Study of the Properties of Plasticised Poly(Lactic Acid) with Poly(1,3-Butylene Adipate)

2008 ◽  
Vol 16 (9) ◽  
pp. 597-604 ◽  
Author(s):  
Wang Ning ◽  
Zhang Xingxiang ◽  
Yu Jiugao ◽  
Fang Jianming
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Glass Transition ◽  
Renewable Resources ◽  
Migration Rate ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Thermally Induced ◽  
Migration Resistance ◽  
Area Of Application

Poly(lactic acid) (PLA) is a biodegradable thermoplastic that can be produced from renewable resources, and so was considered as a major alternative to petroleum-based plastics for packaging applications. However, plasticisation of PLA was required in order to obtain films with sufficient flexibility. Poly(1, 3-butylene adipate) (PBA) was used as a novel plasticiser for PLA, and acetyltributyl citrate (ATBC) was used as the control. FTIR revealed that interaction took place between PLA and plasticiser. With an increasing plasticiser content, storage modulus and glass transition temperature decreased, but elongation at break increased. The elongation at break of PBA-plasticised PLA (PBA content 30 wt.%) could be above 600%, higher than that of ATBC-plasticised PLA (ATBC content 30 wt.%). Moreover, PBA was able to restrain thermally induced migration of plasticiser in plasticised PLA. It was also found that the migration rate of ATBC was directly proportional to the ATBC content in the blends. The rheology showed that the plasticiser could obviously decrease the shear viscosity and improve the fluidity of the blends. PBA was therefore recognised as a novel plasticiser for enhancing the properties of PLA. In particular, as a biodegradable polymer, PBA, when used as a plasticiser in PLA, can enhance migration resistance for its proper molecular weight. Moreover, the area of application of plasticised PLA is broadened.

scholarly journals Investigation on compatibility of PLA/PBAT blends modified by epoxy-terminated branched polymers through chemical micro-crosslinking

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 39-54 ◽  
Author(s):  
Bo Wang ◽  
Yujuan Jin ◽  
Kai’er Kang ◽  
Nan Yang ◽  
Yunxuan Weng ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Sem Analysis ◽  
Branched Polymers ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Butylene Terephthalate ◽  
The Difference ◽  
Physical And Chemical ◽  
The Impact

AbstractIn this study, a type of epoxy-terminated branched polymer (ETBP) was used as an interface compati- bilizer to modify the poly lactic acid (PLA)/poly(butylene adipate-co-butylene terephthalate) (PBAT) (70/30) blends. Upon addition of ETBP, the difference in glass transition temperature between PLA and PBAT became smaller. By adding 3.0 phr of ETBP, the elongation at break of the PLA/PBAT blends was found increased from 45.8% to 272.0%; the impact strength increased from 26.2 kJ·m−2 to 45.3 kJ·m−2. In SEM analysis, it was observed that the size of the dispersed PBAT particle decreased with the increasing of ETBP content. These results indicated that the compatibility between PLA and PBAT can be effectively enhanced by using ETBP as the modifier. The modification mechanism was discussed in detail. It proposes that both physical and chemical micro-crosslinking were formed, the latter of which was confirmed by gel content analysis.

scholarly journals Effect of HNT on mechanical and thermal properties of poly(lactic acid)/polypropylene carbonate blends

Polimery ◽  
2021 ◽  
Vol 66 (9) ◽  
pp. 459-465
Author(s):  
Intan Najwa Humaira Mohamed Haneef ◽  
Yose Fachmi Buys ◽  
Norhashimah Mohd Shaffiar ◽  
Sharifah Imihezri Syed Shaharuddin ◽  
Abdul Malek Abdul Hamid ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Thermal Properties ◽  
Halloysite Nanotubes ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Melt Mixing ◽  
Elongation At Break ◽  
Young’S Moduli ◽  
Dsc Thermograms

