Article
Chemistry, Multidisciplinary
Jinchuan Zhao, Guilong Wang, Aimin Zhang, Guoqun Zhao, Chul B. Park
Summary: Microcellular foaming is an advanced and eco-friendly technology that utilizes carbon dioxide as a blowing agent. Stretch-assisted microcellular foaming has been developed to prepare TPU and its composite foams with refined cellular structures, where stretch is shown to promote cell nucleation significantly. The refined cellular morphology is achieved by the synergistic effect of stretch-induced and phase-induced cell nucleation in the foaming process.
JOURNAL OF CO2 UTILIZATION
(2021)
Article
Materials Science, Characterization & Testing
Nora Lukacs, Ferenc Ronkay, Bela Molnar, Botond Marosfoi, Katalin Bocz
Summary: CO2-assisted batch foaming was used to manufacture low-density microcellular foams from recycled PET with flame retardant properties. The foamability was enhanced by reactive chain extender and the flame retardant properties were improved by incorporating aluminium-tris-(diethylphosphinate) flame retardant. Adding natural montmorillonite and polytetrafluoroethylene powder improved the uniformity of cellular size and distribution. The presence of flame retardants inhibited the flame and promoted charring of the foams, resulting in reduced heat release rate and increased charring. The mechanical performance of the foams was primarily determined by the density and strain-induced crystallization increased their thermomechanical resistance.
Article
Nanoscience & Nanotechnology
Jianpeng Feng, Kangjie Zhou, Changsha Liu, Qi Hu, Hui Fang, Hengpan Yang, Chuanxin He
Summary: In this study, a free-standing electrocatalyst was constructed by confining a superbase and hydrophobic ionic liquid into Ni foam pores. This strategy successfully suppresses the hydrogen evolution reaction and improves the efficiency of CO2 reduction. The high CO2 capacity and modulation effect of the ionic liquid also play a positive role in the reaction.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Suset Barroso-Solares, Victoria Bernardo, Daniel Cuadra-Rodriguez, Javier Pinto
Summary: Blends of PMMA and MAM were obtained through two production routes and their nanostructures and self-assembly capabilities were analyzed using TEM and HRSEM. It was found that the nanostructure influenced the cellular structure of film and bulk samples, and a detailed scheme for cell nucleation, growth, and stabilization was proposed.
Article
Polymer Science
Yaozhuo Su, Pengke Huang, Jie Sun, Jiali Chen, Hao Zheng, Haibin Luo, Yunkai Chong, Yongqing Zhao, Fei Wu, Wenge Zheng
Summary: In this study, modified PLA beads are foamed using one-step, anhydrous supercritical CO2 extrusion, which significantly reduces production time and prevents pyrohydrolysis of PLA while avoiding wastewater generation. The use of a chain extender increases the melt strength of PLA. The PLA bead foam obtained by extrusion foaming with wind-cooling pelletizing technology exhibits a high expansion ratio, typical cellular morphology, and glossy surface. This research is beneficial for the continuous preparation of PLA bead foam and other polymer beads such as PS and PP, with applications in green packaging, sound absorption, cold-chain logistics, and more.
JOURNAL OF APPLIED POLYMER SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
Yaozhuo Su, Pengke Huang, Haibin Luo, Yunkai Chong, Yongqing Zhao, Minghui Wu, Hao Zheng, Xiaoqin Lan, Fei Wu, Wenge Zheng
Summary: This study creatively used supercritical CO2 extrusion foaming combined with wind-cooling granulator technology to prepare controllable polypropylene (PP)/thermoplastic polyurethane (TPU) composite bead foams. The process of polymer melting, gas dispersion, foaming, and pelletizing can be completed in one continuous step, with advantages such as high efficiency, low cost, and controllable cellular structures. The effect of processing parameters on the cellular structures and properties of the foam board was also studied. The prepared foam board exhibited low density and thermal conductivity, making it suitable for thermal insulation applications.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Polymer Science
Simon Faba, Marina P. Arrieta, Angel Aguero, Alejandra Torres, Julio Romero, Adrian Rojas, Maria Jose Galotto
Summary: This article proposes a method using supercritical carbon dioxide (scCO(2)) to obtain compostable bionanocomposite foams based on PLA and organoclay. The foams showed a closed cell and uniform cell structure with enhanced thermal stability and improved overall mechanical performance. The water uptake behavior demonstrated that the foams had low water absorption, and they also disintegrated under composting conditions. Therefore, these bionanocomposite foams seem to be a promising sustainable alternative for applications such as food packaging.
