Polymers

Research

11 pages, 3191 KiB

Open AccessArticle

Application of Eco-Friendly Waterborne Polyurethane Composite Coating Incorporated with Nano Cellulose Crystalline and Silver Nano Particles on Wood Antibacterial Board

by Liangsong Cheng, Shaobo Ren and Xiaoning Lu

Polymers 2020, 12(2), 407; https://doi.org/10.3390/polym12020407 - 11 Feb 2020

Cited by 63 | Viewed by 4919

Abstract

To endow wood plate with antimicrobial properties, waterborne polyurethane (WPU) coatings incorporated with nano cellulose crystalline (NCC) and silver nanoparticles (AgNPs) were prepared. AgNPs were obtained by the chemical reactions of silver nitrate solution and sodium borohydride solution. The scribe testing results showed [...] Read more.

To endow wood plate with antimicrobial properties, waterborne polyurethane (WPU) coatings incorporated with nano cellulose crystalline (NCC) and silver nanoparticles (AgNPs) were prepared. AgNPs were obtained by the chemical reactions of silver nitrate solution and sodium borohydride solution. The scribe testing results showed that the adhesion of the NCC-WPU composites was improved with the addition of NCC. The adhesion reached its peak when the amount of NCC added was 1%. Scanning electron microscopy (SEM) observation displayed that the NCC dispersed into the WPU without aggregation. NCC was well able to bind WPU and wood cell walls tightly together. Atomic force microscopy (AFM) and ultraviolet-visible (UV-vis) results revealed that WPU/NCC/AgNPs composites were homogeneous. This compatibility was also confirmed by transmission electron microscopy (TEM) analysis. The antibacterial property was improved too. When the adding amount of NCC was 0.5%, and the proportion of silver elements added was 5%, the antibacterial effect was at its best. As a comparison, the antibacterial effect of hybrid colloid without the addition of NCC was far less than that of including NCC. The WPU/NCC/AgNPs composite could be applied as an antibacterial coating in wood materials. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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15 pages, 3906 KiB

Open AccessArticle

All-Waste Hybrid Composites with Waste Silicon Photovoltaic Module

by Mihaela Cosnita, Ileana Manciulea and Cristina Cazan

Polymers 2020, 12(1), 53; https://doi.org/10.3390/polym12010053 - 31 Dec 2019

Cited by 1 | Viewed by 2848

Abstract

Nowadays, global warming, energy issues and environmental concern have forced energy production stakeholders to find new low carbon solutions. Photovoltaic technologies as renewable energy resources represent a competitive way for the transition from conventional fossil fuels towards a renewable energy economy. The highest [...] Read more.

Nowadays, global warming, energy issues and environmental concern have forced energy production stakeholders to find new low carbon solutions. Photovoltaic technologies as renewable energy resources represent a competitive way for the transition from conventional fossil fuels towards a renewable energy economy. The highest renewable energy systems (RES) market share is based on silicon photovoltaic (Si-PV). The installed RES have rapidly increased over the last two decades, but, after the end of their service life, they will be disposed of. Therefore, the constant increase of the installed RES has attracted the global concern due to their impact on the environment and, most of all, due to the content of their valuable resources. However, the rational management of RES waste has not been addressed so far. The paper represents an extension of a previous work focused on Si-PV recycling by developing all waste hybrid composites. The extension research conducted in this paper is related to the influence of Si-PV characteristics on the mechanical performances and water stability of the hybrid composites. All waste hybrid composites developed by embedding different Si-PV grain sizes were tested before and after water immersion in terms of mechanical strength, interfacial adhesion, crystallinity and morphology by scanning electron microscopy (SEM) analyses. The results revealed the better performance of such Si-PV composites compared to that of sieved composites even after long term water immersion. Therefore, high-content Si-PV hybrid composites could be developed without Si-PV powder sieving. Further on, all waste hybrid composites could be used as paving slabs, protective barriers for outdoor applications. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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16 pages, 4008 KiB

Open AccessArticle

Additive Manufacturing of Nerve Decellularized Extracellular Matrix-Contained Polyurethane Conduits for Peripheral Nerve Regeneration

by Yi-Wen Chen, Chien-Chang Chen, Hooi Yee Ng, Ching-Wen Lou, Yueh-Sheng Chen and Ming-You Shie

Polymers 2019, 11(10), 1612; https://doi.org/10.3390/polym11101612 - 4 Oct 2019

Cited by 34 | Viewed by 4093

Abstract

The nervous system is the part of our body that plays critical roles in the coordination of actions and sensory information as well as communication between different body parts through electrical signal transmissions. Current studies have shown that patients are likely to experience [...] Read more.