In this work, the influence of halloysite nanotubes (HNTs) on the mechanical and thermal properties of the poly(lactic acid)/polypropylene carbonate (PLA/PPC 70/30) blend was studied. The HNT was incorporated into the PLA/PPC blend by melt mixing. It was found that addition of 2-6 wt % HNT successfully improved the tensile and flexural strength as well as the flexural and Young’s  moduli of PLA/PPC blend, due to the reinforcing effect. Although the elongation at break decreases with increasing HNT content, its value is much higher than that of pure PLA. Moreover, the addition of HNT didnot affect the miscibility of PLA and PPC, since two glass transition temperatures were observed in the DSC thermograms. However, a higher content of HNT may improve the compatibility between PLA and PPC as evidenced by the lower difference between the glass transition temperature of PPC and PLA and reduced crystallinity resulting in higher tensile strength of nanocomposites.Keywords: PLA, PPC, HNT, mechanical properties, thermal properties.

scholarly journals Este trabajo se centró en el desarrollo de envases activos biodegradables con mezclas de poli (ácido láctico) (PLA), poli (etileno-co-acetato de vinilo) (EVA), polietilenglicol (PEG) y quitosano (QUI). Se investigaron las características morfológicas térmicas y mecánicas de las mezclas, así como, al mismo tiempo, la actividad antifúngica del envase. Para evaluar la actividad antimicrobiana de las mezclas PLA/EVA/PEG/QUI, las muestras se insertaron entre rebanadas de pan sin conservantes para evaluar su vida útil. Al comparar entre PLA/EVA/PEG, mezclas de PLA/EVA/PEG/QUI y PLA puro fue posible evidenciar la miscibilidad parcial, la disminución de la temperatura de transición vítrea (Tg) al incorporar PEG en las mezclas, una disminución de la fuerza fl exural del 71% y módulo de elasticidad del 80,4% a la mezcla PLA/ EVA/PEG/2.5QUI, así como un aumento del alargamiento a la rotura del 153% y del 392% a la tenacidad al impacto. Se observó un comportamiento similar a PLA/EVA/20PEG y PLA/EVA/PEG/5.0QUI. La película que contiene QUI entre las rebanadas de pan también influyó en la reducción de la actividad del agua y redujo aproximadamente un 35% en el recuento de mohos y levaduras en las rebanadas de pan. El quitosano en mezclas con PLA/EVA/PEG mostró potencial como agente antifúngico natural en envases de panadería.  

2021 ◽  
Vol 10 (9) ◽  
pp. e50010916964
Author(s):  
Leticia Riboldi Cavalli ◽  
Jalma Maria Klein ◽  
Ivana Greice Sandri ◽  
Rosmary Brandalise
Keyword(s):  
Antimicrobial Activity ◽  
Lactic Acid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Elasticity Modulus ◽  
Morphological Characteristics ◽  
Poly Lactic Acid ◽  
Elongation At Break ◽  
Poly Ethylene

This work focused on the development of biodegradable active packaging with poly(lactic acid) (PLA), poly(ethylene-co-vinyl acetate) (EVA), polyethylene glycol (PEG) and chitosan (QUI) blends. It investigated thermal and mechanical morphological characteristics of the blends, as the same time, the antifungal activity of the packaging. To assess the antimicrobial activity of the PLA/EVA/PEG/QUI blends, the samples were inserted between slices of bread with no preservative to the evaluation of their shelf life. By comparing between PLA/EVA/PEG, PLA/EVA/PEG/QUI blends and neat PLA was possible to evidence the partial miscibility, decreased glass transition temperature (Tg) by incorporating PEG into the blends, a decrease in flexural strength of 71% and elasticity modulus of 80.4% to PLA/EVA/PEG/2.5QUI blend, as well as an increase in elongation at break of 153% and 392% to impact toughness. A similar behavior was observed to PLA/EVA/20PEG and PLA/EVA/PEG/5.0QUI. The QUI-containing film among the bread slices has also influenced the water activity reduction, and reduced about 35% in the count of molds and yeasts in the slices of bread. Chitosan in mixtures with PLA/EVA/PEG showed potential as a natural antifungal agent in bakery packaging.

scholarly journals Poly(lactic Acid): A Versatile Biobased Polymer for the Future with Multifunctional Properties—From Monomer Synthesis, Polymerization Techniques and Molecular Weight Increase to PLA Applications