Article
Polymer Science
Joseph A. Sarver, Jenna L. Sumey, Richard M. Whitfield, Erdogan Kiran
Summary: Confined foaming leads to smaller and more uniformly distributed pores, but the bulk foam densities are higher compared to free-foaming. Surface characteristics and skin layer formation of the foams are altered under confinement conditions.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Polymer Science
Imene Ben Djemaa, Sebastien Andrieux, Stephane Auguste, Leandro Jacomine, Malgorzata Tarnowska, Wiebke Drenckhan-Andreatta
Summary: The reliable generation of hydrogel foams is still a challenge in various sectors. This study introduces a novel method using CO2 to foam and reduce the pH of alginate solution for gelation. Different gas fractions of gelled foams can be generated in a one-step process. The role of CO2 in foam ageing is investigated using foam stability measurements and interfacial rheology.
Article
Chemistry, Physical
Takumi Ono, Takeshi Furuya, Hiroyuki Niino, Satoshi Yoda
Summary: The use of HCFC-22/CO2 binary mixtures as blowing agents can improve the homogeneity and porosity of PMMA foams, leading to a more uniform cellular structure with smaller cell sizes.
JOURNAL OF SUPERCRITICAL FLUIDS
(2022)
Article
Engineering, Multidisciplinary
Zhanlin Shi, Guoqun Zhao, Lei Zhang, Guilong Wang
Summary: The innovative method of blending PVDF with PMMA resulted in foam with wider foaming window and excellent performance. The blend foams showed improved expansion ratio, thermal insulation, and flame retardancy, with high rigidity and lower heat release rate.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Binbin Sun, Jun Li, Yahao Guo, Heng Li, Hao-Yang Mi, Binbin Dong, Chuntai Liu, Changyu Shen
Summary: An extremely superhydrophobic and exceptionally robust foam based on ultrahigh-molecular weight poly-ethylene (UHMWPE) was developed using supercritical carbon dioxide (scCO2) foaming and subsequent surface modification. The foam demonstrated unprecedented water contact angle of 162 degrees and high separation efficiency in oil absorption and oil/water separation. With outstanding tolerance against mechanical damages, the foam has great potential for practical applications in water remediation and oil recycling.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Pengke Huang, Yaozhuo Su, Fei Wu, Patrick C. Lee, Haibin Luo, Xiaoqin Lan, Liyang Zhang, Bin Shen, Long Wang, Wenge Zheng
Summary: Original polypropylene foams with radially gradient porous structures and selective filtration were developed through supercritical CO2 assisted extrusion foaming and stretching auxiliary. The foam exhibits unique physical characteristics and potential applications in selective filtration properties.
