Oriented and annealed poly(lactic acid) films and their performance in flexible printed and hybrid electronics

2021 ◽  
pp. 875608792098856
Author(s):  
Enni Luoma ◽  
Marja Välimäki ◽  
Teijo Rokkonen ◽  
Hannu Sääskilahti ◽  
Jyrki Ollila ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Light Emitting Diode ◽  
Tensile Modulus ◽  
Temperature Stability ◽  
High Heat ◽  
Pilot Scale ◽  
Electrical Performance ◽  
Poly Lactic Acid ◽  
Pet Film ◽  
The Stability

Flexible and hybrid electronics (FHE) are widely utilized from wearable to automotive applications. Instead of commonly used poly(ethylene terephthalate) (PET) film, bio-based and biodegradable polymer, poly(lactic acid) (PLA), is a most promising novel substrate alternative for FHE. From the point of heat curable conductive inks, the poor heat resistance and inherent brittleness are the major drawbacks of PLA. By increasing the PLA film crystallinity through orientation and annealing, its properties can be improved. Two commercial grades, standard PLA (PLA) and a high heat PLA (hhPLA), plus one stereocomplex PLA (scPLA) blend were used to compare PLA performance with different optical purities and crystallinity for printed FHE. Machine direction orientation (MDO), biaxial orientation (BO) and annealing improved the stability of the laboratory and pilot scale manufactured PLA films. MDO was more effective in improving stiffness and strength while BO resulted in more ductile behaviour. In hhPLA the crystallinity increased from 0% to 50% improving tensile strength by 83%, tensile modulus by 52% and strain at break from 3.7% to 114% with 3 × 3 BO and annealing. The scPLA blend contained homo- and stereocomplex crystallites and a double melting peak behaviour provided higher temperature stability through final melting at 220°C. Its optical transparency reached 95%, remaining high up to 250 nm wavelength. In roll-to-roll printing, the PLA and hhPLA films were dried at 100°C prior the printing and this decreased the MD elongation from 2.55% and 0.27% to 0.00–0.05%. The sheet resistance of printed silver was <40 mΩ/sq with additional drying for printed and hybrid integrated light-emitting diode (LED) foils. Printed LED foils on PLA had dimensional and electrical performance comparable to PET, even though lower drying temperatures were used.

Effect of Polyethylene Glycol in Nanocellulose/PLA Composites

2019 ◽  
Vol 821 ◽  
pp. 89-95
Author(s):  
Wanasorn Somphol ◽  
Thipjak Na Lampang ◽  
Paweena Prapainainar ◽  
Pongdhorn Sae-Oui ◽  
Surapich Loykulnant ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Polyethylene Glycol ◽  
Aspect Ratio ◽  
Mechanical Performance ◽  
Tensile Modulus ◽  
Poly Lactic Acid ◽  
Solvent Casting ◽  
Casting Method ◽  
Mediated Oxidation

Poly (lactic acid) or PLA was reinforced by nanocellulose and polyethylene glycol (PEG), which were introduced into PLA matrix from 0 to 3 wt.% to enhance compatibility and strength of the PLA. The nanocellulose was prepared by TEMPO-mediated oxidation from microcrystalline cellulose (MCC) powder and characterized by TEM, AFM, and XRD to reveal rod-like shaped nanocellulose with nanosized dimensions, high aspect ratio and high crystallinity. Films of nanocellulose/PEG/PLA nanocomposites were prepared by solvent casting method to evaluate the mechanical performance. It was found that the addition of PEG in nanocellulose-containing PLA films resulted in an increase in tensile modulus with only 1 wt% of PEG, where higher PEG concentrations negatively impacted the tensile strength. Furthermore, the tensile strength and modulus of nanocellulose/PEG/PLA nanocomposites were higher than the PLA/PEG composites due to the existence of nanocellulose chains. Visual traces of crazing were detailed to describe the deformation mechanism.

