Article
Polymer Science
Yangzhe Hou, Han Jia, Yamin Pan, Chuntai Liu, Changyu Shen, Xianhu Liu
Summary: This study successfully prepared brand-new porous PLA films with enhanced flexibility and heat resistance using blade coating and thermally induced phase separation methods. The resulting blend films showed improved mechanical properties and high porosity, making them suitable for microfiltration, packaging, and modified applications.
Article
Polymer Science
Hideto Tsuji, Kazumasa Iguchi, Yuki Arakawa
Summary: The research studied the effects of different molecular weights of crystalline blocks but similar overall molecular weights on the crystallization behavior, structure, morphology, and thermal properties of PLLA-b-PDLLA/PDLA-b-PDLLA blends. It was found that the incorporated long amorphous PDLLA blocks facilitated unique SC crystallization in the blends with different crystalline block fractions.
Article
Polymer Science
Lidong Feng, Xinchao Bian, Gao Li, Xuesi Chen
Summary: By investigating the thermal properties, morphology, and thermal stability of PLLA/PDLA blends, a new stereoamorphous mesophase (sam-PLA) structure was discovered, and the relationship between different phases in the PLLA/PDLA blends was explored.
Article
Chemistry, Multidisciplinary
Chung-Fu Yu, Syang-Peng Rwei, Yao-Chi Shu
Summary: We synthesized a PLA-PETA polymer modified with acrylic trifunctional groups using a one-pot method based on ring-opening polymerization. Molecular weight and structure of PLA-PETA were determined using GPC and NMR spectroscopy. The photocrosslinked PLA-PETA showed high transparency and thermal stability, and exhibited good biocompatibility with cells.
Article
Chemistry, Applied
Yaowalak Srisuwan, Yodthong Baimark
Summary: This paper reports a study on flexible polymer blends made from PLLA-PEG-PLLA and TPS. The addition of TPS suppressed crystallizability of PLLA and PLLA-PEG-PLLA matrices, while greatly increasing the thermal stability of PLLA-PEG-PLLA. The PEG middle-blocks enhanced phase compatibility between PLLA-PEG-PLLA and TPS, resulting in ductile and flexible blend films.
CARBOHYDRATE POLYMERS
(2022)
Article
Polymer Science
Lidong Feng, Xinchao Bian, Gao Li, Xuesi Chen
Summary: The study shows that the compatibility between PLLA and PLDLA-m decreases as the L-lactate unit content in PLDLA-m decreases, impacting the crystallization and compatibility of the blends.
Article
Polymer Science
Suyang Dai, Ziming Dai, Ni Jiang, Zhenbo Ning, Zhihua Gan
Summary: In this study, poly(L-lactide) (PLLA) was toughened by crosslinked polyurethane (CPU) through reactive blending. The resulting material exhibited significant increase in elongation at break, enhanced toughness, and shape memory capacity, showing great potential for applications in biodegradable green composites.
Article
Polymer Science
Zhuoxin Zhuang, Tiantian Li, Zhenbo Ning, Ni Jiang, Zhihua Gan
Summary: The synthesis of lignin-grafted-poly (o-lactide) (LGPD) with different poly(o-lactide) (PDLA) block lengths improved the crystallization, mechanical properties, and UV-absorbance properties of poly(L-lactide) (PLLA). The longer PDLA block length in LGPD led to faster crystallization rates and broader melting ranges of stereocomplex (SC) crystallites. Moreover, the LGPD blends showed improved tensile strength and UV-absorbance properties compared to neat PLLA.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Polymer Science
Wenze Li, Mengyao Wang, Huan Luo, Yanhua Niu, Yajiang Huang, Guangxian Li
Summary: This study investigates the crystallization behaviors of stereocomplex and homochiral crystals by blending high molecular weight PLLA with low molecular weight PDLA and its diblock copolymers. It was found that the introduction of different sequences can inhibit the crystallization kinetics of the blends, with the formation of sc crystalites prior to hc ones. Additionally, micro phase separation between PLA and PDMS segments was observed to weaken the competition between sc and hc crystals.
