Papers by Keyword: Polylactide (PLA)

Abstract: In this study, Fourier-transform infrared spectroscopy (FTIR) of polylactide (PLA) biocomposites reinforced with hemp fibers were analyzed. Three samples of biocomposites with different proportions of hemp fibers in the PLA matrix were compared. Hemp and PLA fibers in biocomposite were evenly blended using carding technology. Samples before and after water absorption were compared using scanning electron microscopy (SEM). Thermoset treated polylactide and hemp fiber biocomposites have high mechanical properties, that allow to reduce the number of materials in the product. The developed biocomposite can be used as a slab material and for molded parts of furniture, etc.

Abstract: Within the current report the first results of the upcoming multi-stage research cycle on the development of high-performance environmentally friendly PLA/PBAT blend based composite materials are presented. Development and basic characterization of PLA/PBAT blends at various wt.-to-wt. ratios of the base polymeric components is performed. Rheological properties of PLA and PBAT have been investigated by means of rotational viscometry to define the optimal blending parameters. PLA/PBAT blends have been obtained by using twin-screw extrusion. Structural features of the obtained polymer blend compositions have been revealed by means of Fourier transform infrared spectroscopy. Crystallization behavior of the obtained polymer blend compositions have been characterized by means of differential scanning calorimetry. Thermal stability of the obtained polymer blend compositions has been studied by using thermogravimetric analysis. Mechanical behavior of the obtained polymer blend compositions has been studied by means of both quasistatic (in respects to tensile and flexural properties) and dynamic tests (impact resistance).

Abstract: Polymeric material, which is commonly used in packaging, has been widely applied due to the fact that it is lightweight and chemical resistant. Being non-degradable, polymeric waste can thus only be eliminated by burning, and subsequently, there is a rising need for degradable polymeric material to manage this manner of disposal. This study thus uses degradable, low-melting-point polylactide (LMPLA) fibers and recycled polyester (RPET) fibers to make nonwoven fabrics for packaging. The tensile strength, tear strength, and air permeability of the nonwoven fabrics are then tested. The experiment results show that a 40% of RPET fibers can effectively promote the mechanical properties of the LMPLA nonwoven fabrics.

Abstract: Calcium phosphate bone cement (CPC), a bioceramic, is commonly used in artificial bone scaffold for impaired bones. In this study, CPC is mixed with polylactide (PLA) fibers and porogenic agent to form CPC/PLA composite bone scaffold. The compressive strength of the resulting bone scaffolds is evaluated and the fractured cross-section is observed by a scanning electron microscope (SEM), thereby determining the influence of fiber length. The experimental results show that the shorter the fiber is, the greater the compressive strength is.

Abstract: A new poly(ester amide)s (PEA) derived from L-lactic acid and α-alanine have been synthesized by melting copolymerization with p-toluenesulfonic acid (TSA) with stannous chloride (SnCl₂) as catalyst. The products were analyzed by NMR, FT IR techniques. The effects of the content of α-alanine (L-Ala) on the copolymers structure were studied. Being the phosphate buffered saline (pH=7.2) as the degradation solution, the degradation rate speed up with the increasing the content of the α-alanine.

Abstract: The spherical lignin/polylactide (PLA) adsorbent was prepared by solvent evaporation. The dispersed phase contents, the PLA concentration and ratio of PLA to lignin on the diameter and mechanical strength of the PLA/lignin composite adsorbent spheres were investigated and the morphology structure and mechanical strength of the adsorbent were characterized by scanning electron microscope (SEM) and dynamic mechanical analyzer (DMA). The results showed that the adsorbent has porous structure, and the mechanical strength increased significantly as the ratio of PLA to lignin as 4:1.

Abstract: Based on the novel USW method, the welds of Polylactide (PLA) - Polyformaldehyde (POM) and PLA - polymethyl methacrylate (PMMA) have been carried out. The interdiffusion processes of polymer chains have also been investigated according to the reptation theory and the hauling theory. The welding strengths are carried out by the universal tester and the rupture interfaces are observed using the scanning electron microscope. The best welding strength is 52MPa (90% compared with PLA of the PLA-POM system), which can reach the tensile strength of IPS. The molecules of POM are much easier to inter-diffuse than those of PLA and PMMA.

Abstract: Nanoclay/polylactide(PLA) nanocomposite was produced by the electrospinning process. The influences of nanoclays on the morphology and mechanical properties of the nanocomposite were investigated. The morphology and mechanical property of the nanocomposite were evaluated by scanning electron microscopy (SEM) and microtensile testing. SEM images revealed that submicron scale nanoclay/PLA nanocomposite fibers were fabricated and the introduction of nanoclay reduced the diameter of the nanofibers and improved the uniformity of the fibers. The addition of 1% nanoclay in PLA nanofibers leaded to simultaneous increases in the tensile strength, elongation at break and modulus for the PLA nanocomposite mat.

Abstract: In this research, short jute fiber reinforced polylactide composite, unidirectional long fiber reinforced polylactide composite and a sandwich structure polylactide composite were fabricated and the mechanical properties were tested. The mechanical properties of the fabricated composites were compared with those of a prototype spare tyre compartment cover of a passenger car. Tensile strength and flexural strength of all the composites are higher than those of the spare tyre compartment cover. The results show that the polylactide composites are applicable to car interior plates.

Abstract: This study designed a flexible electromagnetic resistant fabric it is not only apt to make protective clothing, but also simple process dependence on its application. Polylactide fiber (PLA) and the low melting polylactide fiber (LMPLA) were blended to fabricate nonwoven matrix. Then polyester (PET) aluminum foil inserted between two layers of PLA nonwoven matrix to fabricate a compound matrix by needle punching. Afterward, physical properties and electromagnetic shielding effectiveness of different layers compound matrix were be evaluated.The result indicated that Tensile strength of sample B was 189.16 N; tear strength of sample C was 579.43 N. Burst strength of sample B which was laminated five-layers compound matrix had best burst strength, 3326.18 N, and excellent electromagnetic shielding effectiveness, over 90 dB.