scholarly journals Manipulating Crystallization for Simultaneous Improvement of Impact Strength and Heat Resistance of Plasticized Poly(l-lactic acid) and Poly(butylene succinate) Blends

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3066
Author(s):  
Todsapol Kajornprai ◽  
Supakij Suttiruengwong ◽  
Kalyanee Sirisinha
Keyword(s):  
Lactic Acid ◽  
Impact Toughness ◽  
Impact Strength ◽  
Heat Resistance ◽  
Decisive Role ◽  
Annealed Sample ◽  
Crystalline Morphology ◽  
Butylene Succinate ◽  
Poly Ethylene ◽  
Short Time

Crystalline morphology and phase structure play a decisive role in determining the properties of polymer blends. In this research, biodegradable blends of poly(l-lactic acid) (PLLA) and poly(butylene succinate) (PBS) have been prepared by melt-extrusion and molded into specimens with rapid cooling. The crystalline morphology (e.g., crystallinity, crystal type and perfection) is manipulated by annealing the molded products from solid-state within a short time. This work emphasizes on the effects of annealing conditions on crystallization and properties of the blends, especially impact toughness and thermal stability. Phase-separation morphology with PBS dispersed particles smaller than 1 μm is created in the blends. The blend properties are successfully dictated by controlling the crystalline morphology. Increasing crystallinity alone does not ensure the enhancement of impact toughness. A great improvement of impact strength and heat resistance is achieved when the PLLA/PBS (80/20) blends are plasticized with 5% medium molecular-weight poly(ethylene glycol), and simultaneously heat-treated at a temperature close to the cold-crystallization of PLLA. The plasticized blend annealed at 92 °C for only 10 min exhibits ten-fold impact strength over the starting PLLA and slightly higher heat distortion temperature. The microscopic study demonstrates the fracture mechanism changes from crazing to shear yielding in this annealed sample.

The effect of poly(ethylene glycol) as plasticizer in blends of poly(lactic acid) and poly(butylene succinate)

2015 ◽  
Vol 133 (8) ◽  
pp. n/a-n/a ◽  
Author(s):  
Weraporn Pivsa-Art ◽  
Kazunori Fujii ◽  
Keiichiro Nomura ◽  
Yuji Aso ◽  
Hitomi Ohara ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Ethylene Glycol ◽  
Poly Lactic Acid ◽  
Poly Ethylene Glycol ◽  
Butylene Succinate ◽  
Poly Ethylene

scholarly journals Cloning and Sequencing of a Poly(dl-Lactic Acid) Depolymerase Gene from Paenibacillus amylolyticus Strain TB-13 and Its Functional Expression in Escherichia coli

2003 ◽  
Vol 69 (5) ◽  
pp. 2498-2504 ◽  
Author(s):  
Yukie Akutsu-Shigeno ◽  
Teerawat Teeraphatpornchai ◽  
Kamonluck Teamtisong ◽  
Nobuhiko Nomura ◽  
Hiroo Uchiyama ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Amino Acid ◽  
Functional Expression ◽  
Amino Acid Residues ◽  
Cloning And Sequencing ◽  
Gene Encoding ◽  
Butylene Succinate ◽  
Expression In Escherichia Coli ◽  
Poly Ethylene

ABSTRACT The gene encoding a poly(dl-lactic acid) (PLA) depolymerase from Paenibacillus amylolyticus strain TB-13 was cloned and overexpressed in Escherichia coli. The purified recombinant PLA depolymerase, PlaA, exhibited degradation activities toward various biodegradable polyesters, such as poly(butylene succinate), poly(butylene succinate-co-adipate), poly(ethylene succinate), and poly(ε-caprolactone), as well as PLA. The monomeric lactic acid was detected as the degradation product of PLA. The substrate specificity toward triglycerides and p-nitrophenyl esters indicated that PlaA is a type of lipase. The gene encoded 201 amino acid residues, including the conserved pentapeptide Ala-His-Ser-Met-Gly, present in the lipases of mesophilic Bacillus species. The identity of the amino acid sequence of PlaA with Bacillus lipases was no more than 45 to 50%, and some of its properties were different from those of these lipases.

scholarly journals Properties and Skin Compatibility of Films Based on Poly(Lactic Acid) (PLA) Bionanocomposites Incorporating Chitin Nanofibrils (CN)

2020 ◽  
Vol 11 (2) ◽  
pp. 21 ◽  
Author(s):  
Maria-Beatrice Coltelli ◽  
Laura Aliotta ◽  
Alessandro Vannozzi ◽  
Pierfrancesco Morganti ◽  
Luca Panariello ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Calcium Carbonate ◽  
Chain Scission ◽  
Poly Lactic Acid ◽  
Butylene Succinate ◽  
Agar Diffusion Test ◽  
Wide Range ◽  
Poly Ethylene ◽  
Skin Compatibility ◽  
Die Extrusion