Article
Chemistry, Multidisciplinary
Megha D. Deokar, Baijayantimala Garnaik, Swaminathan Sivaram
Summary: Well-defined six-arm star-branched bio-degradable block copolymers were prepared using controlled ring-opening polymerization and a sequential monomer addition method. The study found that the sequence of enchainment could be changed by reversing the order of monomer addition, resulting in different crystalline or amorphous blocks. However, disruption of the block structure was observed in one of the copolymers due to competing transesterification reactions. Differential scanning calorimetry studies showed interesting phase morphologies in these sequence-controlled block copolymers. Blending these copolymers with a commercially sourced polymer led to improved tensile toughness in the blend.
Article
Polymer Science
Prasong Srihanam, Yaowalak Srisuwan, Theeraphol Phromsopha, Apirada Manphae, Yodthong Baimark
Summary: In this study, the phase compatibility and mechanical properties of flexible poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLLA-PEG-PLLA)/thermoplastic starch (TPS) blends were improved by adding citric acid (CA) as a compatibilizer. The crystallinity of PLLA-PEG-PLLA matrix was suppressed and the thermal stability was enhanced by CA modification of TPS. The compatibility between TPS and PLLA-PEG-PLLA phases was improved, and the blends exhibited increased tensile strength, elongation at break, and Young's modulus with higher CA content.
Article
Engineering, Biomedical
Susan Bayati, Parmida Harirchi, Payam Zahedi, Abdolmajid Bayandori Moghaddam
Summary: This study aimed to develop a new bioactive wound dressing based on electrospun nanofibers containing Lawsonia inermis for burn wounds. The results showed that the dressing had a positive influence on wound closure and exhibited antibacterial properties.
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
(2023)
Article
Polymer Science
Yaowalak Srisuwan, Yodthong Baimark
Summary: In this study, high-molecular-weight poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) triblock copolymer (PLLA-PEG-PLLA) was used as a biodegradable bioplastic. However, its high cost and poor thermal stability limited its applications. Native cassava starch was blended to reduce the production cost and improve the thermal stability. The interaction between starch and PEG increased the thermal stability and phase adhesion, resulting in flexible and hydrophilic films with potential applications in biomedical, packaging, and agricultural fields.
Article
Biotechnology & Applied Microbiology
Tiantang Fan, Jingwen Qin, Xiao Meng, Jiafeng Li, Qing Liu, Guannan Wang
Summary: PLPG membranes with sc-PLA improved the crystallizing behavior of PLLA segments, increased thermal stability and degradation ability, and showed low cytotoxicity.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2022)
Article
Polymer Science
Prasong Srihanam, Wiriya Thongsomboon, Yodthong Baimark
Summary: The aim of this study was to modify PLLA-b-PEG-b-PLLA copolymer using low-cost CaCO3 filler to improve its material properties. The addition of CaCO3 enhanced the crystallinity and thermal stability of PLLA-b-PEG-b-PLLA matrix. SEM analysis showed stronger interfacial adhesion between PLLA-b-PEG-b-PLLA and CaCO3 compared to PLLA and CaCO3. Tensile testing revealed increased stress and modulus for PLLA-b-PEG-b-PLLA matrix with CaCO3, while these properties significantly decreased for PLLA matrix. Therefore, CaCO3 shows promise as an inexpensive filler for improving PLLA-b-PEG-b-PLLA bioplastics.
Article
Chemistry, Applied
Mayara R. Alves, Mateus F. Paiva, Pablo T. A. Campos, Elon F. de Freitas, Maria Clara H. Clemente, Gesley Alex Martins, Alceu T. Silveira Jr, Luis C. Cides da Silva, Marcia C. A. Fantini, Silvia C. L. Dias, Jose A. Dias
Summary: This research compared the accessibility and strength of silanol groups on ordered mesoporous silica materials with different pore structures. Various analytical methods were used to evaluate the donor-acceptor properties, including thermogravimetry and NMR. Differences in reactivity were discussed, highlighting the impact of surface silanol groups on the adsorption and reaction properties of the materials.