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1822
Author(s):  
Evangelia Balla ◽  
Vasileios Daniilidis ◽  
Georgia Karlioti ◽  
Theocharis Kalamas ◽  
Myrika Stefanidou ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Plastic Pollution ◽  
Practical Applications ◽  
Decomposition Reactions ◽  
Melt Polycondensation ◽  
Polymerization Conditions ◽  
Molecular Weight Increase

Environmental problems, such as global warming and plastic pollution have forced researchers to investigate alternatives for conventional plastics. Poly(lactic acid) (PLA), one of the well-known eco-friendly biodegradables and biobased polyesters, has been studied extensively and is considered to be a promising substitute to petroleum-based polymers. This review gives an inclusive overview of the current research of lactic acid and lactide dimer techniques along with the production of PLA from its monomers. Melt polycondensation as well as ring opening polymerization techniques are discussed, and the effect of various catalysts and polymerization conditions is thoroughly presented. Reaction mechanisms are also reviewed. However, due to the competitive decomposition reactions, in the most cases low or medium molecular weight (MW) of PLA, not exceeding 20,000–50,000 g/mol, are prepared. For this reason, additional procedures such as solid state polycondensation (SSP) and chain extension (CE) reaching MW ranging from 80,000 up to 250,000 g/mol are extensively investigated here. Lastly, numerous practical applications of PLA in various fields of industry, technical challenges and limitations of PLA use as well as its future perspectives are also reported in this review.

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.

Tensile and water absorption properties of solvent cast biofilms of sugarcane leaves fibre-filled poly(lactic) acid

2018 ◽  
Vol 33 (3) ◽  
pp. 289-304 ◽  
Author(s):  
Kuhananthan Nanthakumar ◽  
Chan Ming Yeng ◽  
Koay Seong Chun
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Water Absorption ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Poly Lactic Acid ◽  
Infrared Analysis ◽  
Absorption Properties ◽  
Elongation At Break ◽  
Bleaching Treatment

This research covers the preparation of poly(lactic acid) (PLA)/sugarcane leaves fibre (SLF) biofilms via a solvent-casting method. The results showed that the tensile strength and Young’s modulus of PLA/SLF biofilms increased with the increasing of SLF content. Nevertheless, the elongation at break showed an opposite trend as compared to tensile strength and Young’s modulus of biofilms. Moreover, water absorption properties of PLA/SLF biofilms increased with the increasing of SLF content. In contrast, the tensile strength and Young’s modulus of biofilms were enhanced after bleaching treatment with hydrogen peroxide on SLF, but the elongation at break and water absorption properties of bleached biofilms were reduced due to the improvement of filler–matrix adhesion in biofilms. The tensile and water properties were further discussed using B-factor and Fick’s law, respectively. Furthermore, the functional groups of unbleached and bleached SLF were characterized by Fourier transform infrared analysis.

Effects of walnut shell powders on the morphology and the thermal and mechanical properties of poly(lactic acid)

2019 ◽  
Vol 33 (10) ◽  
pp. 1383-1395
Author(s):  
Hongjuan Zheng ◽  
Zhengqian Sun ◽  
Hongjuan Zhang
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Property Testing ◽  
Walnut Shell ◽  
Poly Lactic Acid ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Heat Distortion Temperature ◽  
Testing Techniques

Poly(lactic acid) (PLA) has good environmental compatibility, however, its high brittleness, slow rate of crystallization, and low heat distortion temperature restrict its widespread use. To overcome these limitations, in this study, PLA was mixed with walnut shell (WS) powders. The effects of WS powders on the morphology and the thermal and mechanical properties of PLA were investigated. The products were characterized by differential scanning calorimetry (DSC), infrared (IR) spectroscopy, polarizing optical microscopy (POM), and various mechanical property testing techniques. The results showed that WS powders had a significant effect on the morphology and the thermal and mechanical properties of PLA. The tensile strength, impact strength, and elongation at break of the PLA/WS composites first increased and then decreased with the increasing addition of WS powders. When the addition of WS powders was about 0.5 wt%, they reached maximum values of 51.2 MPa, 23.3 MPa, and 19.0%, respectively. Compared with neat PLA, the spherulite grain size of the composites could be reduced and many irregular polygons were formed during crystallization. The melting, cold crystallization, and glass-transition temperatures of the composites were lower than those of neat PLA.

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