A. MADHAN KUMAR¹, K. JAYAKUMAR^2,*, M. SHALINI³

Journal of Polymer Materials, Vol.39, No.3-4, pp. 269-281, 2022, DOI:10.32381/JPM.2022.39.3-4.7

Abstract Polylactic acid (PLA) is the most popular thermoplastic biopolymer providing a stiffness and strength alternative to fossil-based plastics. It is also the most promising biodegradable polymer on the market right now, thus gaining a substitute for conservative artificial polymers. Therefore, the current research focuses on synthesizing and mechanical characterization of particlereinforced PLA composites. The hot compression molding technique was used to fabricate PLA-based composites with 0, 2.5, 5, and 7.5 weight % of sawdust, rice husk, and bagasse particle reinforcements to enhance the performance of the PLA. The pellets of PLA matrix were taken with an average size of 3… More >

Shuang Zhao¹, Shenglan Chen², Shuan Ren¹, Gang Li³, Ke Song^1,4, Jie Guo^1,4, Shima Liu^1,4, Jian He^1,4, Xianwu Zhou^1,4,*

Journal of Renewable Materials, Vol.11, No.6, pp. 2531-2553, 2023, DOI:10.32604/jrm.2023.026066

Abstract Petroleum-based materials, such as plastic, are characterized by adverse environmental pollution; as a result, researchers have sought alternative degradable plastics that are environmentally friendly, such as polylactic acid (PLA). PLA has shown great potential to replace petroleum-based plastics. In this study, seven different samples of unmodified Pueraria lobata root powder (PRP) with different contents (i.e., 0, 5, 10, 15, 20, 25, and 30 wt%) and three different modified PRPs (i.e., treated with NaOH, NaOH-KH-550, and Formic) were used to reinforce polylactic acid (PLA) via solution casting process. These prepared PRP/PLA composite films were characterized using SEM, FTIR, UV-visible spectra analysis,… More > Graphic Abstract

David Grewell^1,*, Gowrishankar Srinivasan¹, Eric Cochran²

Journal of Renewable Materials, Vol.2, No.3, pp. 157-165, 2014, DOI:10.7569/JRM.2014.634112

Abstract Presented in this study is a novel recycling strategy for poly(lactic acid) (PLA) in which the depolymerization is rapidly promoted by the base-catalyzed hydrol-/alcohol-ysis of the terminal ester bonds under mild conditions. Post-consumer PLA water bottles were cut into approximately 6 x 2 mm plastic chips and heated to 50–60o C in water, ethanol, or methanol as the depolymerization medium. A variety of carbonate salts and alkaline metal oxides were screened as potential catalysts. High-power ultrasound was also investigated as a means to accelerate the PLA decomposition. Both mass loss and HPLC analysis of the treated suspensions showed that the… More >

Hedieh Teymoorzadeh¹, Denis Rodrigue^2,*

Journal of Renewable Materials, Vol.2, No.4, pp. 270-277, 2014, DOI:10.7569/JRM.2014.634127

Abstract This work investigates the effect of the addition of fl ax fi ber (15, 25, and 40 wt%) on the mechanical, morphological, rheological, and thermal properties of polylactic acid (PLA). In the fi rst step, no coupling agent was used to produce fully biodegradable and biobased composites. In particular, fl exural tests were performed on the composites to evaluate their mechanical properties, while density, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and rheological tests were also carried out. Scanning electron microscopy images (SEM) show good fl ax fi ber dispersion in the PLA matrix along with good contact between both… More >

Chaodong Liu, Yutong Yang, Boyu Cui, Weihong Wang^*

Journal of Renewable Materials, Vol.10, No.11, pp. 2961-2972, 2022, DOI:10.32604/jrm.2022.019761

Abstract Microfibrillated cellulose (MFC) is often added to polylactic acid (PLA) matrixes as a reinforcing filler to obtain fully-biodegradable composites with improved mechanical properties. However, the incompatibility between MFC and the PLA matrix limits the mechanical performance of MFC-reinforced PLA composites. In this paper, DL-lactic acid-grafted-MFC (MFC-g-DL) was used to improve the compatibility with PLA. Reinforced composites were prepared by melt extrusion and hot-cold pressing. The tensile strength of the PLA/MFC-g-DL composite increased by 22.1% compared with that of PLA after adding 1% MFC-g-DL. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and dynamic thermomechanical analysis (DMA) were used to explore… More > Graphic Abstract

