scholarly journals Poly(l-Lactic Acid)/Pine Wood Bio-Based Composites

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3776
Author(s):  
Monika Dobrzyńska-Mizera ◽  
Monika Knitter ◽  
Aneta Woźniak-Braszak ◽  
Mikołaj Baranowski ◽  
Tomasz Sterzyński ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Interfacial Adhesion ◽  
Impact Resistance ◽  
Crystallization Rate ◽  
Polymer Chains ◽  
Pine Wood ◽  
Crystal Fraction ◽  
Wood Particles ◽  
Thermal Stability Of

Bio-based composites made of poly(l-lactic acid) (PLLA) and pine wood were prepared by melt extrusion. The composites were compatibilized by impregnation of wood with γ-aminopropyltriethoxysilane (APE). Comparison with non-compatibilized formulation revealed that APE is an efficient compatibilizer for PLLA/wood composites. Pine wood particles dispersed within PLLA act as nucleating agents able to start the growth of PLLA crystals, resulting in a faster crystallization rate and increased crystal fraction. Moreover, the composites have a slightly lower thermal stability compared to PLLA, proportional to filler content, due to the lower thermal stability of wood. Molecular dynamics was investigated using the solid-state 1H NMR technique, which revealed restrictions in the mobility of polymer chains upon the addition of wood, as well as enhanced interfacial adhesion between the filler and matrix in the composites compatibilized with APE. The enhanced interfacial adhesion in silane-treated composites was also proved by scanning electron microscopy and resulted in slightly improved deformability and impact resistance of the composites.

scholarly journals Nonisothermal Cold Crystallization Kinetics of Poly(lactic acid)/Bacterial Poly(hydroxyoctanoate) (PHO)/Talc

2019 ◽  
Vol 17 (1) ◽  
pp. 1266-1278
Author(s):  
Omaima Alhaddad ◽  
Safaa H. El-Taweel ◽  
Yasser Elbahloul
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Crystallization Kinetics ◽  
Crystallization Rate ◽  
Cold Crystallization ◽  
Poly Lactic Acid ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Kinetics Of ◽  
Thermal Stability Of

AbstractThe effects of bacterial poly(hydroxyoctanoate) (PHO) and talc on the nonisothermal cold crystallization behaviours of poly(lactic acid) (PLA) were analysed with differential scanning calorimetry (DSC), and the thermal stability of the samples was observed with thermal gravimetric analysis (TGA). The modified Avrami’s model was used to describe the nonisothermal cold crystallization kinetics of neat PLA and its blends. The activation energies E for nonisothermal cold crystallization were calculated by the isoconversional method of Kissinger-Akahira-Sunose (KAS). The DSC results showed that the PLA/PHO blends were immiscible in the whole studied range, and as the PHO and talc content increased, the crystallization rate of PLA accelerated, and the crystallinity of PLA in the PLA samples increased. The values of the Avrami exponent indicated that the nonisothermal cold crystallization of the neat PLA and its blends exhibited heterogeneous, three-dimensional spherulitic growth. The E values were strongly dependent on PHO and talc. The TGA results showed that the presence of PHO and talc slightly influenced the thermal stability of PLA.

Properties of HDPE/Clay/Wood Nanocomposites

2007 ◽  
Author(s):  
Q. Wu ◽  
Y. Lei ◽  
F. Yao ◽  
Y. Xu ◽  
K. Lian
Keyword(s):  
Thermal Stability ◽  
Tensile Elongation ◽  
Tensile Modulus ◽  
Crystallization Rate ◽  
Clay Content ◽  
Melt Compounding ◽  
Storage And Loss Moduli ◽  
Organic Clay ◽  
The Impact ◽  
Thermal Stability Of

Composites based on high density polyethylene (HDPE), pine flour, and organic clay were made by melt compounding and injection molding. The influence of clay on crystallization behavior, mechanical properties, water absorption, and thermal stability of HDPE/pine composites were investigated. The HDPE/pine composites containing exfoliated clay were made by a two-step melt compounding procedure with a maleated polyethylene (MAPE) as a compatibilizer. Adding 2% clay to a HDPE/pine composite without MAPE decreased the crystallization temperature (Tc) and rate, and the crystallinity level. When 2% MAPE was added, the Tc and crystallization rate increased, but the crystallinity level was lowered. The flexural strength and the tensile strength of HDPE/pine composites increased 19.6% and 24.2% respectively with addition of 1% clay but then decreased slightly as the clay content was increased to 3%. The tensile modulus and tensile elongation were increased 11.8% and 13% respectively with addition of 1% clay but the storage and loss moduli barely change as the clay content was increased to 3%. The impact strength was lowered 7.5% by adding 1% clay, but did not decrease further as more clay was added. The moisture content and thickness swelling of the HDPE/pine composites was reduced by the clay, but did not improve the thermal stability.

The Mechanical Characteristics of Straw/poly(Lactic Acid) Composite Materials

2011 ◽  
Vol 335-336 ◽  
pp. 153-156
Author(s):  
Xue Li Wu ◽  
Jian Hui Qiu ◽  
Lin Lei ◽  
Yang Zhao ◽  
Eiichi Sakai
Keyword(s):  
Thermal Stability ◽  
Grain Size ◽  
Lactic Acid ◽  
Mechanical Characteristics ◽  
Fracture Strain ◽  
Filler Content ◽  
Agricultural Wastes ◽  
Poly Lactic Acid ◽  
Effective Utilization ◽  
Thermal Stability Of

To consider the effective utilization of plastics and agricultural wastes, rice straw fibre was extracted from agricultural wastes, and then composited with polylactic acid(PLA). The thermal stability of straw/poly(lactic acid)(straw/PLA) composites decreased (Thermogravimetric Analysis, TGA). Tensile strength, fracture strain and sharply impact strength of straw/PLA were decreased with the increase of filler content and grain size of straw. Yong’s modulus were increased as the increasing of straw content.