scholarly journals Effects of Rice Straw Powder (RSP) Size and Pretreatment on Properties of FDM 3D-Printed RSP/Poly(Lactic Acid) Biocomposites

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3234
Author(s):  
Wangwang Yu ◽  
Lili Dong ◽  
Wen Lei ◽  
Yuhan Zhou ◽  
Yongzhe Pu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Rice Straw ◽  
Fused Deposition Modeling ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Cost Effective ◽  
Poly Lactic Acid ◽  
Fused Deposition ◽  
Interfacial Compatibility ◽  
3D Printed

To develop a new kind of environment-friendly composite filament for fused deposition modeling (FDM) 3D printing, rice straw powder (RSP)/poly(lactic acid) (PLA) biocomposites were FDM-3D-printed, and the effects of the particle size and pretreatment of RSP on the properties of RSP/PLA biocomposites were investigated. The results indicated that the 120-mesh RSP/PLA biocomposites (named 120#RSP/PLA) showed better performance than RSP/PLA biocomposites prepared with other RSP sizes. Infrared results showed that pretreatment of RSP by different methods was successful, and scanning electron microscopy indicated that composites prepared after pretreatment exhibited good interfacial compatibility due to a preferable binding force between fiber and matrix. When RSP was synergistically pretreated by alkaline and ultrasound, the composite exhibited a high tensile strength, tensile modulus, flexural strength, and flexural modulus of 58.59, 568.68, 90.32, and 3218.12 MPa, respectively, reflecting an increase of 31.19%, 16.48%, 18.75%, and 25.27%, respectively, compared with unmodified 120#RSP/PLA. Pretreatment of RSP also improved the thermal stability and hydrophobic properties, while reducing the water absorption of 120#RSP/PLA. This work is believed to provide highlights of the development of cost-effective biocomposite filaments and improvement of the properties of FDM parts.

Mechanical, Thermal, and Morphological Properties of Thermoplastic Starch/Poly(lactic acid/Poly(butylene adipate-co-terephthalate) Blends

2014 ◽  
Vol 970 ◽  
pp. 312-316
Author(s):  
Sujaree Tachaphiboonsap ◽  
Kasama Jarukumjorn
Keyword(s):  
Lactic Acid ◽  
Impact Strength ◽  
Interfacial Adhesion ◽  
Tensile Modulus ◽  
Thermoplastic Starch ◽  
Morphological Properties ◽  
Poly Lactic Acid ◽  
Melt Blending ◽  
Elongation At Break ◽  
Blending Method

Thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend and thermoplastic starch (TPS)/poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend were prepared by melt blending method. PLA grafted with maleic anhydride (PLA-g-MA) was used as a compatibilizer to improve the compatibility of the blends. As TPS was incorporated into PLA, elongation at break was increased while tensile strength, tensile modulus, and impact strength were decreased. Tensile properties and impact properties of TPS/PLA blend were improved with adding PLA-g-MA indicating the enhancement of interfacial adhesion between PLA and TPS. With increasing PBAT content, elongation at break and impact strength of TPS/PLA blends were improved. The addition of TPS decreased glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm) of PLA. Tgand Tcof TPS/PLA blend were decreased by incorporating PLA-g-MA. However, the presence of PBAT reduced Tcof TPS/PLA blend. Thermal properties of TPS/PLA/PBAT blends did not change with increasing PBAT content. SEM micrographs revealed that the compatibilized TPS/PLA blends exhibited finer morphology when compared to the uncompatibilized TPS/PLA blend.

scholarly journals Impact Toughness and Ductility Enhancement of Biodegradable Poly(lactic acid)/Poly(ε-caprolactone) Blends via Addition of Glycidyl Methacrylate

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Kit Chee ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Mohd Faizal Abd Rahman ◽  
Buong Woei Chieng
Keyword(s):  
Lactic Acid ◽  
Impact Strength ◽  
Glycidyl Methacrylate ◽  
Interfacial Adhesion ◽  
Tensile Modulus ◽  
Sem Analysis ◽  
Poly Lactic Acid ◽  
Biodegradable Poly ◽  
Interfacial Compatibility ◽  
The Impact

