Article
Agricultural Engineering
Thayli Ramires Araujo, Daniela Bresolin, Debora de Oliveira, Claudia Sayer, Pedro Henrique Hermes de Araujo, Jose Vladimir Oliveira
Summary: In this study, biopolyols were synthesized by enzyme-catalyzed transesterification using lignin as the substrate, and high-density rigid foams were obtained through polymerization.
INDUSTRIAL CROPS AND PRODUCTS
(2023)
Article
Engineering, Environmental
Yufeng Zheng, Yuying Zhao, Run Su, Ni An, Youliang Zhang, Yan Wei, Bin Ma
Summary: A novel method using polyurethane foam carriers for rapidly immobilizing slow-growing anammox bacteria through dewatering was proposed in this study. The carriers retained 83.12 +/- 3.24 % of the sucked sludge under shear conditions after natural dewatering for 12 h. The specific anammox activity of the bacteria retained in the carriers was lost by 19.95 +/- 1.37 % during the dewatering process. This dewatering immobilization method relies on the cross-linking of alginate-like exopolysaccharides with Ca2+ and the network structure of polyurethane foam carrier. It provides an easy and low-cost approach for rapid immobilization of slow-growing anammox bacteria.
JOURNAL OF WATER PROCESS ENGINEERING
(2023)
Article
Engineering, Environmental
Daniela Bresolin, Ariovaldo Bolzan, Claudia Sayer, Pedro Henrique Hermes de Araujo, Debora de Oliveira
Summary: In this study, biopolyols derived from castor oil and glycerol were synthesized using Novozym 435 and Eversa Transform 2.0 lipases. The biopolyols showed different characteristics when used for the synthesis of polyurethane foams, with N435-derived biopolyol providing better mechanical properties. However, the use of Eversa Transform 2.0 lipase suggests the potential for low-cost enzyme production of biopolyols and foams, possibly competing with chemical catalysts.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2021)
Article
Biochemistry & Molecular Biology
Naba Kumar Kalita, Minna Hakkarainen
Summary: A green strategy was demonstrated to accelerate the biodegradation rate of cellulose acetate (CA) through deacetylation. The immobilization of lipase from Candida rugosa on CA particles resulted in significant deacetylation, as evidenced by changes in molecular weight and water contact angle. This approach showed promising potential for developing modified lignocellulose materials with retained biodegradability.
Article
Materials Science, Multidisciplinary
Hyewon Song, Cheol Hyun Park, Sun Hwan Jeong, Jun Hyuk Heo, Jung Heon Lee
Summary: Considering the persistent problem of fire safety in polymeric materials, including polyurethane foam, there is a growing demand for flame retardants (FRs). This study demonstrates the successful coating of PU foam with a layer-by-layer assembly of adenosine triphosphate (ATP) and chitosan (CS) as an effective FR. The coated PU foam exhibited excellent fire retardancy, with a high limiting oxygen index value, reduced heat release rate, and decreased smoke release.
