scholarly journals Degradation of a mechanically recycled polylactide/halloysite nanocomposite in an ethanolic food simulant

2021 ◽  
Vol 2 (2) ◽  
pp. 63
Author(s):  
Freddys R. Beltrán ◽  
Marina P. Arrieta ◽  
Yaiza Hortal ◽  
Gerald Gaspar ◽  
Mª Ulagares De la Orden ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Intrinsic Viscosity ◽  
Mechanical Performance ◽  
Halloysite Nanotubes ◽  
Ethanol Solution ◽  
Poly Lactic Acid ◽  
Accelerated Ageing ◽  
Food Simulant ◽  
Before And After ◽  
Hardness Values

<p class="JARTEAbstract">This work aims to study the effect of immersion in a ethanolic food simulant in mechanically recycled poly(lactic acid) (PLAR) and its nanocomposites reinforced with halloysite nanotubes (HNT). PLAR was obtained by subjecting PLA to an accelerated ageing process, which includes photochemical, thermal and hydrothermal ageing steps, followed by a final demanding washing step. PLAR was further reinforced with 4 %wt. HNT to improve the properties of the PLAR films. The materials were melt compounded by melt extrusion and processed into films by compression molding. The resulting films were exposed to food simulant D1 (50 %vol. ethanol solution) for 10 days at 40 °C. The intrinsic viscosity, crystallization behavior, thermal stability as well as the mechanical performance were analyzed before and after the contact with the food simulant. The swelling, plasticizing and hydrolyzing effect of the food simulant led to an important decrease of the intrinsic viscosity of all the samples, along with a significant increase of the crystallinity. Thermal stability was negatively affected by the decrease of the molecular weight, while the high crystallinity values resulted in materials with higher Vickers hardness values after the immersion in the food simulant.</p>

scholarly journals Cellulose Nanofibrils Filled Poly(Lactic Acid) Biocomposite Filament for FDM 3D Printing

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2319 ◽  
Author(s):  
Qianqian Wang ◽  
Chencheng Ji ◽  
Lushan Sun ◽  
Jianzhong Sun ◽  
Jun Liu
Keyword(s):  
Thermal Stability ◽  
3D Printing ◽  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Cellulose Nanofibrils ◽  
Poly Lactic Acid ◽  
Fused Deposition ◽  
Wide Range ◽  
The Matrix ◽  
Direct Digital Manufacturing

As direct digital manufacturing, 3D printing (3DP) technology provides new development directions and opportunities for the high-value utilization of a wide range of biological materials. Cellulose nanofibrils (CNF) and polylactic acid (PLA) biocomposite filaments for fused deposition modeling (FDM) 3DP were developed in this study. Firstly, CNF was isolated by enzymatic hydrolysis combined with high-pressure homogenization. CNF/PLA filaments were then prepared by melt-extrusion of PLA as the matrix and CNF as the filler. Thermal stability, mechanical performance, and water absorption property of biocomposite filaments and 3D-printed objects were analyzed. Findings showed that CNF increased the thermal stability of the PLA/PEG600/CNF composite. Compared to unfilled PLA FDM filaments, the CNF filled PLA biocomposite filament showed an increase of 33% in tensile strength and 19% in elongation at break, suggesting better compatibility for desktop FDM 3DP. This study provided a new potential for the high-value utilization of CNF in 3DP in consumer product applications.

scholarly journals Hybrid Biocomposites Based on Poly(Lactic Acid) and Silica Aerogel for Food Packaging Applications

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4910 ◽  
Author(s):  
Alejandro Aragón-Gutierrez ◽  
Marina P. Arrieta ◽  
Mar López-González ◽  
Marta Fernández-García ◽  
Daniel López
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Silica Aerogel ◽  
Food Packaging ◽  
Mechanical Performance ◽  
Composite Films ◽  
Barrier Properties ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Barrier Performance

