, alvarezvera@gmail.com

Abstract

A twin screw extrusion processing method was developed for the preparation of thermoplastic starch (TPS) for packaging applications. Different plasticizer combinations were used looking for the minimal temperature profile in the extruder in order to prevent the thermal degradation of TPS. The effect of storage time at 25 °C and 50% of relative humidity on the properties of TPS was studied. Plasticized TPS samples observed by scanning electron microscopy showed homogeneous fracture surfaces without unstructured starch granules. X-ray diffractometry tests showed retro gradation of all TPS formulations with progressive Vh-type crystal structure formation. Temperature for maximum thermal degradation rate of raw materials was shifted to higher values after preparing the TPS, suggesting not only physical but also chemical interactions between plasticizers and starch molecules. Mechanical properties were significantly improved replacing 10 wt. % of glycerol by water as plasticizer, which was attributed to the increased gelatinization degree and the reduction of thermal degradation. 

Keywords

Thermoplastic starch, processing condition, formulation, storage time.

Current Issue

Smart Healthcare pulls up Clouds for Virtual Medicine


Selecting the correct electromagnetic inspection technology 


Influence of railway-track grinding on the track material condition and tribological behaviour


Micromechanical Fatigue Modelling of the Size Effect in Micro-Scale 316L Stainless Steel Specimens


Functionalization of Graphene and Reduced Graphene Oxide in Different Matrices


Effect of parasitic polytypes on ballistic electron transport in chemical vapor deposition grown 6H-SiC epitaxial layers


Photomemristive heterostructures based on two-dimensional crystals


Architecture - behaviour - properties relationship in Star-shaped MPA-PMMA and MPA-PS hyper-branched copolymers


Graphene and doped graphene: A comparative DFT study


Ag2CO3 / Magnetic reduced graphene oxide nanocomposite as advanced visible light photocatalytic hybrid materials for efficient degradation of azo dye


Optimization of acid hydrolysis process for the preparation cellulose nanofibrils


Alginate/k-carrageenan and alginate/gelatin composite hydrogel beads for controlled drug release of curcumin


Study of microstructure and mechanical properties of friction stir welded ferrite-martensite DP700 steel


Previous issues

9th Anniversary of Advanced Materials Letters: Progress and Opportunities

Coating - A potent method to enhance electrochemical performance of Li(NixMnyCoz)O2 cathodes for Li-ion batteries

Analysis of machined electron beam treated Ti6Al4V-ELI implant surfaces

Bottom-up design of hydrogels through click-chemistry modification of magnetic nanoparticles

Visualization of mechanical loads with semiconductor nanocrystals 

Room temperature growth of ultra porous hot-wire deposited tantalum pentoxide

Substrate integrated circular cavity resonator filled with nano-fibrillated cellulose for humidity detection

Oxygen vacancy filament-based resistive switching in Hf0.5Zr0.5O2 thin films for non-volatile memory

Innovative silicon compatible materials for light emitting devices  

Graphene micromesh for transparent conductive films application 

Applications of nano-scale Cirrus DopantTM to improve existing coatings

Chitin nanofibrils in renewable materials for packaging and personal care applications

Synthesis of AgNPs embedded double network nanocomposite hydrogels having high swelling and anti-bacterial characteristics

Upcoming Congress

Knowledge Experience at Sea TM