scholarly journals Fully Biobased Reactive Extrusion of Biocomposites Based on PLA Blends and Hazelnut Shell Powders (HSP)

Chemistry ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 1464-1480
Author(s):  
Luca Panariello ◽  
Maria-Beatrice Coltelli ◽  
Alessandro Vannozzi ◽  
Daniele Bonacchi ◽  
Laura Aliotta ◽  
...  
Keyword(s):  
Malic Acid ◽  
Natural Fiber ◽  
Dicarboxylic Acids ◽  
Chain Scission ◽  
Poly Lactic Acid ◽  
Reactive System ◽  
Melt Mixing ◽  
Melt Viscosity ◽  
Hazelnut Shell ◽  
Chain Extenders

The production of biocomposites based on natural fiber waste and biopolymers is constantly increasing because of their renewability, biodegradability, and the accordance with the circular economy principles. The aim of this work is to contrast the disadvantages in the production of biocomposites, such as reduction of molecular weight through the use of biobased chain extenders. For this purpose, epoxidized soybean oil (ESO) and dicarboxylic acids (DCAs) were used to contrast the slight chain scission observed in a poly(lactic acid) (PLA)/poly(butylene succinate-co-adipate) (PBSA) binary blend caused by the melt mixing with hazelnut shell powder (HSP). Two different dimensions of HSPs were considered in this study as well as different concentrations of the ESO/DCA system, comparing succinic acid and malic acid as dicarboxylic acids. Melt viscosity parameters, such as torque and melt volume rate (MVR), were measured to investigate the chain extender effect during the extrusion. In addition, the reactivity of the ESO/DCA system was investigated through infrared spectroscopy. The effect of chain extenders on thermal properties, in particular on the crystallinity of PLA, and on mechanical properties of final biocomposites was investigated to understand their potentialities in industrial application. Results of this study evidenced a modest increase in melt viscosity due to ESO/malic acid chain extension system, but only for the HSP with the lower dimension (so the higher surface area) and adding 0.5 wt.% of ESO/malic acid. Thus, the slight chain scission of polyesters, not significantly affecting the final properties of these biocomposites, is the most relevant effect that was revealed in this complex reactive system.

scholarly journals Bamboo Fiber Based Cellulose Nanocrystals/Poly(Lactic Acid)/Poly(Butylene Succinate) Nanocomposites: Morphological, Mechanical and Thermal Properties

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1076
Author(s):  
Masrat Rasheed ◽  
Mohammad Jawaid ◽  
Bisma Parveez
Keyword(s):  
Lactic Acid ◽  
Thermal Properties ◽  
Cellulose Nanocrystals ◽  
Natural Fiber ◽  
Testing Machine ◽  
Bamboo Fiber ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Melt Mixing ◽  
Butylene Succinate

The purpose of this work was to investigate the effect of cellulose nanocrystals (CNC) from bamboo fiber on the properties of poly (lactic acid) (PLA)/poly (butylene succinate) (PBS) composites fabricated by melt mixing at 175 °C and then hot pressing at 180 °C. PBS and CNC (0.5, 0.75, 1, 1.5 wt.%) were added to improvise the properties of PLA. The morphological, physiochemical and crystallinity properties of nanocomposites were analysed by field emission scanning electron microscope (FESEM), Fourier-transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD), respectively. The thermal and tensile properties were analysed by thermogravimetic analysis (TGA), Differential scanning calorimetry (DSC) and Universal testing machine (UTM). PLA-PBS blend shows homogeneous morphology while the composite shows rod-like CNC particles, which are embedded in the polymer matrix. The uniform distribution of CNC particles in the nanocomposites improves their thermal stability, tensile strength and tensile modulus up to 1 wt.%; however, their elongation at break decreases. Thus, CNC addition in PLA-PBS matrix improves structural and thermal properties of the composite. The composite, thus developed, using CNC (a natural fiber) and PLA-PBS (biodegradable polymers) could be of immense importance as they could allow complete degradation in soil, making it a potential alternative material to existing packaging materials in the market that could be environment friendly.

scholarly journals The Effect of Surface Treatment with Isocyanate and Aromatic Carbodiimide of Thermally Expanded Vermiculite Used as a Functional Filler for Polylactide-Based Composites

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 890
Author(s):  
Mateusz Barczewski ◽  
Olga Mysiukiewicz ◽  
Aleksander Hejna ◽  
Radosław Biskup ◽  
Joanna Szulc ◽  
...  
Keyword(s):  
Impact Strength ◽  
Mechanical Stability ◽  
Thermomechanical Analysis ◽  
Thermomechanical Properties ◽  
Phenyl Isocyanate ◽  
Sem Analysis ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Expanded Vermiculite ◽  
Chain Extenders