Bionanocomposites based on poly (lactic acid) (PLA) and silica aerogel (SiA) were developed by means of melt extrusion process. PLA-SiA composite films were plasticized with 15 wt.% of acetyl (tributyl citrate) (ATBC) to facilitate the PLA processability as well as to attain flexible polymeric formulations for films for food packaging purposes. Meanwhile, SiA was added in four different proportions (0.5, 1, 3 and 5 wt.%) to evaluate the ability of SiA to improve the thermal, mechanical, and barrier performance of the bionanocomposites. The mechanical performance, thermal stability as well as the barrier properties against different gases (carbon dioxide, nitrogen, and oxygen) of the bionanocomposites were evaluated. It was observed that the addition of 3 wt.% of SiA to the plasticized PLA-ATBC matrix showed simultaneously an improvement on the thermal stability as well as the mechanical and barrier performance of films. Finally, PLA-SiA film formulations were disintegrated in compost at the lab-scale level. The combination of ATBC and SiA sped up the disintegration of PLA matrix. Thus, the bionanocomposites produced here show great potential as sustainable polymeric formulations with interest in the food packaging sector.

Mechanical and Thermal Properties of PLA Melt Blended with High Molecular Weight PEG Modified with Peroxide and Organo-Clay

2017 ◽  
Vol 751 ◽  
pp. 337-343 ◽  
Author(s):  
Chanchai Thongpina ◽  
Chaiwat Tippuwanan ◽  
Kwanchai Buaksuntear ◽  
Teerani Chuawittayawuta
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Mechanical Performance ◽  
Organic Peroxide ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Cloisite 30B

The thermal and mechanical properties of poly (lactic acid) blended with high molecular weight PEG, i.e. PEG1000 and PEG6000 were compared. The contents of PEG added were 10, 12.5 and 15 % by weight, with respect to PLA. The PLA/PEG blends were modified by addition of organic peroxide in order to induced crosslinking. Addition of organic modified montmorrillonite (Cloisite 30B, C30B) was also performed in order to modify mechanical performance of PLA/PEG blends. C30B was prepared via master batch in PLA. Morphology, crystallization, thermal stability and mechanical properties of the blends were investigated using SEM, DSC, TGA and universal testing macine, respectively. Morphology of cryogenic fracture surface showed smooth brittle surface. PEG1000 well plasticized PLA where as PEG6000 shows better thermal stability and mechanical properties. The presence of PEG induced PLA to perform cold crystallization. Tm in PLA was slightly changed whereas degree of crystallinity of PLA was improved by PEG but slightly decreased by peroxide. The thermal stability of PLA was enhanced with the addtion of PEG6000. The toughening of PLA was confirmed by the increment of elongation at break. The exfoliation of C30B was interfered by the crosslink PLA. Then tensile strength of PLA/PEG/C30B/Luperox101 was then suppressed. The optimum properties, in term of toughening and thermal stability, were found at PEG content of 10 % rather than 15% by weight, for both PEG1000 and PEG6000.

Thermal stability of poly(lactic acid) before and after γ-radiolysis

1999 ◽  
Vol 48 (10) ◽  
pp. 980-984 ◽  
Author(s):  
A Babanalbandi ◽  
D J T Hill ◽  
D S Hunter ◽  
L Kettle
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Before And After ◽  
Thermal Stability Of

scholarly journals Weathering of Antibacterial Melt-Spun Polyfilaments Modified by Pine Rosin

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 876
Author(s):  
Mikko Kanerva ◽  
Jacob Mensah-Attipoe ◽  
Arja Puolakka ◽  
Timo M. Takala ◽  
Marko Hyttinen ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Degradation Process ◽  
Thermal Ageing ◽  
Poly Lactic Acid ◽  
Accelerated Ageing ◽  
Functional Additives ◽  
Volatile Organic ◽  
Melt Spun ◽  
Over Time ◽  
Killing Response

