The morphology, physical, and mechanical properties of poly (lactic acid)-based wood flour and pulp fiber biocomposites

Author(s):  
Saeid Reza Farrokhpayam ◽  
Milad Asadi Shahabi ◽  
Babak Nosrati Sheshkal ◽  
Rahim Mohebbi Gargari
Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 204 ◽  
Author(s):  
Ru Liu ◽  
Xiaoqian Yin ◽  
Anmin Huang ◽  
Chen Wang ◽  
Erni Ma

In this study, poly(lactic acid) (PLA)/wood flour (WF) composites were prepared by first blending PLA with organo-montmorillonite (OMMT) at different contents (0.5, 1, 1.5, and 2 wt %). The physical and mechanical properties of the virgin and OMMT modified PLA and its WF composites were tested. The results showed that: (1) at low OMMT content (<1 wt %), OMMT can uniformly disperse into the PLA matrix with highly exfoliated structures. When the content increased to 1.5 wt %, some aggregations occurred; (2) after a second extruding process, the aggregated OMMT redistributed into PLA and part of OMMT even penetrated into the WF cell wall. However, at the highest OMMT content (2 wt %), aggregates still existed; (3) the highly exfoliated OMMT was beneficial to the physical and mechanical properties of PLA and the WF composites. The optimal group of OMMT-modified PLA was found at an OMMT content of 0.5 wt %, while for the PLA/WF system, the best properties were achieved at an OMMT content of 1.5 wt %.


Holzforschung ◽  
2016 ◽  
Vol 70 (5) ◽  
pp. 439-447 ◽  
Author(s):  
Ru Liu ◽  
Shupin Luo ◽  
Jinzhen Cao ◽  
Yu Chen

Abstract Wood flour/polylactic acid (WF/PLA) composites were produced with a WF content of 50% based on three types of waterborne polyacrylate (PA) emulsions including a PA homopolymer emulsion and two types of silane-PA copolymer emulsions as coupling agents. Two silanes were in focus, namely, γ-methacryloxypropyl- trimethoxysilane (silane-1) and vinyltrimethoxysilane (silane-2). The emulsions and the modified WFs were characterized, and the effects were investigated in terms of emulsion type and their loading levels on the mechanical properties of WF/PLA composites. (1) Both types of silanes could be successfully copolymerized with PA to form stable emulsions. (2) With increasing PA loading, the mechanical properties (except for flexural modulus) of the composites increased at first before reaching the maximum values at 4% PA loading and then the properties worsened. However, these values were larger than those of pure composites, especially in cases when PA-silane emulsions were applied. (3) PA modified with silane-1 showed the best coupling effect among all the three PA emulsions. The results can be interpreted that PA emulsions are effective coupling agents for the preparation of high-performance WPCs.


2018 ◽  
Vol 917 ◽  
pp. 37-41 ◽  
Author(s):  
Muhammad Khusairy bin Bakri ◽  
Elammaran Jayamani ◽  
Soon Kok Heng ◽  
Akshay Kakar

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.


2018 ◽  
Vol 40 (6) ◽  
pp. 2132-2141 ◽  
Author(s):  
M.E. González‐López ◽  
A.A. Pérez‐Fonseca ◽  
R. Manríquez‐González ◽  
M. Arellano ◽  
D. Rodrigue ◽  
...  

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 578
Author(s):  
Carolina Caicedo ◽  
Heidy Lorena Calambás Pulgarin

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.


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