ACS APPLIED POLYMER MATERIALS
(2023)
Article
Construction & Building Technology
Yubin Zhou, Yachao Wang, Kang Yu, Shaoqing Feng, Hongji Zhang, Jiangping Zhao
Summary: This study successfully incorporates a ternary flame-retardant system of piperazine pyrophosphate/magnesium hydroxide/fly ash cenospheres into rigid polyurethane foams, enhancing the flame retardancy and mechanical properties of the materials, and demonstrating excellent adsorption performance and thermal stability.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Biochemistry & Molecular Biology
Marcin Borowicz, Marek Isbrandt, Joanna Paciorek-Sadowska
Summary: The research aimed to obtain two new eco-polyols based on waste polylactide (PLA) and tested their effects on rigid polyurethane and polyisocyanurate foams. Analysis showed that partial replacement of petrochemical polyol by eco-polyols resulted in better performance in terms of density, compressive strength, brittleness, water absorption, and aging resistance for both RPU/PIR and PRU foams.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Editorial Material
Chemistry, Multidisciplinary
Alexandra D. Easley, Alison Mangano, Brett P. Fors
Summary: Polyurethanes (PUs) are synthesized materials commonly made from isocyanates, diols, and water. Water plays a crucial role in the production of carbon dioxide (CO2) used for self-blowing of the foams. To address safety concerns, researchers have explored alternative chemistries, and cyclic carbonate systems have shown great promise. In a recent study, Bourguignon, Grignard, and Detrembleur demonstrated that a cyclic carbonate and diamine system can generate CO2 for self-blowing through hydrolysis, allowing for a wide range of physical and thermo-mechanical properties. This work represents a significant advancement towards safer and more environmentally friendly PUs.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Shenghe Zhang, Fukai Chu, Zhoumei Xu, Yifan Zhou, Yong Qiu, Lijun Qian, Yuan Hu, Bibo Wang, Weizhao Hu
Summary: In this study, the effects of three different phosphorus-containing compounds on the flame-retardant performance of FPUF were investigated, and their flame-retardant mechanism was explored. Among them, MPBT showed the highest flame-retardant efficiency. Increasing the addition amount of MPBT resulted in improved comprehensive performance of flame-retardant FPUF.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Chemistry, Applied
Sara Arana-Pena, Nathalia S. Rios, Diego Carballares, Luciana R. B. Goncalves, Roberto Fernandez-Lafuente
Summary: CALB and CRL showed similar properties under different immobilization conditions, while RML displayed significant changes. The effects of immobilization conditions on substrate activity and stability vary greatly, requiring careful selection based on specific circumstances.
Article
Engineering, Chemical
Jiazi Wu, Xin Zhang, Zhaolu Qin, Wenchao Zhang, Rongjie Yang
Summary: Flame-retardant rigid polyurethane foam (RPUF) composites were fabricated using different flame retardants (APP, PEPA, PCP, and ADP), labeled as RPUF-1, RPUF-2, and RPUF-3. The effects of flame retardants on the apparent density and compressive strength of RPUF were studied. Results showed that flame retardants improved both the apparent density and compressive strength of RPUF composites. The inorganic/organic phosphorus-based flame retardants significantly improved the limiting oxygen index (LOI), especially in RPUF-2 and RPUF-3 systems. Cone calorimeter tests revealed a decrease in heat release for RPUF-1, RPUF-2, and RPUF-3 systems compared to pure RPUF, with APP and ADP system performing the best in reducing heat release, and APP and PEPA systems performing the best in decreasing smoke release. The flame retardancy mechanism of RPUF composites was analyzed in detail.
POLYMER ENGINEERING AND SCIENCE
(2023)
Article
Nanoscience & Nanotechnology
Hao Dong, Wenxue Zhang, Qize Xuan, Yao Zhou, Shengmin Zhou, Jiaofang Huang, Ping Wang
Summary: By phage display screening and co-expression of CsgB and LBP2-modified CsgA proteins, E. coli biofilms were developed as a surface for enzyme immobilization, resulting in enhanced catalytic performance of lipase when immobilized on LBP2-functionalized biofilm materials.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Qianqian Hu, Guoning Chen, Lu Wang, Xia Cui, Chun Chang, Qiang Fu
Summary: This study immobilized sarcosine oxidase to improve its stability and developed a fluorescence method for rapid and accurate detection of sarcosine. The method showed high sensitivity, specificity, and ease of use, making it suitable for laboratory and community-level medical institutions.
NEW JOURNAL OF CHEMISTRY
(2022)
Review
Biochemistry & Molecular Biology
F. Rafiee, M. Rezaee
Summary: Immobilized enzymes, particularly lipase on chitosan support, have attracted significant attention due to their advantages in industry and biochemistry. This review highlights the recent studies on lipase immobilization and discusses the potential solutions for current limitations.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2021)
Article
Polymer Science
Harry Charles Wright, Duncan Drummond Cameron, Anthony John Ryan
Summary: Polyurethane foams are versatile but challenging to formulate. This study demonstrates an experimental design framework combined with a design of experiments approach to reduce the number of experiments required and decrease the reliance on expert knowledge. By exploring the relationship between catalyst and surfactant loadings, the foam physical properties can be modeled and the cell morphology and hydrodynamic behavior of the foam can be investigated.