scholarly journals Mechanical Properties and Bioactivity of Poly(Lactic Acid) Composites Containing Poly(Glycolic Acid) Fiber and Hydroxyapatite Particles

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 249
Author(s):  
Han-Seung Ko ◽  
Sangwoon Lee ◽  
Doyoung Lee ◽  
Jae Young Jho
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Flexural Strength ◽  
Interfacial Adhesion ◽  
Glycolic Acid ◽  
Compact Bone ◽  
Poly Lactic Acid ◽  
Coupling Reactions ◽  
The Poor ◽  
Human Compact Bone

To enhance the mechanical strength and bioactivity of poly(lactic acid) (PLA) to the level that can be used as a material for spinal implants, poly(glycolic acid) (PGA) fibers and hydroxyapatite (HA) were introduced as fillers to PLA composites. To improve the poor interface between HA and PLA, HA was grafted by PLA to form HA-g-PLA through coupling reactions, and mixed with PLA. The size of the HA particles in the PLA matrix was observed to be reduced from several micrometers to sub-micrometer by grafting PLA onto HA. The tensile and flexural strength of PLA/HA-g-PLA composites were increased compared with those of PLA/HA, apparently due to the better dispersion of HA and stronger interfacial adhesion between the HA and PLA matrix. We also examined the effects of the length and frequency of grafted PLA chains on the tensile strength of the composites. By the addition of unidirectionally aligned PGA fibers, the flexural strength of the composites was greatly improved to a level comparable with human compact bone. In the bioactivity tests, the growth of apatite on the surface was fastest and most uniform in the PLA/PGA fiber/HA-g-PLA composite.

Composites of Poly(lactic Acid) with Rice Straw Fibers Modified by Poly(butyl Acrylate)

2011 ◽  
Vol 675-677 ◽  
pp. 357-360
Author(s):  
Li Jun Qin ◽  
Jian Hui Qiu ◽  
Ming Zhu Liu ◽  
Sheng Long Ding ◽  
Liang Shao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Rice Straw ◽  
Butyl Acrylate ◽  
Interfacial Adhesion ◽  
Suspension Polymerization ◽  
Water Solution ◽  
Poly Lactic Acid ◽  
Biodegradable Composites

The modified rice straw fibers (MRSF) were prepared by suspension polymerization technique of butyl acrylate (BA) monomer and rice straw fibers (RSF) in water solution. FTIR test indicated that PBA was coated and absorbed on RSF.The biodegradable composites were prepared with the MRSF and poly(lactic acid) (PLA) by HAAKE rheometer. Mechanical properties showed that the tensile strength of PLA/MRSF composites were (W (%) =7.98%) increased by 6 MPa compared with blank sample. The possible reason was that the good interfacial adhesion between PLA and MRSF, which was demonstrated by SEM.

Improving mechanical properties of ramie/poly (lactic acid) composites by synergistic effect of fabric cyclic loading and alkali treatment

2016 ◽  
Vol 47 (3) ◽  
pp. 390-407 ◽  
Author(s):  
Jianxia Yang ◽  
Luping Zhu ◽  
Zhuo Yang ◽  
Lan Yao ◽  
Yiping Qiu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Lactic Acid ◽  
Cyclic Loading ◽  
Synergistic Effect ◽  
Interfacial Adhesion ◽  
Alkali Treatment ◽  
Flexural Modulus ◽  
Poly Lactic Acid ◽  
Orientation Factor

Natural cellulose fiber reinforced biopolymer composites have attracted increasing attention due to environmental concerns. However, these fibers have relatively low mechanical properties and poor interfacial adhesion with matrices, limiting their composite mechanical properties. This study investigates the synergistic effect of two recently developed techniques to maximize the mechanical performance of ramie/poly (lactic acid) laminated composites, namely alkali treatment to loosen fiber molecular structure and to increase fiber surface roughness and subsequent cyclic loading treatment to fabrics to increase their tensile strength and modulus. The results show that the treated fabrics have increased crystallinity and crystal orientation factor as well as better orientation of fibers and more uniform structures, leading to 11% improvement in fabric tensile strength and 57% enhancement of tensile strength (90.9 MPa), 48% higher tensile modulus (5.6 GPa), 18% higher flexural strength (149.4 MPa), and 91% higher flexural modulus (8.2 GPa) for the corresponding composites. Meanwhile, postmortem analysis shows that better interfacial adhesion is achieved using this approach.

Physiochemical, optical and mechanical properties of poly(lactic acid) nanocomposites filled with toluene diisocyanate grafted cellulose nanocrystals

RSC Advances ◽  
2016 ◽  
Vol 6 (12) ◽  
pp. 9438-9445 ◽  
Author(s):  
Jae-Gyoung Gwon ◽  
Hye-Jung Cho ◽  
Sang-Jin Chun ◽  
Soo Lee ◽  
Qinglin Wu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Cellulose Nanocrystals ◽  
Toluene Diisocyanate ◽  
Poly Lactic Acid ◽  
Hydrophilic Surface ◽  
The Poor ◽  
Solvent Systems ◽  
Optical And Mechanical Properties ◽  
Surface Nature

Although cellulose nanocrystals (CNCs) have been highlighted as a potential nano-reinforcement in polymer composites, the hydrophilic surface nature of CNCs limits their usage in the composite area due to the poor dispersibility of the CNCs in nonpolar solvent systems.

