Article
Polymer Science
Yajun Deng, Changan Zhang, Tao Zhang, Bo Wu, Yanmei Zhang, Jianhua Wu
Summary: In this study, a fluorinated waterborne polyurethane (FWPU) was successfully synthesized and its thermal stability and mechanical properties were improved by adding a cross-linking agent. The FWPU exhibited good hydrophobicity and mechanical properties, making it a promising alternative to other materials.
Article
Polymer Science
Reihaneh Farajollah, Mir Mohammad Alavi Nikje, Ebrahim Saadat, Farid Abedin Dorkoosh
Summary: In this study, a novel three-dimensional waterborne polymer network containing a pentol star core was designed and synthesized. The polymer showed increased hydrophilicity, degradability, and biocompatibility compared to the core material. These results suggest that the prepared polymer has potential for biomedical applications in the future.
EUROPEAN POLYMER JOURNAL
(2021)
Article
Polymer Science
Hesham Abdeldaim, Bernd Reck, Konrad J. Roschmann, Jose M. Asua
Summary: This article studies the effect of particle characteristics and drying conditions on stress generation and crack formation, and characterizes the morphology of particles and films in detail. The range of conditions necessary for crack-free, mechanically strong, low temperature film-forming coatings is determined. It is shown that existing mathematical models for cracking cannot explain the experimental data, and the reasons for this failure are discussed. A data-derived criterion for cracking nucleation is proposed.
Article
Materials Science, Multidisciplinary
Benjamin Rodriguez Hernandez, Antje Lieske
Summary: In this study, PEG, PPG, and PEPG were used as macroinitiators in the ring-opening polymerization of l-lactide to synthesize PLLA-b-polyether-b-PLLA linear triblock and starblock copolymers. The results showed that PEG and PEPG blocks were miscible with PLLA blocks, leading to a plasticization effect. On the other hand, PPG-containing block copolymers exhibited phase separation, resulting in microstructures in the melt. Tensile tests indicated that phase-separated PPG-containing block copolymers were more ductile than PLA homopolymers but more brittle than PEG- or PEPG-plasticized block copolymers.
MACROMOLECULAR MATERIALS AND ENGINEERING
(2023)
Article
Chemistry, Applied
Min Su Kim, Kyoung Moon Ryu, Sang Hoon Lee, Young Chul Choi, Sangchul Rho, Young Gyu Jeong
Summary: This study focused on the fabrication of cationic waterborne polyurethane (cWPU) nanocomposite films reinforced with chitin nanofibers (ChNF) and investigated their microstructure, thermal, and mechanical properties. The results showed that the addition of ChNF can increase the thermal decomposition temperature and storage modulus of the composite films.
CARBOHYDRATE POLYMERS
(2021)
Article
Polymer Science
Kristyna Janegova, Petr Sysel, Hana Kulhankova, Viacheslav A. Perfilov, Milan Bernauer, Vlastimil Fila
Summary: This study focuses on the properties of polyimides containing siloxane moieties in various advanced applications, such as separation membranes. The research found significant differences in water contact angle and gas transport properties among films with different compositions, with the membrane composition having a greater impact on gas transport properties than surface properties.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Chemistry, Applied
Barry Reid, Ishaa Mane, Faizah Ahmed, Maximiliano Jara Fornerod, Mate Fueredi, Benjamin Schmidt-Hansberg, Alberto Alvarez-Fernandez, Stefan Guldin
Summary: This study provides a comprehensive investigation into the relationship between the porosity, material processing, and mechanical properties of mesoporous coatings. Various methods are explored to improve the scratch resistance and mechanical performance, with the introduction of organic chelating agents being particularly promising.
MICROPOROUS AND MESOPOROUS MATERIALS
(2022)
Article
Polymer Science
Elisheva Michman, Meirav Oded, Roy Shenhar
Summary: By simply casting ultra-thin block copolymer films on topographically defined substrates, hierarchical structures with dual patterns can be achieved in a controlled manner, offering enhanced defect tolerance and simplified fabrication processes. The extreme of ultraconfined thickness regime at the border of film dewetting reveals additional non-bulk morphologies, expanding the possibilities for obtaining dual patterns alongside full placement control. The width of the plateaus becomes a critical factor influencing the local morphology as the thickness confinement approaches its limit.
