scholarly journals Study of the Physical and Mechanical Properties of Thermoplastic Starch/Poly(Lactic Acid) Blends Modified with Acid Agents

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 578
Author(s):  
Carolina Caicedo ◽  
Heidy Lorena Calambás Pulgarin
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Organic Acids ◽  
Physical And Mechanical Properties ◽  
Thermoplastic Starch ◽  
Poly Lactic Acid ◽  
Thermal Transitions ◽  
Surface Polarity ◽  
Acid Agent ◽  
Structural Affinity

In this work, we present a functionalization strategy of starch-poly(lactic acid) (PLA) blends with organic acids. Lactic and acetic acid were used as acid agents, and oleic acid was also included in the previous acids, with the aim of finding a synergy that thermodynamically benefits the products and provides hydrophobicity. The ratio of starch and sorbitol was 70:30, and the added acid agent replaced 6% of the plasticizer; meanwhile, the thermoplastic starch (TPS)–PLA blend proportion was 70:30 considering the modified TPS. The mixtures were obtained in a torque rheometer at 50 rpm for 10 min at 150 °C. The organic acids facilitated interactions between TPS and PLA. Although TPS and PLA are not miscible, PLA uniformly dispersed into the starch matrix. Furthermore, a reduction in the surface polarity was achieved, which enabled the wettability to reach values close to those of neat PLA (TPS–L-PLA increased by 55% compared to TPS–PLA). The rheological results showed a modulus similar to that of TPS. In general, there were transitions from elastic to viscous, in which the viscous phase predominated. The first and second-order thermal transitions did not show significant changes. The structural affinity of lactic acid with biopolymers (TPS–L-PLA) allowed a greater interaction and was corroborated with the mechanical properties, resulting in a greater resistance with respect to pure TPS and blended TPS–PLA (28.9%). These results are particularly relevant for the packaging industry.

Short Review: Potential Production of Acacia Wood and its Biocomposites

2018 ◽  
Vol 917 ◽  
pp. 37-41 ◽  
Author(s):  
Muhammad Khusairy bin Bakri ◽  
Elammaran Jayamani ◽  
Soon Kok Heng ◽  
Akshay Kakar
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Review Paper ◽  
Natural Fiber ◽  
Physical And Mechanical Properties ◽  
Short Review ◽  
Fiber Composites ◽  
Poly Lactic Acid ◽  
Hybrid Polymer ◽  
Potential Production

In this short review paper, the physical and mechanical properties of acacia wood, poly lactic acid (PLA) and polyhydroxyalkanoates (PHA) were analyzed. Existing factors that affect the mechanical properties of natural fiber composites were investigated and identified. By knowing these factors, a possibility and potentiality in implementing the natural acacia wood reinforced material with hybrid polymer were discussed. It was found that the acacia wood had the potential to re-condition soil and have the potential to become reinforced materials in hybrid polymer composites. In addition, using fully biodegradable polymer such as PLA and PHA made it sustainable and environmentally friendly.

Effect of surface treatment on the physical and mechanical properties of injection molded poly(lactic acid)‐coir fiber biocomposites

2018 ◽  
Vol 40 (6) ◽  
pp. 2132-2141 ◽  
Author(s):  
M.E. González‐López ◽  
A.A. Pérez‐Fonseca ◽  
R. Manríquez‐González ◽  
M. Arellano ◽  
D. Rodrigue ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Surface Treatment ◽  
Physical And Mechanical Properties ◽  
Poly Lactic Acid ◽  
Coir Fiber ◽  
Injection Molded ◽  
Effect Of Surface

Mechanical Properties of Poly(lactic acid) / Thermoplastic Starch Blends Crosslinked by Gamma Radiation

2013 ◽  
Vol 781-784 ◽  
pp. 467-470 ◽  
Author(s):  
Siriruck Kalapakdee ◽  
Thirawudh Pongprayoon ◽  
Kasinee Hemvichian ◽  
Phiriyatorn Suwanmala ◽  
Wararat Kangsumrith
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Gamma Radiation ◽  
Crosslinking Agent ◽  
Thermoplastic Starch ◽  
Poly Lactic Acid ◽  
Optimum Dose ◽  
Gel Fraction ◽  
Twin Screw ◽  
Starch Blends

This research aims to determine the influences of radiation-induced crosslinking on the mechanical properties of polymer blends between poly (lactic acid) (PLA) and thermoplastic starch (TPS). PLA and TPS were mixed at different ratios (90:10, 80:20, 70:30, 60:40) in the presence of a crosslinking agent using a twin screw extruder. The blends were compression molded into films. The film samples were irradiated by gamma radiation at different doses. Gel fraction was used to determine crosslinking efficiency. Results showed that gamma radiation was able to induce crosslinking for PLA/TPS blends. The gel fraction and mechanical properties decreased with increasing TPS content. The optimum ratio of PLA:TPS with the maximum gel fraction and mechanical properties was 90:10 and the optimum dose was 40 kGy by gamma radiation.

scholarly journals Mechanical Properties of Starch and Poly(lactic acid) Biodegradable Sheets Added of Carboxylic Acids

2014 ◽  
Vol 5 (2) ◽  
pp. 26
Author(s):  
Marianne Ayumi Shirai ◽  
Juliano Zanela ◽  
Fabio Yamashita
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Citric Acid ◽  
Relative Humidity ◽  
Carboxylic Acids ◽  
Thermoplastic Starch ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Biodegradable Packaging ◽  
Hydrophobic Nature

<p><em>Thermoplastic starch and poly(lactic acid) (PLA) blends have been studied as potential materials for the production of biodegradable packaging. However due to the hydrophilic characteristic of starch and hydrophobic nature of PLA, these polymers are incompatible at microscopic level and this fact interfere significantly in the mechanical properties of the obtained materials. Several compatibilizer have been investigated to improve the compatibility between these polymers, including carboxylic acids. Thus, this study evaluated the mechanical properties of thermoplastic starch and PLA sheets added of citric and adipic acids produced by flat extrusion (calendaring-extrusion) and stored at different relative humidity. The sheets containing citric acid were thinner, more resistant and showed higher values of elongation at break. The relative humidity of storage interfered significantly in the mechanical properties, possibly due to the plasticizing effect of water. Citric acid was an additive which improved the mechanical properties of the starch and PLA sheets produced by flat extrusion. Furthermore, it is important to control the relative humidity of storage to not alter the mechanical properties of the starch based blends.</em></p><p>DOI: 10.14685/rebrapa.v5i2.164</p><p><em><br /></em></p>

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