Poly(lactic acid) (PLA)/poly(ε-caprolactone) (PCL) blends were prepared via melt blending technique. Glycidyl methacrylate (GMA) was added as reactive compatibilizer to improve the interfacial adhesion between immiscible phases of PLA and PCL matrices. Tensile test revealed that optimum in elongation at break of approximately 327% achieved when GMA loading was up to 3wt%. Slight drop in tensile strength and tensile modulus at optimum ratio suggested that the blends were tuned to be deformable. Flexural studies showed slight drop in flexural strength and modulus when GMA wt% increases as a result of improved flexibility by finer dispersion of PCL in PLA matrix. Besides, incorporation of GMA in the blends remarkably improved the impact strength. Highest impact strength was achieved (160% compared to pure PLA/PCL blend) when GMA loading was up to 3 wt%. SEM analysis revealed improved interfacial adhesion between PLA/PCL blends in the presence of GMA. Finer dispersion and smooth surface of the specimens were noted as GMA loading increases, indicating that addition of GMA eventually improved the interfacial compatibility of the nonmiscible blend.

Study on the Properties of Poly(lactic Acid) and Thermal Plastic Starch Blended Materials Plasticized by PEG 200

2012 ◽  
Vol 550-553 ◽  
pp. 813-817 ◽  
Author(s):  
Peng Liu ◽  
Cai Qin Gu ◽  
Qing Zhu Zeng ◽  
Hao Huai Liu
Keyword(s):  
Lactic Acid ◽  
Thermal Properties ◽  
Polyethylene Glycol ◽  
Rheological Properties ◽  
Tensile Properties ◽  
Tensile Modulus ◽  
Poly Lactic Acid ◽  
Pseudoplastic Fluid ◽  
Materials Properties ◽  
Plasticization Effect

In this paper, the blended materials of poly(lactic acid) (PLA) and thermal plastic starch (TPS) under the plasticization of polyethylene glycol (PEG) 200 were prepared. By detecting the thermal, rheological and tensile properties, it evaluated the plasticization effect of PEG 200 on blended materials. Specifically, for thermal properties, the addition of PEG 200 could improve mobile ability of PLA macromolecules, and accelerated them to form crystalline. But if the content of PEG 200 was more than 10%, this effect was impaired. For rheological properties, PEG 200 could change the fusant of blended materials from pseudoplastic fluid to newton fluid. However, if the PEG 200 was added too much, the blended material was too like perfect newton fluid to be prepared suitably. For tensile properties, when content of PEG 200 was more than 10%, the elongation and tensile modulus would changed sharply. All in all, 10% was the suitable addition parameter for PEG 200. Above this content, the plasticization effect of PEG 200 was too strong to impaired materials properties.

Effects of Graphene Nanopletelets on Poly(Lactic Acid)/Poly(Ethylene Glycol) Polymer Nanocomposites

2014 ◽  
Vol 1024 ◽  
pp. 136-139 ◽  
Author(s):  
Buong Woei Chieng ◽  
Ibrahim Nor Azowa ◽  
Wan Yunus Wan Md Zin ◽  
Mohd Zobir Hussein
Keyword(s):  
Lactic Acid ◽  
Ethylene Glycol ◽  
Tensile Properties ◽  
Tensile Modulus ◽  
Poly Lactic Acid ◽  
Poly Ethylene Glycol ◽  
Elongation At Break ◽  
Sem Image ◽  
Blending Method ◽  
Poly Ethylene