For many antibacterial polymer fibres, especially for those with natural functional additives, the antibacterial response might not last over time. Moreover, the mechanical performance of polymeric fibres degrades significantly during the intended operation, such as usage in textile and industrial filter applications. The degradation process and overall ageing can lead to emitted volatile organic compounds (VOCs). This work focused on the usage of pine rosin as natural antibacterial chemical and analysed the weathering of melt-spun polyethylene (PE) and poly lactic acid (PLA) polyfilaments. A selected copolymer surfactant, as an additional chemical, was studied to better integrate rosin with the molecular structure of the plastics. The results reveal that a high 20 w-% of rosin content can be obtained by surfactant addition in non-oriented PE and PLA melt-spun polyfilaments. According to the VOC analysis, interestingly, the total emissions from the melt-spun PE and PLA fibres were lower for rosin-modified (10 w-%) fibres and when analysed below 60 ℃. The PE fibres of the polyfilaments were found to be clearly more durable in terms of the entire weathering study, i.e., five weeks of ultraviolet radiation, thermal ageing and standard washing. The antibacterial response against Gram-positive Staphylococcus aureus by the rosin-containing fibres was determined to be at the same level (decrease of 3–5 logs cfu/mL) as when using 1.0 w-% of commercial silver-containing antimicrobial. For the PE polyfilaments with rosin (10 w-%), full killing response (decrease of 3–5 logs cfu/mL) remained after four weeks of accelerated ageing at 60 ℃.

Thermomechanical Study and Thermal Behavior of Plasticized Poly(Lactic Acid) Nanocomposites

2021 ◽  
Vol 317 ◽  
pp. 333-340
Author(s):  
Mohammed Zorah ◽  
Izan Roshawaty Mustapa ◽  
Norlinda Daud ◽  
Nahida Jumah ◽  
Nur Ain Syafiqah Sudin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Lactic Acid ◽  
Thermal Behavior ◽  
Food Packaging ◽  
Mechanical Performance ◽  
Poly Lactic Acid ◽  
Solvent Casting ◽  
Thermal And Mechanical Properties ◽  
Hot Press

Poly (lactic acid) (PLA) is a useful alternative to petrochemical commodity material used in such as in food packaging industries. Due to its inherent brittleness, low thermal stability, and poor crystallization, it needs to improve its properties, namely in terms of thermal and mechanical performance. The plasticized PLA composites reinforced with nanofiller were prepared by solvent casting and hot press methods. Thermal and mechanical properties, as well as the crystallinity study of these nanocomposites, were investigated to study the effect of tributyl citrate (TBC) and TiO2 on the PLA composites. The addition of TBC improved the flexibility and crystallinity of the composites. Reinforcement of TiO2 was found as a practical approach to improve the mechanical properties, thermal stability, and enhanced crystalline ability for plasticized PLA nanocomposites. Based on the results achieved in this study, the composite with 3.5% nanofiller (pPLATi3.5) presented the optimum set of mechanical properties and improved thermal stability.

scholarly journals Fabrication of High-Performance Bamboo–Plastic Composites Reinforced by Natural Halloysite Nanotubes

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2259
Author(s):  
Xiaobei Jin ◽  
Jingpeng Li ◽  
Rong Zhang ◽  
Zehui Jiang ◽  
Daochun Qin
Keyword(s):  
Thermal Stability ◽  
High Performance ◽  
Moisture Absorption ◽  
Mechanical Performance ◽  
Halloysite Nanotubes ◽  
Industrial Applications ◽  
High Concentration ◽  
Morphological Studies ◽  
Plastic Composites ◽  
The Impact

Bamboo-plastic composites (BPCs) as new biomass-plastic composites have recently attracted much attention. However, weak mechanical performance and high moisture absorption as well as low thermal stability greatly limit their industrial applications. In this context, different amounts of halloysite nanotubes (HNTs) were used as a natural reinforcing filler for BPCs. It was found that the thermal stability of BPCs increased with increasing HNT contents. The mechanical strength of BPCs was improved with the increase in HNT loading up to 4 wt% and then worsened, while the impact strengths were slightly reduced. Low HNT content (below 4 wt%) also improved the dynamic thermomechanical properties and reduced the water absorption of the BPCs. Morphological studies confirmed the improved interfacial compatibility of the BPC matrix with 4 wt% HNT loading, and high-concentration HNT loading (above 6 wt%) resulted in easy agglomeration. The results highlight that HNTs could be a feasible candidate as nanoreinforcements for the development of high-performance BPCs.