Nanobiocomposites suitable for preparing skin compatible films by flat die extrusion were prepared by using plasticized poly(lactic acid) (PLA), poly(butylene succinate-co-adipate) (PBSA), and Chitin nanofibrils as functional filler. Chitin nanofibrils (CNs) were dispersed in the blends thanks to the preparation of pre-nanocomposites containing poly(ethylene glycol). Thanks to the use of a melt strength enhancer (Plastistrength) and calcium carbonate, the processability and thermal properties of bionanocomposites films containing CNs could be tuned in a wide range. Moreover, the resultant films were flexible and highly resistant. The addition of CNs in the presence of starch proved not advantageous because of an extensive chain scission resulting in low values of melt viscosity. The films containing CNs or CNs and calcium carbonate resulted biocompatible and enabled the production of cells defensins, acting as indirect anti-microbial. Nevertheless, tests made with Staphylococcus aureus and Enterobacter spp. (Gram positive and negative respectively) by the qualitative agar diffusion test did not show any direct anti-microbial activity of the films. The results are explained considering the morphology of the film and the different mechanisms of direct and indirect anti-microbial action generated by the nanobiocomposite based films.

scholarly journals Recycling of Mixed Poly(Ethylene-terephthalate) and Poly(Lactic Acid)

2019 ◽  
Vol 253 ◽  
pp. 02005
Author(s):  
Daniel Gere ◽  
Tibor Czigany
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Lactic Acid ◽  
Impact Strength ◽  
Ethylene Terephthalate ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Thermal Stability Of

Nowadays, PLA is increasingly used as a packaging material, therefore it may appear in the petrol-based polymer waste stream. However, with the today’s mechanical recycling technologies PLA and PET bottles cannot be easily or cheaply separated. Therefore, our goal was to investigate the mechanical, morphological and thermal properties of different PET and PLA compounds in a wide range of compositions. We made different compounds from poly(ethylene-terephthalate) (PET) and poly(lactic acid) (PLA) by extrusion, and injection molded specimens from the compounds. We investigated the mechanical properties and the phase morphology of the samples and the thermal stability of the regranulates. PET and PLA are thermodynamically immiscible, therefore we observed a typical island-sea type morphology in SEM micrographs. When PLA was added, the mechanical properties (tensile strength, modulus, elongation at break and impact strength) changed significantly. The Young’s modulus increased, while elongation at break and impact strength decreased with the increase of the weight fraction of PLA. The TGA results indicated that the incorporation of PLA decreased the thermal stability of the PET/PLA blends.

scholarly journals Production of Eco-Sustainable Materials: Compatibilizing Action in Poly (Lactic Acid)/High-Density Biopolyethylene Bioblends

2021 ◽  
Vol 13 (21) ◽  
pp. 12157
Author(s):  
Eduardo da Silva Barbosa Ferreira ◽  
Carlos Bruno Barreto Luna ◽  
Danilo Diniz Siqueira ◽  
Edson Antonio dos Santos Filho ◽  
Edcleide Maria Araújo ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Maleic Anhydride ◽  
Impact Strength ◽  
High Density ◽  
Morphological Properties ◽  
Degree Of Crystallinity ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Additional Influence ◽  
Poly Ethylene

Motivated by environment preservation, the increased use of eco-friendly materials such as biodegradable polymers and biopolymers has raised the interest of researchers and the polymer industry. In this approach, this work aimed to produce bioblends using poly (lactic acid) (PLA) and high-density biopolyethylene (BioPE); due to the low compatibility between these polymers, this work evaluated the additional influence of the compatibilizing agents: poly (ethylene octene) and ethylene elastomer grafted with glycidyl methacrylate (POE-g-GMA and EE-g-GMA, respectively), polyethylene grafted with maleic anhydride (PE-g-MA), polyethylene grafted with acrylic acid (PE-g-AA) and the block copolymer styrene (ethylene-butylene)-styrene grafted with maleic anhydride (SEBS-g-MA) to the thermal, mechanical, thermomechanical, wettability and morphological properties of PLA/BioPE. Upon the compatibilizing agents’ addition, there was an increase in the degree of crystallinity observed by DSC (2.3–7.6% related to PLA), in the thermal stability as verified by TG (6–15 °C for TD10%, 6–11 °C TD50% and 112–121 °C for TD99.9% compared to PLA) and in the mechanical properties such as elongation at break (with more expressive values for the addition of POE-g-GMA and SEBS-g-MA, 9 and 10%, respectively), tensile strength (6–19% increase compared to PLA/BioPE bioblend) and a significant increase in impact strength, with evidence of plastic deformation as observed through SEM, promoted by the PLA/ BioPE phases improvement. Based on the gathered data, the added compatibilizers provided higher performing PLA/BioPE. The POE-g-GMA compatibilizer was considered to provide the best properties in relation to the PLA/BioPE bioblend, as well as the PLA matrix, mainly in relation to impact strength, with an increase of approximately 133 and 100% in relation to PLA and PLA/BioPE bioblend, respectively. Therefore, new ecological materials can be manufactured, aiming at benefits for the environment and society, contributing to sustainable development and stimulating the consumption of eco-products.

Sign in / Sign up

Export Citation Format

Share Document