Morphology, Mechanical and Thermal Properties of Poly(Lactic Acid)/Propylene-Ethylene Copolymer/Cellulose Composites

2019 ◽  
Vol 972 ◽  
pp. 172-177
Author(s):  
Sirirat Wacharawichanant ◽  
Patteera Opasakornwong ◽  
Ratchadakorn Poohoi ◽  
Manop Phankokkruad
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Tensile Stress ◽  
Cellulose Fibers ◽  
Phase Morphology ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Ethylene Copolymer ◽  
Thermal Stability Of

This work studied the effects of various types of cellulose fibers on the morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC) (90/10 w/w) blends. The PLA/PEC blends before and after adding cellulose fibers were prepared by melt blending method in the internal mixer and molded by compression method. The morphological analysis observed that the presence of cellulose in PLA did not change the phase morphology of PLA, and PLA/cellulose composite surfaces were observed the cellulose fibers inserted in PLA matrix and fiber pull-out. The phase morphology of PLA/PEC blends was changed from brittle fracture to ductile fracture behavior and showed the phase separation between PLA and PEC phases. The presence of celluloses did not improve the compatibility between PLA and PEC phases. The tensile stress and strain curves found that the tensile stress of PLA was the highest value. The addition of all celluloses increased Young’s modulus of PLA. The PEC presence increased the tensile strain of PLA over two times when compared with neat PLA and PLA was toughened by PEC. The incorporation of cellulose fibers in PLA/PEC blends could improve Young’s modulus, tensile strength, and stress at break of the blends. The thermal stability showed that the degradation temperatures of all types of cellulose were less than the degradation temperatures of PLA. Thus, the incorporation of cellulose in PLA could not enhance the thermal stability of PLA composites and PLA/PEC composites. The degradation temperature of PEC was the highest value, but it could not improve the thermal stability of PLA. The incorporation of cellulose fibers had no effect on the melting temperature of the PLA blend and composites.

scholarly journals Multifunctional PLA Blends Containing Chitosan Mediated Silver Nanoparticles: Thermal, Mechanical, Antibacterial, and Degradation Properties

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 22 ◽  
Author(s):  
Agueda Sonseca ◽  
Salim Madani ◽  
Gema Rodríguez ◽  
Víctor Hevilla ◽  
Coro Echeverría ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Silver Nanoparticles ◽  
Lactic Acid ◽  
Food Packaging ◽  
Synthesis Method ◽  
Crystallization Rate ◽  
Poly Lactic Acid ◽  
Scanning Calorimetry ◽  
The Matrix ◽  
Degradation Properties

Poly(lactic acid) (PLA) is one of the most commonly employed synthetic biopolymers for facing plastic waste problems. Despite its numerous strengths, its inherent brittleness, low toughness, and thermal stability, as well as a relatively slow crystallization rate represent some limiting properties when packaging is its final intended application. In the present work, silver nanoparticles obtained from a facile and green synthesis method, mediated with chitosan as a reducing and stabilizing agent, have been introduced in the oligomeric lactic acid (OLA) plasticized PLA in order to obtain nanocomposites with enhanced properties to find potential application as antibacterial food packaging materials. In this way, the green character of the matrix and plasticizer was preserved by using an eco-friendly synthesis protocol of the nanofiller. The X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results proved the modification of the crystalline structure as well as the crystallinity of the pristine matrix when chitosan mediated silver nanoparticles (AgCH-NPs) were present. The final effect over the thermal stability, mechanical properties, degradation under composting conditions, and antimicrobial behavior when AgCH-NPs were added to the neat plasticized PLA matrix was also investigated. The obtained results revealed interesting properties of the final nanocomposites to be applied as materials for the targeted application.

Morphology and Properties of Poly(Lactic Acid)/Ethylene-Octene Copolymer Blends with Different Organoclay Types

2020 ◽  
Vol 837 ◽  
pp. 174-180
Author(s):  
Sirirat Wacharawichanant ◽  
Attachai Sriwattana ◽  
Kulaya Yaisoon ◽  
Manop Phankokkruad
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Two Phase ◽  
Copolymer Blends ◽  
Ethylene Octene Copolymer ◽  
Surface Modified ◽  
Thermal Stability Of ◽  
Observation Results

This work studied the morphology, mechanical and thermal properties of poly (lactic acid) (PLA)/ethylene-octene copolymer (EOC) (80/20) blends with different organoclay types. Herein, EOC was introduced to toughening PLA by melt blending and organoclay was used to improve compatibility and tensile properties of the blends. The two organoclay types were nanoclay surface modified with aminopropyltriethoxysilane 0.5-5 wt% and octadecylamine 15-35% (Clay-ASO) and nanoclay surface modified with dimethyl dialkyl (C14-C18) amine 35-45 wt% (Clay-DDA). The organoclay contents were 3, 5 and 7 phr. Scanning electron microscope (SEM) observation results revealed PLA/EOC blends demonstrated a two-phase separation of dispersed EOC phase and PLA matrix phase. The addition of organoclay significantly improved the compatibility between PLA and EOC phases due to EOC droplet size decreased dominantly in PLA matrix, so organoclay could act as an effective compatibilizer. The incorporation of organoclay increased significantly tensile strength of PLA/EOC/organoclay composites while Young’s modulus increased with 5 phr of organoclay. The thermal stability of PLA/EOC blends did not change when compared with neat PLA, and when added Clay-ASO in the blends could improve the thermal stability of the PLA/EOC blends.

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