JOURNAL OF POROUS MATERIALS
(2021)
Article
Chemistry, Applied
Mateus Freitas Paiva, Gabriel Ali Atta Diab, Estelle Silva Diorato Teixeira de Mendonca, Silvia Claudia Loureiro Dias, Jose Alves Dias
Summary: Magnetic nanoparticles based on magnetite (MNP) coated with silica (MNP@SiO2) have various research applications, especially as catalyst supports. In this study, magnetite was coated with tetraethylorthosilicate (TEOS) and used as a support for phosphotungstic acid (HPW). The synthesized catalysts showed good dispersion and integrity of HPW, maintaining the structural and magnetic characteristics of MNP@SiO2. The catalysts exhibited high activity, selectivity, and stability in the esterification reaction of oleic acid with ethanol.
Article
Chemistry, Inorganic & Nuclear
Pablo Teles Aragao Campos, Claudinei Fabiano Oliveira, Joao Pedro Vieira Lima, Daniele Renata de Queiroz Silva, Silvia Claudia Loureiro Dias, Jose Alves Dias
Summary: In this study, cerium-zirconium mixed oxides were synthesized using the sol-gel methodology with CTAB for controlling the specific surface area and pore volume. The materials synthesized with CTAB showed higher oxygen vacancy compared to those prepared by conventional sol-gel process. The catalytic test suggested that the oxygen vacancy parameter is more important than the specific surface area itself.
JOURNAL OF SOLID STATE CHEMISTRY
(2022)
Article
Chemistry, Physical
Mateus Freitas Paiva, Elon Ferreira de Freitas, Juliene Oliveira Campos de Franca, Deborah da Silva Valadares, Silvia Claudia Loureiro Dias, Jose Alves Dias
Summary: The study demonstrates the advantageous performance of zeolite Y catalysts modified with HPW and HSiW acids in the esterification reaction of oleic acid with n-butanol. Through a series of physicochemical analyses and tests, it was concluded that the resulting acid composites showed superior properties compared to the pristine solids.
MOLECULAR CATALYSIS
(2022)
Article
Chemistry, Physical
Rudy Crisafulli, Dryade Ferreira de Paula, Sabrina C. Zignani, Lorenzo Spadaro, Alessandra Palella, Simona Boninelli, Jose A. Dias, Jose J. Linares
Summary: Using liquid fuels in fuel cells has advantages in terms of easier and safer handling, transportation, and storage. This study investigates the influence of copper as an auxiliary metal on palladium in direct hydrazine fuel cells. The addition of copper reduces the adsorption energies of adsorbed species and contributes to the oxidation of hydrazine, resulting in improved electroactivity. However, copper also slightly promotes the non-faradaic decomposition of hydrazine, leading to a slight loss in faradaic efficiency.
Review
Chemistry, Multidisciplinary
Deborah da Silva Valadares, Juliene Oliveira Campos de Franca, Roberto Chaves Fernandes, Luiz Marcos Dezaneti, Silvia Claudia Loureiro Dias, Jose Alves Dias
Summary: The calorimetry and adsorption (Cal-Ad) method, which combines two techniques, has been an important tool in chemistry for 36 years. It provides information about the thermodynamic parameters of catalysts, including the number, strength, and size of active sites. This method is based on the donor-acceptor concept and the Electrostatic Covalent Model (ECW), and has been widely applied in catalysis and material chemistry. By characterizing more than 25 catalysts and using spectroscopic and thermal methods, this review demonstrates the various applications of Cal-Ad method for acid-dependent reactions.
CHEMISTRY-SWITZERLAND
(2023)
Article
Chemistry, Multidisciplinary
Joao Pedro Vieira Lima, Pablo Teles Aragao Campos, Mateus Freitas Paiva, Jose J. Linares, Silvia C. L. Dias, Jose A. Dias
Summary: The study found that the acidity strength of catalysts, the quantity and accessibility of acid sites are crucial for the conversion and yield results. A synergic effect of acidity and mesoporous area are key factors affecting the activity and selectivity of the solid acids.
CHEMISTRY-SWITZERLAND
(2021)