Effect of Matrix–Particle Interfacial Adhesion on the Mechanical Properties of Poly(lactic acid)/Wood-Flour Micro-Composites

2009 ◽  
Vol 17 (2) ◽  
pp. 83-94 ◽  
Author(s):  
Eustathios Petinakis ◽  
Long Yu ◽  
Graham Edward ◽  
Katherine Dean ◽  
Hongsheng Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Interfacial Adhesion ◽  
Wood Flour ◽  
Poly Lactic Acid

scholarly journals Analysis, Development, and Scaling-Up of Poly(lactic acid) (PLA) Biocomposites with Hazelnuts Shell Powder (HSP)

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4080
Author(s):  
Laura Aliotta ◽  
Alessandro Vannozzi ◽  
Daniele Bonacchi ◽  
Maria-Beatrice Coltelli ◽  
Andrea Lazzeri
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Interfacial Adhesion ◽  
Scale Up ◽  
Analytical Models ◽  
Poly Lactic Acid ◽  
Residual Moisture ◽  
The Matrix ◽  
Shell Powder

In this work, two different typologies of hazelnuts shell powders (HSPs) having different granulometric distributions were melt-compounded into poly(lactic acid) (PLA) matrix. Different HSPs concentration (from 20 up to 40 wt.%) were investigated with the aim to obtain final biocomposites with a high filler quantity, acceptable mechanical properties, and good melt fluidity in order to be processable. For the best composition, the scale-up in a semi-industrial extruder was then explored. Good results were achieved for the scaled-up composites; in fact, thanks to the extruder venting system, the residual moisture is efficiently removed, guaranteeing to the final composites improved mechanical and melt fluidity properties, when compared to the lab-scaled composites. Analytical models were also adopted to predict the trend of mechanical properties (in particular, tensile strength), also considering the effect of HSPs sizes and the role of the interfacial adhesion between the fillers and the matrix.

scholarly journals Biocomposites based on poly(lactic acid) and kenaf fibers: Effect of micro-fibrillated cellulose

2013 ◽  
Vol 32 (1) ◽  
pp. 331 ◽  
Author(s):  
Gordana Bogoeva-Gaceva ◽  
Dimko Dimeski ◽  
Vineta Srebrenkoska
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Flexural Strength ◽  
Microfibrillated Cellulose ◽  
Poly Lactic Acid ◽  
Kenaf Fiber ◽  
Kenaf Fibers

In this work, the influence of microfibrillated cellulose (MFC) on the basic mechanical properties of PLA/kenaf fiber biocomposites has been studied. The addition of 5–15 % microfibrillated cellulose to a biocomposite premix has resulted in an increased glass transition temperature of the final product, produced by compression molding of previously melt-mixed composite components. The presence of MFC has influenced the interface-sensitive properties of the PLA/kenaf composite: at an optimal loading of 10 %, the interfacial energy release rate was increased by about 20 %. Moreover, flexural strength and modulus of the composites were also improved (from 34.8 MPa to 57.1 MPa and from 4.9 GPa to 5.8 GPa, respectively).   

scholarly journals Poly(Lactic Acid) Filled with Cassava Starch-g-Soybean Oil Maleate

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Nopparut Kiangkitiwan ◽  
Kawee Srikulkit
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Soybean Oil ◽  
Interfacial Adhesion ◽  
Cassava Starch ◽  
Poly Lactic Acid ◽  
Starch Granules ◽  
Screw Extruder ◽  
Surface Appearance ◽  
Twin Screw

Poly(lactic acid), PLA, is a biodegradable polymer, but its applications are limited by its high cost and relatively poorer properties when compared to petroleum-based plastics. The addition of starch powder into PLA is one of the most promising efforts because starch is an abundant and cheap biopolymer. However, the challenge is the major problem associated with poor interfacial adhesion between the hydrophilic starch granules and the hydrophobic PLA, leading to poorer mechanical properties. In this paper, soybean oil maleate (SOMA) was synthesized by grafting soybean oil with various weight percents of maleic anhydride (MA) using dicumyl peroxide (DCP) as an initiator. Then, SOMA was employed for the surface modifying of cassava starch powder, resulting in SOMA-g-STARCH. The obtained SOMA-g-STARCH was mixed with PLA in various weight ratios using twin-screw extruder, resulting in PLA/SOMA-g-STARCH. Finally, the obtained PLA/SOMA-g-STARCH composites were prepared by a compression molding machines. The compatibility, thermal properties, morphology properties, and mechanical properties were characterized and evaluated. The results showed that the compatibility, surface appearance, and mechanical properties at 90 : 10 and 80 : 20 ratios of PLA/SOMA-g-STARCH were the best.

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