Graphene nanoplatelets (xGnP) were investigated as a novel nanoreinforcement filler in poly (lactic acid)(PLA)/poly (ethylene glycol)(PEG) blends by melt blending method. The prepared nanocomposites exhibited a significant improvement in tensile properties at a low xGnP loading. The tensile properties demonstrated the addition of 0.3wt% of xGnP led to an increase of up to 32.7%, 69.5% and 21.9% in tensile strength, tensile modulus and elongation at break of the nanocomposites respectively, compared to PLA/PEG blend. The nanocomposites also shows enhanced thermal stability compared with PLA/PEG blend in thermogravimetry analysis (TGA). Scanning electron microscopy (SEM) image of PLA/PEG/0.3wt% xGnP displays good uniformity and more homogenous morphology.

scholarly journals Effect of chitosan addition in starch and poly(lactic acid) sheets produced by extrusion

2015 ◽  
Vol 6 (1) ◽  
pp. 80
Author(s):  
Matheus Luz Alberti ◽  
Sílvio José De Souza ◽  
Heliberto Gonçalves ◽  
Fabio Yamashita ◽  
Marianne Ayumi Shirai
Keyword(s):  
Lactic Acid ◽  
Water Vapor ◽  
Food Packaging ◽  
Water Vapor Permeability ◽  
Barrier Properties ◽  
Extrusion Process ◽  
Pilot Scale ◽  
Poly Lactic Acid ◽  
Vapor Permeability ◽  
Water Vapor Barrier

<p>The use of blends containing biodegradable polymers like starch and poly (lactic acid) (PLA) has gained considerable attention, especially for the food packaging production. Current research has also highlighted the use of chitosan because their antimicrobial activity, biodegradability and applicability in the production of active biodegradable food packaging. The objective of this work was to produce cassava starch and PLA sheets incorporated with chitosan by flat extrusion process (calendering-extrusion), and evaluate the mechanical, water vapor barrier and microstructural properties. In order to simplify the obtainment of the material reducing processing steps, all components of the blend were homogenized in one step extrusion The incorporation of chitosan in the starch/PLA sheets decreased significantly the tensile strength, Young's modulus, elongation at break and density. In addition, the scanning electron microscopy images showed the formation of non-homogeneous mixtures with the presence of pores between the blend compounds, and this fact affected the water vapor barrier properties increasing water vapor permeability, solubility and diffusion coefficients. It was possible to conclude that although the incorporation of chitosan to the starch/PLA sheets has not contributed to obtain materials with suitable properties, it was able to produce them by calendering-extrusion process in pilot scale. Studies about chitosan incorporation in starch and PLA sheets still needed.</p><p>&nbsp;</p><p>DOI: 10.14685/rebrapa.v6i1.208</p><p>&nbsp;</p>

Bio-nanocomposites based on compatibilized poly(lactic acid) blend-reinforced agave cellulose nanocrystals

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5538-5555
Author(s):  
Noor Afizah Rosli ◽  
Wan Hafizi Wan Ishak ◽  
Siti Salwani Darwis ◽  
Ishak Ahmad ◽  
Mohammad Fauzul Azim Mohd Khairudin
Keyword(s):  
Lactic Acid ◽  
Water Absorption ◽  
Cellulose Nanocrystals ◽  
Tensile Modulus ◽  
Crystallization Rate ◽  
Tensile Tests ◽  
Absorption Capacity ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Green Materials

Enhancing the mechanical, thermal, and degradation properties of a poly(lactic acid) (PLA) blend without deteriorating its other useful features was the goal of this work. The isolation of cellulose nanocrystals (CNCs) from Agave angustifolia fibers was carried out, and the properties of the bio-nanocomposites comprising these CNCs were evaluated, which included PLA, natural rubber (NR), and liquid NR (LNR). Transmission electron microscopy and zeta potential analysis confirmed the successful isolation of CNCs from agave fibers after several chemical treatment steps. The effects of different CNC loadings on the properties of the bio-nanocomposites were investigated using tensile tests, thermal analysis, morphological analysis, and water absorption tests. Bio-nanocomposites containing 5 wt% and 7.5 wt% CNC had the optimal tensile modulus and strength, respectively. Different levels of CNC did not noticeably affect the thermal stability of the bio-nanocomposites, although the thermogram curves increased slightly as CNC content increased. The addition of CNC at different loadings affects the crystallization rate of PLA blend. The water absorption capacity increased as CNC level increased, and 5 wt% CNC gave rise to the highest water absorption. The four-component bio-nanocomposites created in this study provided an alternative for producing new green materials with tunable physical, mechanical, and thermal properties.

