scholarly journals Valorization of Hemp Hurds as Bio-Sourced Additives in PLA-Based Biocomposites

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3786
Author(s):  
Sina Momeni ◽  
Muhammad Safder ◽  
Mohammad Abu Hasan Khondoker ◽  
Anastasia Leila Elias
Keyword(s):  
Lactic Acid ◽  
Natural Fiber ◽  
Low Cost ◽  
Agricultural Waste ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Plant Fibers ◽  
Chemical Treatments ◽  
Alkaline Peroxide ◽  
Hemp Hurd

Sourced from agricultural waste, hemp hurds are a low-cost renewable material with high stiffness; however, despite their potential to be used as low-cost filler in natural fiber reinforced polymer biocomposites, they are often discarded. In this study, the potential to add value to hemp hurds by incorporating them into poly(lactic acid) (PLA) biopolymer to form bio-based materials for packaging applications is investigated. However, as with many plant fibers, the inherent hydrophilicity of hemp hurds leads to inferior filler-matrix interfacial interactions, compromising the mechanical properties of the resulting biocomposites. In this study, two chemical treatments, alkaline (NaOH) and alkaline/peroxide (NaOH/H2O2) were employed to treat hemp hurds to improve their miscibility with poly(lactic acid) (PLA) for the formation of biocomposites. The effects of reinforcement content (5, 10, and 15 wt. %), chemical treatments (purely alkaline vs. alkaline/peroxide) and treatment cycles (1 and 3 cycles) on the mechanical and thermal properties of the biocomposites were investigated. The biocomposites of treated hemp hurd powder exhibited enhanced thermal stability in the temperature range commonly used to process PLA (130–180 °C). The biocomposites containing 15 wt. % hemp hurd powder prepared using a single-cycle alkaline/peroxide treatment (PLA/15APHH1) exhibited a Young’s modulus of 2674 MPa, which is 70% higher than that of neat PLA and 9.3% higher than that of biocomposites comprised of PLA containing the same wt. % of untreated hemp hurd powder (PLA/15UHH). Furthermore, the tensile strength of the PLA/15APHH1 biocomposite was found to be 62.6 MPa, which was 6.5% lower than that of neat PLA and 23% higher than that of the PLA/15UHH sample. The results suggest that the fabricated PLA/hemp hurd powder biocomposites have great potential to be utilized in green and sustainable packaging applications.

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.

Effect of the compatilizer and chemical treatments on the performance of poly(lactic acid)/ramie fiber composites

2021 ◽  
pp. 100843
Author(s):  
Jianghu Zhan ◽  
Guilong Wang ◽  
Jiao Li ◽  
Yanjin Guan ◽  
Guoqun Zhao ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Fiber Composites ◽  
Poly Lactic Acid ◽  
Ramie Fiber ◽  
Chemical Treatments

Influence of extrusion screw speed on the properties of halloysite nanotube impregnated polylactic acid nanocomposites

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Chaitra Venkatesh ◽  
Yuanyuan Chen ◽  
Zhi Cao ◽  
Shane Brennan ◽  
Ian Major ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Composite Films ◽  
Polymer Melt ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Screw Speed ◽  
Halloysite Nanotube ◽  
The Past

Abstract Poly (lactic acid)/halloysite nanotube (PLA/HNT) nanocomposites have been studied extensively over the past few years owing to the interesting properties of the polymer, PLA, and the nanoclay, HNT, individually and as composites. In this paper, the influence of the screw speed during extrusion was investigated and was found to have a significant impact on the mechanical and thermal performance of the extruded PLA/HNT nanocomposites. To determine the effect of screw speed on PLA/HNT nanocomposites, 5 and 10 wt% of HNTs were blended into the PLA matrix through compounding at screw speeds of 40, 80, and 140 rpm. Virgin PLA was compounded for comparison. The resultant polymer melt was quench cooled onto a calendar system to produce composite films which were assessed for mechanical, thermal, chemical, and surface properties. Results illustrate that in comparison to 40 and 80 rpm, the virgin PLA when compounded at 140 rpm, indicated a significant increase in the mechanical properties. The PLA/HNT 5 wt% nanocomposite compounded at 140 rpm showed significant improvement in the dispersion of HNTs in the PLA matrix which in turn enhanced the mechanical and thermal properties. This can be attributed to the increased melt shear at higher screw speeds.