JOURNAL OF CO2 UTILIZATION
(2022)
Article
Engineering, Manufacturing
Yaguang Yang, Xia Liao, Cuifang Lv, Bo Wang, Fangfang Zou, Guangxian Li
Summary: A combination of mechanical mixing and supercritical carbon dioxide foaming was used to prepare ultralightweight polymer microcellular foam. The addition of water and ultrasound enhanced the polymer foaming behavior, resulting in a significantly increased foam expansion ratio. The prepared foams exhibited an expansion ratio of 79 and a low thermal conductivity of 26.79 mW/mK. Ultrasound affected both the saturation and release stages of foaming, with a more pronounced effect observed in the release stage. This study presents a novel, facile, versatile, and green approach for preparing microcellular polymers with ultralightweight and superior thermal insulation.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2023)
Article
Chemistry, Physical
Xiaoyue Ren, Heng Li, Hao-Yang Mi, Yahao Guo, Xin Jing, Binbin Dong, Chuntai Liu, Changyu Shen
Summary: In this study, superhydrophobic nanocomposite foams were developed using melt blending and supercritical CO2 foaming techniques. The foam exhibited stable high performance in removing oil from water.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Kota Seshimo, Hio Sakai, Takuma Watabe, Daisuke Aoki, Hajime Sugita, Koichiro Mikami, Yuchen Mao, Akira Ishigami, Shotaro Nishitsuji, Takashi Kurose, Hiroshi Ito, Hideyuki Otsuka
Summary: Mechanochromic elastomers with force-induced cross-linking reactions and fluorescence properties have been successfully synthesized, demonstrating for the first time damage detection and changes in the mechanical properties of bulk elastomers induced by simple compression or extension.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Physical
Yoshifumi Abe, Takashi Kurose, Marcelo V. A. Santos, Yota Kanaya, Akira Ishigami, Shigeo Tanaka, Hiroshi Ito
Summary: The study investigated the influence of layer directions on the mechanical and shrinkage properties of 17-4PH stainless steel specimens fabricated by FDMet technology. It was found that specimens printed with their layer direction perpendicular to the tensile direction exhibited higher ultimate strengths, while those printed with their layer direction parallel to the tensile direction showed lower strength and strain at breakage. This behavior is attributed to stress concentration in oriented void defects present in the parts.
Article
Metallurgy & Metallurgical Engineering
Yutaro Sako, Takashi Kurose, Akira Ishigami, Hiroshi Ito
Summary: Aluminum flake-filled epoxy resin composites showed improved interfacial shear strength and tensile modulus with specific surface treatment, but the tensile strength did not increase, possibly due to the aggregation of aluminum flakes preventing sufficient shear force transfer.
JOURNAL OF THE JAPAN INSTITUTE OF METALS AND MATERIALS
(2021)
Article
Engineering, Multidisciplinary
Cheng-Ying Liu, Akira Ishigami, Takashi Kurose, Hiroshi Ito
Summary: UHMWPE/graphene nanocomposites synthesized by octa-screw extrusion exhibit significant improvements in strength, wear resistance, and thermal stability compared to pure UHMWPE, as well as increased hydrophilicity and absence of cytotoxicity, making them a potential candidate for joint replacement applications.
COMPOSITES PART B-ENGINEERING
(2021)
Article
Polymer Science
Yuchen Mao, Yuto Kubota, Jin Gong, Takashi Kurose, Akira Ishigami, Kota Seshimo, Takuma Watabe, Daisuke Aoki, Hideyuki Otsuka, Hiroshi Ito
Summary: The UV-cured mechanochromic polymer networks show enhanced mechanical properties, visualized stress effects, improved stress distribution, and clearer dissociation of dynamic covalent bonds. The quantitative analysis using achromatic gray-scale color space provides a more effective research method, offering insights into the performance of the materials.
Article
Polymer Science
Yutaka Kobayashi, Tsubasa Ueda, Akira Ishigami, Hiroshi Ito
Summary: This study examines how the initial crystal structure influences the hydrolytic degradation of polylactic acid (PLA) under accelerated conditions, finding that crystallinity alone does not determine the speed of hydrolysis.
Article
Polymer Science
Yuchen Mao, Yuto Kubota, Ruiqi Feng, Jin Gong, Akira Ishigami, Yutaka Kobayashi, Takuma Watabe, Daisuke Aoki, Hideyuki Otsuka, Hiroshi Ito
Summary: A covalent adaptable network was built using a mechanochromic cross-linker, which provided mechanical enhancement and strain-monitored function. The impact of cross-linking design on dynamic behavior and the toughening mechanism were investigated. The covalent adaptable network endowed P(SMA-DMAA) with self-reinforcing ability and shape-reprocess performance.
Article
Polymer Science
Yutaka Kobayashi, Akira Ishigami, Hiroshi Ito
Summary: Compared with polyolefins, polylactic acid (PLA) films used as single-use plastics have lower tear strength. This study investigated the relationship between tear strength and the higher-order structure of PLA films under different conditions. The films absorbed moisture or were annealed, leading to embrittlement and a decrease in the mobile amorphous (MAm) amount. The displacement until tearing decreased from 2.5 to 0.5 mm in both cases. However, there was a significant difference in the fracture morphology of the torn tip, depending on whether the film was crystallized or embrittled due to enthalpy relaxation.