In this work, thermally expanded vermiculite (TE-VMT) was surface modified and used as a filler for composites with a polylactide (PLA) matrix. Modification of vermiculite was realized by simultaneous ball milling with the presence of two PLA chain extenders, aromatic carbodiimide (KI), and 4,4’-methylenebis(phenyl isocyanate) (MDI). In addition to analyzing the particle size of the filler subjected to processing, the efficiency of mechanochemical modification was evaluated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The composites of PLA with three vermiculite types were prepared by melt mixing and subjected to mechanical, thermomechanical, thermal, and structural evaluation. The structure of composites containing a constant amount of the filler (20 wt%) was assessed using FTIR spectroscopy and SEM analysis supplemented by evaluating the final injection-molded samples’ physicochemical properties. Mechanical behavior of the composites was assessed by static tensile test and impact strength hardness measurements. Heat deflection temperature (HDT) test and dynamic thermomechanical analysis (DMTA) were applied to evaluate the influence of the filler addition and its functionalization on thermomechanical properties of PLA-based composites. Thermal properties were assessed by differential scanning calorimetry (DSC), pyrolysis combustion flow calorimetry (PCFC), and thermogravimetric analysis (TGA). The use of filler-reactive chain extenders (CE) made it possible to change the vermiculite structure and obtain an improvement in interfacial adhesion and more favorable filler dispersions in the matrix. This translated into an improvement in impact strength and an increase in thermo-mechanical stability and heat release capacity of composites containing modified vermiculites.

Microcellular foaming of poly(lactic acid) branched with food‐grade chain extenders

2021 ◽  
Vol 138 (29) ◽  
pp. 50686
Author(s):  
Krishnaa B. Venkatesan ◽  
Sonal S. Karkhanis ◽  
Laurent M. Matuana
Keyword(s):  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Food Grade ◽  
Microcellular Foaming ◽  
Chain Extenders

Super‐tough poly(lactic acid) using a fully bio‐based polyester containing malic acid via in‐situ interfacial compatibilization

2021 ◽  
pp. 51413
Author(s):  
Rong Yang ◽  
Hongwei Cao ◽  
Chong Li ◽  
Guoxiang Zou ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Malic Acid ◽  
Poly Lactic Acid

Biodegradation and Anti-Bacterial Properties of PLA and Wood/PLA Composites Incorporated with Zeomic Anti-Bacterial Agent

2013 ◽  
Vol 747 ◽  
pp. 111-114 ◽  
Author(s):  
Chana Prapruddivongs ◽  
Narongrit Sombatsompop
Keyword(s):  
Wood Flour ◽  
Viable Cell ◽  
Chain Scission ◽  
Plate Count ◽  
Poly Lactic Acid ◽  
Aerobic Degradation ◽  
Carbon Conversion ◽  
Plate Count Agar ◽  
Bacterial Agent ◽  
Biodegradation Test

Anti-bacterial and biodegradation activities of Poly (lactic acid) (PLA) and wood flour/PLA composites (WPLA) were investigated for the effect of anti-bacterial agent addition. Silver substituted Zeolite (commercially designated as Zeomic) was used as anti-bacterial agent in this study. Anti-bacterial activities were investigated through dynamic shake flask method accompanying with plate count agar (PCA) technique, against Staphylococcus aureus as testing bacteria. The results of anti-bacterial activity were reported by viable cell count. For biodegradation test, the degree and rate of biodegradations were evaluated from percentage of carbon conversion, the test being carried out under laboratory controlled-aerobic degradation environment at a temperature of 58±2°C. The results found that addition of Zeomic did not perform anti-bacterial activities for both the neat PLA and WPLA due to non-diffusivity of silver in Zeomic. For biodegradation test, both PLA and WPLA samples during incubation times of 21-60 days had shown considerable biodegradation rates as a result of chain scission by hydrolysis reaction and subsequent enzymatic-biodegradation by microorganism of PLA molecules. Regarding the effect of wood and Zeomic addition, it was found that introducing wood and Zeomic in PLA matrix tended to markedly increase the degree and rate of biodegradation of PLA and WPLA materials, whereby the PLA having 10%wt of wood with 1.5%wt of Zeomic had the most satisfactory biodegradation level and rate as a consequence of accelerated hydrolysis degradation from moisture in wood and Zeomic.

Sign in / Sign up

Export Citation Format

Share Document