scholarly journals Effect of Iignocellulosic Nanoparticles Extracted from Yerba Mate (Ilex paraguariensis) on the Structural, Thermal, Optical and Barrier Properties of Mechanically Recycled Poly(lactic acid)

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1690
Author(s):  
Freddys R. Beltrán ◽  
Marina P. Arrieta ◽  
Gerald Gaspar ◽  
María U. de la Orden ◽  
Joaquín Martínez Urreaga
Keyword(s):  
Food Packaging ◽  
Mechanical Performance ◽  
Barrier Properties ◽  
Poly Lactic Acid ◽  
Accelerated Ageing ◽  
Ilex Paraguariensis ◽  
Yerba Mate ◽  
Bionanocomposite Films ◽  
Overall Performance ◽  
Crystalline Domains

In this work, yerba mate nanoparticles (YMNs) were extracted from Ilex paraguairiencis yerba mate wastes and further used to improve the overall performance of mechanically recycled PLA (PLAR). Recycled PLA was obtained by melt reprocessing PLA subjected to an accelerated ageing process, which involved photochemical, thermal and hydrothermal ageing steps, as well as a final demanding washing step. YMNs (1 and 3 wt. %) were added to the PLAR during the melt reprocessing step and further processed into films. The main goal of the development of PLAR-YMNs bionanocomposites was to increase the barrier properties of recycled PLA, while showing good overall performance for food packaging applications. Thus, optical, structural, thermal, mechanical and barrier properties were evaluated. The incorporation of YMNs led to transparent greenish PLAR-based films with an effective blockage of harmful UV radiation. From the backbone FTIR stretching region (bands at 955 and 920 cm−1), it seems that YMNs favor the formation of crystalline domains acting as nucleating agents for PLAR. The morphological investigations revealed the good dispersion of YMNs in PLAR when they are used in the lowest amount of 1 wt. %, leading to bionanocomposites with improved mechanical performance. Although the addition of high hydrophilic YMNs increased the water vapor transmission, the addition of 1 wt. % of YMNs enhanced the oxygen barrier performance of the produced bionanocomposite films. These results show that the synergistic revalorization of post-consumer PLA and nanoparticles obtained from agri-food waste is a potential way for the production of promising packaging materials that meet with the principles of the circular economy.

Effect of carbonization on mechanical properties of halloysite nanotube-FRP nanocomposites with different morphological structures

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940021
Author(s):  
Yun-Hae Kim ◽  
Ji-Su Choi ◽  
Soo-Jeong Park
Keyword(s):  
Thermal Stability ◽  
Bonding Strength ◽  
Basalt Fiber ◽  
Morphological Structure ◽  
Halloysite Nanotubes ◽  
Interfacial Bonding ◽  
Limiting Oxygen Index ◽  
Excellent Thermal Stability ◽  
Interfacial Bonding Strength ◽  
Before And After

In this study, halloysite nanotubes (HNTs), an environmentally friendly inorganic nanomaterial, was added to epoxy matrix glass and basalt fiber reinforced plastics (GFRP and BFRP) by heat treatment of HNTs with crystalline and amorphous structure at [Formula: see text] and [Formula: see text]. Their interfacial bonding strength and effect of HNTs before and after carbonization by flame were analyzed. We found that the HNT/epoxy formed a physical barrier on the surface because of the char generated by carbonization. The barrier showed excellent thermal stability and limiting oxygen index in BFRP. The flexural strength after carbonization was low in the amorphous 1000HTHNT-BFRP with strong interfacial bonding. In other words, the morphological structure of the HNTs helped the improvement of the interfacial bonding strength; hence, the reinforcing effect of the HNTs on the thermal stability and mechanical strength before and after carbonization can be controlled.

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