Article
Chemistry, Physical
Veronika Gajdosova, Milena Spirkova, Yareni Aguilar Costumbre, Sabina Krejcikova, Beata Strachota, Miroslav Slouf, Adam Strachota
Summary: The morphology, macro-, and micromechanical properties of novel poly(urethane-urea)/silica nanocomposites were investigated. These materials showed complex elastoviscoplastic behavior and were of great interest for microindentation studies. The properties correlated strongly, and the relationships were affected by hydrogen bonding, nanofiller distribution, and material deformation.
Article
Polymer Science
Milena Spirkova, Jelena Pavlicevic, Yareni Aguilar Costumbre, Jiri Hodan, Martina Urbanova, Sabina Krejcikova
Summary: A series of transparent waterborne poly(urethane-urea) (PUU) films and nanocomposite films were prepared by using excess isocyanate and omitting the common chain-extension step. The surplus isocyanate groups were converted into urea and biuret linkages during the last phase inversion step. The variable urea/biuret content resulted in substantially different tensile properties, with potential for use as topcoats depending on specific demands, with the most promising materials prepared at 30 and 40 mol% isocyanate excess.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Polymer Science
Vladislav Istratov, Vitaliy Gomzyak, Valerii Vasnev, Oleg V. V. Baranov, Yaroslav Mezhuev, Inessa Gritskova
Summary: The synthesis and application of lactic acid-based polyesters for the creation of implants have gained increased interest due to their biocompatibility, biodegradability, and high mechanical strength. However, the hydrophobicity of polylactide limits its use in biomedical fields. This study focused on the synthesis of amphiphilic branched pegylated copolylactides to introduce hydrophilic groups and improve the properties of polylactide. The resulting copolylactides were used to prepare interpolymer mixtures with PLLA, leading to reduced brittleness, increased hydrophilicity, and water absorption. Furthermore, filling the polylactide films with hydroxyapatite further decreased the water contact angle and increased thermal stability.
Article
Polymer Science
Takaya Ikami, Yuki Watanabe, Hiroki Ogawa, Mikihito Takenaka, Norifumi L. Yamada, Makoto Ouchi, Hiroyuki Aoki, Takaya Terashima
Summary: By controlling the composition of the copolymers with octadecyl groups and hydroxyethyl groups in solution, ordered lamellar structures can be formed in the solid state, while spin-coating the polymer solutions onto silicon substrates allows the copolymers to autonomously form multilayered lamellar thin films.
Article
Chemistry, Multidisciplinary
Wei Wei, Muhammad Amjad Farooq, Huiming Xiong
Summary: This new type of polyether-based cholesteric liquid crystalline copolymers can achieve strong circularly polarized luminescence with high purity and broad tunability. By altering composition or temperature, the reflection colors across the infrared and visible light regions can be continuously tuned. Introducing achiral dyes in the unique structure can generate strong circularly polarized luminescence with high dissymmetry factors and distinct handedness.
Article
Polymer Science
Li-Ping Zhang, Zhen-Guo Zhao, Yuan-Yuan Huang, Chang-Jian Zhu, Xing Cao, Yan-Peng Ni
Summary: Waterborne polyurethanes (WPUs) are environmentally friendly and widely used in production and daily life, but they are flammable. This study presents a novel flame-retardant additive, BIEP-ETA, which improves the flame resistance of WPUs by forming hydrogen bonds and phosphorus nitrogen synergistic effect. The WPU blends (WPU/FRs) showed improved fire-retardant effect, emulsion stability, mechanical properties, and corrosion resistance.
Review
Engineering, Chemical
Veronica L. Mucci, Maria E. V. Hormaiztegui, Javier I. Amalvy, Mirta I. Aranguren
Summary: Recently, there has been increased research and development activity on water-based formulations for films and coatings due to the need for environmentally friendly materials. Waterborne polyurethanes (WBPUs) have been developed to release harmless water instead of volatile organic compounds (VOCs) during coating deposition or the formation of self-standing films. This review focuses on the relationship between formulation-structure and properties of these materials, as well as the commonly used application methods and their relation to dispersion viscosity. Additionally, composite formulations have been tailored by incorporating organic and inorganic particles/nanoparticles to enhance performance for the final application.
JOURNAL OF ADHESION SCIENCE AND TECHNOLOGY
(2023)