Ping Zhang, Siyu Gan, Lin Chen^*, Hao Chen, Chunhui Jia, Yingke Fu, Ying Xiong^*

Journal of Renewable Materials, Vol.10, No.11, pp. 2937-2947, 2022, DOI:10.32604/jrm.2022.019590

Abstract Nano filler synergistic intumescent flame retardant (IFR) system is an effective way to improve the flame retardant properties of polymer. In this study, the effects of montmorillonite (MMT) on the flame retardant properties of polylactic acid/layered double hydroxides (PLA/LDH) and PLA/IFR/LDH were investigated. The results show that both LDH and LDH/IFR can reduce the peak heat release rate (HRR) of PLA and prolong the combustion time of PLA; When a proportionate MMT is introduced into PLA/LDH and PLA/IFR/LDH systems, respectively, MMT will not only affect the degradation process of PLA composites during combustion, but also the PLA composites can form… More >

Mahmood Hameed Majeed^*, Nabeel Kadhem Abd Alsaheb

Journal of Renewable Materials, Vol.10, No.9, pp. 2391-2408, 2022, DOI:10.32604/jrm.2022.019887

Abstract Tissue engineering’s main goal is to regenerate or replace tissues or organs that have been destroyed by disease, injury, or congenital disabilities. Tissue engineering now uses artificial supporting structures called scaffolds to restore damaged tissues and organs. These are utilized to attach the right cells and then grow them. Rapid prototyping appears to be the most promising technology due to its high level of precision and control. Bone tissue replacement “scaffolding” is a common theme discussed in this article. The fused deposition technique was used to construct our scaffold, and a polymer called polylactic acids and soybean oil resin were… More > Graphic Abstract

MARÍA G. FLORES-SÁNCHEZ^1,*, ROBERTO OLAYO², J. MORALES-CORONA², ATLÁNTIDA M. RAYA-RIVERA³, DIEGO R. ESQUILIANO-RENDÓN³

BIOCELL, Vol.46, No.3, pp. 829-836, 2022, DOI:10.32604/biocell.2022.016988

Abstract This article presents the construction of scaffolds composed of polylactic acid (PLA) with different concentrations of hydroxyapatite (HA) by electrospinning, which were superficially modified with polypyrrole (PPy/I) by plasma polymerization. A preliminary study was conducted of the biological and mechanical behavior of the scaffolds when they were implanted in the back of rabbits for 30 days; bone cells differentiated from mesenchymal stem cells (MSCs) were used. The bone cell and scaffold structures were characterized by histological, immunohistochemical, and mechanical stress tests. Hematoxylin–eosin staining showed good tissue conformation. The immunohistochemical tests highlighted the presence of the main bone tissue proteins, such… More >

Vignesh Sekar^1,*, Se Yong Eh Noum¹, Azma Putra², Sivakumar Sivanesan¹, Kok Chun Chin¹, Yi San Wong¹, Dg Hafizah Kassim³

Sound & Vibration, Vol.55, No.4, pp. 343-352, 2021, DOI:10.32604/sv.2021.014916

Abstract This paper presents the development and performance of micro-perforated panels (MPP) from natural fiber reinforced composites. The MPP is made of Polylactic Acid (PLA) reinforced with Oil Palm Empty Fruit Bunch Fiber (OPEFBF). The investigation was made by varying the fiber density, air gap, and perforation ratio to observe the effect on the Sound Absorption Coefficient (SAC) through the experiment in an impedance tube. It is found that the peak level of SAC is not affected, but the peak frequency shifts to lower frequency when the fiber density is increased. This phenomenon might be due to the presence of porosity… More >

Liqiong Ding¹, Pingsheng Li², Liu He¹, Fengnan Xu¹, Jieqiong Ding^3,*, Binhua Luo^1,*

Journal of Renewable Materials, Vol.10, No.3, pp. 767-780, 2022, DOI:10.32604/jrm.2022.016903

Abstract The development of contrast agents that can be activated by multiple modes is of great significance for tumor diagnosis. In this study, the lactoferrin (Lf)-conjugated polylactic acid (PLLA) nanobubbles (Lf-PLLA NBs) were used to encapsulate liquid perfluoropentane (PFP) with the double emulsion method, creating PFP loaded (PFP/Lf-PLLA) NBs for the ultrasound/magnetic resonance dual-modality imaging of subcutaneous tumor. The particle diameter and stability of nanobubbles were investigated by photon correlation spectroscopy. The biocompatibility of nanobubbles was preliminarily evaluated by cell proliferation and migration assay, hemolysis rate, and blood biochemistry analysis. A B-mode clinical ultrasound real-time imaging system was used to perform… More >