scholarly journals Performance of lightweight mortar reinforced with doum palm fiber

2020 ◽  
pp. 002199832097519
Author(s):  
Fatma Naiiri ◽  
Allègue Lamis ◽  
Salem Mehdi ◽  
Zitoune Redouane ◽  
Zidi Mondher
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
Natural Fiber ◽  
Cement Mortar ◽  
Low Cost ◽  
Natural Fibers ◽  
Construction Materials ◽  
Mechanical And Thermal Properties ◽  
Palm Fiber ◽  
And Control

Natural fibers are increasingly used in composites because of their low cost and good mechanical properties. Cement reinforced with natural fibersis contemplates as a new generation of construction materials with superior mechanical and thermal performance. This study of three sizes’effect of Doum palm fiber explores the mortar’s behavior reinforced with different fiber ratio. The aim is to determine the optimal addition to improve mechanical and thermal properties of natural fiber reinforced cements. Physical, mechanical and thermal properties of composite are examined. Tensile properties of Doum fibers are verified to determine their potential as reinforced material. Findings prove that the use of alkali-treated Doum fiber as reinforcement in cement mortar composite leads to the upgrading of the mechanical properties including thermo-physical properties against composites reinforced with raw fibers and control cement mortars. While, the compression and flexural strength of the cement mortar reinforced with alkali-treated Doum fiber with diameter 0.3 mm (CT3) are metered to be 11.11 MPa, 5.22 MPa, respectively for fiber content 0.5%. Additionally, based on thermo-physical tests, it is assessed that the thermal conductivity and diffusivity decrease for cement mortar reinforced with Doum fiber with diameter 0.2 mm (CT2).

Preparation and Characterization of Micro-Graphite Filled Poly(Lactic Acid) Composites: Part 1 - Rheological and Thermal Properties

2020 ◽  
Vol 981 ◽  
pp. 138-143
Author(s):  
Esa N. Shohih ◽  
Mujtahid Kaavessina ◽  
Henry A. S. Lomi ◽  
Betha P. Pratiwi ◽  
Sperisa Distantina ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Conductive Polymer ◽  
Complex Viscosity ◽  
Poly Lactic Acid ◽  
Homogeneous Distribution ◽  
Mechanical And Thermal Properties ◽  
Blending Method ◽  
Stirring Time

Conductive polymer composites (CPCs) have attracted great attention of researchers due to their enhanced properties such as an adjustable electrical conductivity, good processability, good mechanical and thermal properties, etc. CPCs had many potencies for wider application in electronic devices. Poly (lactic acid) or PLA is one of the interesting polymers used in the developing of these new important materials. PLA properties are comparable to the synthetic petroleum-based polymers such as polyethylene terephthalate (PET), polypropylene (PP), etc. This research focuses on studying the rheological and thermal properties of PLA/micro-graphite as a conductive polymer composite which adjustable its electrical conductivity. In this study, the PLA/micro-graphite was prepared through solvent blending method using chloroform. The micro-graphite composition was varied from 0%, 5%, and 10 % (w/w) with different stirring time (30 and 60 minutes) and then, poured in glass mould. In the melt rheology study, the frequency sweep test showed that the complex viscosity (|η*|) of the bio-composite increased with the micro-graphite loading. The same tendency was also found in thermal property and stability. The melting temperature and thermal degradation were slightly increasing. The crystallinity of PLA was influenced by the presence of micro-graphite. In this solvent blending method, the homogeneous distribution of micro-graphite in the bio-composite required at least 60 minutes (stirred at 650 rpm and 60 °C).

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