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 >

SAMANEH MOSTAFAVI, ZUHAIR MOHAMMAD HASSAN^*

Oncology Research, Vol.32, No.3, pp. 477-487, 2024, DOI:10.32604/or.2023.043926

Abstract Intracellular communications between breast cancer and fibroblast cells were reported to be involved in cancer proliferation, growth, and therapy resistance. The hallmarks of cancer-fibroblast interactions, consisting of caveolin 1 (Cav1) and mono-carboxylate transporter 4 (MCT4) (metabolic coupling markers), along with IL-6, TGFβ, and lactate secretion, are considered robust biomarkers predicting recurrence and metastasis. In order to promote a novel phenotype in normal fibroblasts, we predicted that breast cancer cells could be able to cause loss of Cav1 and increase of MCT4, as well as elevate IL-6 and TGFβ in nearby normal fibroblasts. We created a co-culture model using breast cancer… 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

Penghui Li^1,2, Zhengwei Jiang², Chi Yang², Jianpeng Ren^1,2, Bo Jiang^1,2, Wenjuan Wu^1,2,*

Journal of Renewable Materials, Vol.11, No.5, pp. 2233-2248, 2023, DOI:10.32604/jrm.2023.025279

Abstract Lignin is a natural polymer, second only to cellulose in natural reserves. Degradation is one of the ways to achieve the high-value transformation of lignin. Deep eutectic solvent (DES) thermal degradation of lignin can be used as an excellent green degradation method. This paper introduces the degradation mechanism and effect of the lactic acid-choline chloride DES system in dissolving and degrading alkaline lignin, and the final solvent recovery. It can also be found from the scanning electron microscope (SEM) images that the surface of the degraded solid product is transformed from smooth to disordered. Fourier transform infrared (FTIR) spectroscopy and… More > Graphic Abstract

Yodthong Baimark^*, Theeraphol Phromsopha

Journal of Renewable Materials, Vol.11, No.4, pp. 1881-1894, 2023, DOI:10.32604/jrm.2023.025400

Abstract A poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide)(PLLA-PEG-PLLA) block copolymer has great potential for use as a flexible bioplastic. Highly flexible bioplastics are required for flexible packaging applications. In this work, a PEG was incorporated into block copolymer as a plasticizer by solvent casting. PLLA-PEG-PLLA/ PEG blends with different blend ratios were prepared, and the plasticizing effect and miscibility of PEG in block copolymer were intensively investigated compared to PLLA/PEG blends. The results indicated that the PEG was an effective plasticizer for the block copolymer. The blending of PEG decreased glass-transition temperature and accelerated the crystallization of both the PLLA and PLLA-PEG-PLLA matrices. The PEG… More > Graphic Abstract

Chengtao Gao^1,2, Yang Wu³, Haibo Xie^1,*

Journal of Renewable Materials, Vol.11, No.3, pp. 1137-1152, 2023, DOI:10.32604/jrm.2022.021473

Abstract

Due to the increasing demand for modified polylactide (PLA) meeting “double green” criteria, the research on sustainable plasticizers for PLA has attracted broad attentions. This study reported an open-ring polymerization method to fabricate cellulose (MCC)-g-PCL (poly (ε-caprolactone)) copolymers with a fully sustainable and biodegradable component. MCC-g-PCL copolymers were synthesized, characterized, and used as green plasticizers for the PLA toughening. The results indicated that the MCC-g-PCL derivatives play an important role in the compatibility, crystallization, and toughening of the PLA/MCC-g-PCL composites. The mechanical properties of the fully bio-based PLA/MCC-g-PCL composites were optimized by adding 15 wt% MCC-g-PCL, that is, the elongation… 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 >

Xiaoqing Zhang^*, Simon Schmidt^φ, Nick Rigopoulos, Januar Gotama, Eustathios Petinakis

Journal of Renewable Materials, Vol.3, No.2, pp. 91-100, 2015, DOI:10.7569/JRM.2014.634135

Abstract The behavior of a biodegradable CO₂ -based polymer polypropylene carbonate (PPC) as polymer matrix of wood fi ber (WF) composites was examined and compared with that of using poly(lactic acid) (PLA) as the matrix. The PPC/WF composites displayed poor mechanical properties as compared to PLA/WF composites because PPC is an amorphous polymer with low T_g and poor thermal stability. However, when PPC was used in conjunction with PLA in WF composites, the mechanical strength and modulus of the composites could match or even exceed the level of PLA/WF composites. The strong intermolecular interactions between PPC and WF and those between… 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