scholarly journals Poly (Lactic Acid)/Ground Tire Rubber Blends Using Peroxide Vulcanization

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1496
Author(s):  
Nicolas Candau ◽  
Oguzhan Oguz ◽  
Noel León Albiter ◽  
Gero Förster ◽  
Maria Lluïsa Maspoch
Keyword(s):  
Lactic Acid ◽  
Impact Strength ◽  
Crosslinking Agent ◽  
Mechanical Damage ◽  
Tensile Modulus ◽  
Poly Lactic Acid ◽  
Tire Rubber ◽  
Ground Tire Rubber ◽  
Clay Particles ◽  
Rubber Blends

Poly (Lactic Acid) (PLA)/Ground Tire Rubber (GTR) blends using Dicumyl peroxide (DCP) as a crosslinking agent were prepared with the following aims: propose a new route to recycle wastes rubber from the automotive industry and improve the toughness and impact strength of the inherently brittle bio-based PLA. The GTR were subjected to two types of grinding process (cryo- and dry ambient grinding). Swelling measurements revealed the grinding to be associated with a mechanical damage of the rubber chains, independently on the type of grinding or on the GTR size (from <400 µm to <63 µm). Moreover, the finest GTR contains the largest amount of reinforcing elements (carbon black, clay) that can be advantageously used in PLA/GTR blends. Indeed, the use of the finest cryo-grinded GTR in the presence of DCP showed the least decrease of the tensile strength (−30%); maintenance of the tensile modulus and the largest improvement of the strain at break (+80%), energy at break (+60%) and impact strength (+90%) as compared to the neat PLA. The results were attributed to the good dispersion of both fine GTR and clay particles into the PLA matrix. Moreover, a possible re-crosslinking of the GTR particles and/or co-crosslinking at PLA/GTR interface in presence of DCP is expected to contribute to such improved ductility and impact strength.

The effects of wettability, shear strength, and Weibull characteristics of fiber-reinforced poly(lactic acid) composites

2016 ◽  
Vol 36 (5) ◽  
pp. 489-497 ◽  
Author(s):  
John O. Akindoyo ◽  
Mohammad Dalour Hossen Beg ◽  
Suriati Ghazali ◽  
Muhammad Remanul Islam
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Lactic Acid ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Fiber Surface ◽  
Poly Lactic Acid ◽  
Dimethyl Siloxane ◽  
Pull Out ◽  
Relationship Of

Abstract The wettability, interfacial shear strength (IFSS), and Weibull characteristics of oil palm empty fruit bunch (EFB) fibers were studied to evaluate the mechanical properties of EFB- and poly(lactic acid) (PLA)-based composites. The fiber surface was modified through ultrasound and poly(dimethyl siloxane) treatment. The effects of treatment on the morphology, wettability, and structure of fibers were examined by scanning electron microscopy, contact angle, and Fourier transform infrared spectroscopy analysis, respectively. In addition, the Weibull characteristic was used to find the variability in strength of the fibers with respect to surface treatment. Furthermore, the IFSS of EFB fiber-PLA sandwich was investigated through single-fiber pull-out test, using a less strenuous technique. The mechanical properties (tensile strength, tensile modulus, flexural strength, and flexural modulus) of the composites were determined through mechanical testing. A comparison was drawn among the properties of PLA, raw EFB fiber-based composites, and treated EFB fiber-based composites. Additionally, the inter- and intra-relationship of fiber treatment, wettability, and IFSS with the mechanical properties of the PLA/EFB composites were also accounted.

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