Article
Polymer Science
Cheng-Ying Liu, Shota Mikoshiba, Yutaka Kobayashi, Akira Ishigami, Daisuke Yorifuji, Shin-ichiro Tanifuji, Hiroshi Ito
Summary: This study evaluated the resin filling, residence time distribution, and temperature profile of an octa-screw extruder experimentally and numerically. The results showed that the octa-screw extrusion exhibited better extrudate quality and a lower temperature profile compared to twin-screw extrusion.
Article
Polymer Science
Supaphorn Thumsorn, Wattanachai Prasong, Takashi Kurose, Akira Ishigami, Yutaka Kobayashi, Hiroshi Ito
Summary: This study fabricated commercial poly(lactic acid) (PLA) composites using FDM 3D printing and evaluated the effects of additives and bed temperatures on layer adhesion and mechanical performance. The results showed that the additives and bed temperatures significantly influenced the print quality and properties of the PLA composites.
Article
Polymer Science
Tongsai Jamnongkan, Nitchanan Intraramongkol, Wesarach Samoechip, Pranut Potiyaraj, Rattanaphol Mongkholrattanasit, Porntip Jamnongkan, Piyada Wongwachirakorn, Masataka Sugimoto, Hiroshi Ito, Chih-Feng Huang
Summary: This research focuses on the mechanical and electrical properties of polypropylene blended with recycled polypropylene. The results show that the addition of recycled polypropylene does not significantly affect the mechanical properties, but can improve the elongation at break. The electrical conductivity of the materials can be enhanced by adding carbon black, but it changes the mechanical behavior of the composites from ductile to brittle. DSC results also indicate that recycled polypropylene and carbon black can increase the crystallinity of polypropylene.
Article
Engineering, Manufacturing
Supaphorn Thumsorn, Wattanachai Prasong, Akira Ishigami, Takashi Kurose, Yutaka Kobayashi, Hiroshi Ito
Summary: This research studied the effects of ambient temperatures and crystalline structure on the interlayer adhesion and properties of thermoplastic FDM 3D printing. It was found that increasing the ambient temperature significantly improved interlayer bonding. In addition, PLA filament with high crystallinity has induced heat resistance and can successfully print at higher chamber temperatures.
JOURNAL OF MANUFACTURING AND MATERIALS PROCESSING
(2023)
Article
Materials Science, Paper & Wood
Tsubasa Ueda, Akihiko Nemoto, Akira Ishigami, Supaphorn Thumsorn, Yutaka Kobayashi, Hiroshi Ito
Summary: In this study, cellulose nanofibers (CNFs) were treated and used to reinforce polyvinyl alcohol (PVA) in the thermal imprinting process. The addition of CNFs improved the processability and replication quality of the thermal imprinting process.
Article
Chemistry, Multidisciplinary
Charinee Winotapun, Thidarat Makmoon, Chuanchom Aumnate, Dumrong Thanomjitr, Wuttipong Rungseesantivanon, Hiroshi Ito
Summary: Micropatterns were fabricated on polypropylene surfaces using hot embossing technique. The replication quality was evaluated based on the effective filling ratio. The results showed that the filling ratio increased with increasing embossing temperature and applied force. The effect of different melt flow indexes of polypropylene on the filling ratio was also investigated. Micropatterned polypropylene sheets demonstrated easy-opening properties for packaging applications.
Article
Engineering, Chemical
H. Ito, I Satoh, T. Saito, K. Yakemoto
Summary: In this study, a new polymer fabrication process called the Melt-Transcription Process was developed and its validity was experimentally discussed. By coating and compressing stages, precise microstructures can be created on the surface of polymer products. The experimental results showed that the Melt-Transcription Process can effectively transcribe microstructures on a large surface area with high transcription ratios under relatively low compression pressure.
INTERNATIONAL POLYMER PROCESSING
(2022)