The nervous system is the part of our body that plays critical roles in the coordination of actions and sensory information as well as communication between different body parts through electrical signal transmissions. Current studies have shown that patients are likely to experience a functional loss if they have to go through a nerve repair for >15 mm lesion. The ideal treatment methodology is autologous nerve transplant, but numerous problems lie in this treatment method, such as lack of harvesting sites. Therefore, researchers are attempting to fabricate alternatives for nerve regeneration, and nerve conduit is one of the potential alternatives for nerve regeneration. In this study, we fabricated polyurethane/polydopamine/extracellular matrix (PU/PDA/ECM) nerve conduits using digital light processing (DLP) technology and assessed for its physical properties, biodegradability, cytocompatibility, neural related growth factor, and proteins secretion and expression and its potential in allowing cellular adhesion and proliferation. It was reported that PU/PDA/ECM nerve conduits were more hydrophilic and allowed enhanced cellular adhesion, proliferation, expression, and secretion of neural-related proteins (collagen I and laminin) and also enhanced expression of neurogenic proteins, such as nestin and microtubule-associated protein 2 (MAP2). In addition, PU/PDA/ECM nerve conduits were reported to be non-cytotoxic, had sustained biodegradability, and had similar physical characteristics as PU conduits. Therefore, we believed that PU/PDA/ECM nerve conduits could be a potential candidate for future nerve-related research or clinical applications. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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13 pages, 2437 KiB

Open AccessArticle

Mechanical, Thermal, and Electrical Properties of BN–Epoxy Composites Modified with Carboxyl-Terminated Butadiene Nitrile Liquid Rubber

by Xingming Bian, Rui Tuo, Wei Yang, Yiran Zhang, Qing Xie, Junwei Zha, Jun Lin and Shaojian He

Polymers 2019, 11(10), 1548; https://doi.org/10.3390/polym11101548 - 23 Sep 2019

Cited by 52 | Viewed by 4640

Abstract

Filled high thermal conductivity epoxy composite solves the problem of the low thermal conductivity of the epoxy resin itself, but the addition of the thermal conductive filler reduces the mechanical properties of the composite, which limits its application in the field of high [...] Read more.

Filled high thermal conductivity epoxy composite solves the problem of the low thermal conductivity of the epoxy resin itself, but the addition of the thermal conductive filler reduces the mechanical properties of the composite, which limits its application in the field of high voltage insulation. In this work, carboxyl-terminated butadiene nitrile liquid rubber (CTBN) was used to toughen the boron nitride-epoxy hybrid system, and the effects of different contents of CTBN on the mechanical properties, thermal conductivity, glass transition temperature, thermal stability, and dielectric properties of the composites were investigated. The results showed that when the content of CTBN was 5–15 wt.%, the CTBN formed a dispersed island structure in the epoxy resin matrix. The toughness of the composite increased by about 32%, the breakdown strength was improved, and the thermal conductivity was about 160% higher than that of pure epoxy resin. As the CTBN content increased, the glass transition temperature and thermal stability of the composite decreased and the dielectric constant and the dielectric loss increased. When the CTBN content is 10–15 wt.%, a toughened epoxy composite material with better comprehensive properties is obtained. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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14 pages, 4432 KiB

Open AccessArticle

Electroactive Composites with Block Copolymer-Templated Iron Oxide Nanoparticles for Magnetic Hyperthermia Application

by Shu-Chian Yang, Chun-Yu Chen, Hung-Yu Wan, Szu-Ying Huang and Ta-I Yang

Polymers 2019, 11(9), 1430; https://doi.org/10.3390/polym11091430 - 31 Aug 2019

Cited by 2 | Viewed by 3296

Abstract

Cancer has been one of the leading causes of human death for centuries. Magnetic hyperthermia is a promising technique to confine and control cancers. However, particles used in magnetic hyperthermia leaking from where the cancers are located could compromise human health. Therefore, we [...] Read more.

Cancer has been one of the leading causes of human death for centuries. Magnetic hyperthermia is a promising technique to confine and control cancers. However, particles used in magnetic hyperthermia leaking from where the cancers are located could compromise human health. Therefore, we developed electroactive iron oxide/block copolymer composites to tackle the leakage problem. Experimental results show that oleylamine-modified magnetic iron oxide (Fe₃O₄) particles and electroactive tetraaniline (TA) could be templated in the self-assembled microstructures of sulfonated [styrene-b-(ethylene-ran-butylene)-b-styrene] (S-SEBS) block copolymers. Various amounts of Fe₃O₄ particles and TA oligomer were incorporated in S-SEBS block copolymer and their electroactive behavior was confirmed by exhibiting two pairs of well-defined anodic and cathodic current peaks in cyclic voltammetry tests. The heating performance of the resultant TA/Fe₃O₄/polymer composites improved on increasing the added amount of Fe₃O₄ particles and TA oligomers. Both Fe₃O₄ and TA can contribute to improved heating performance, but Fe₃O₄ possesses a greater contribution than TA does. Hence, the main source for increasing the composites’ temperature is Neel relaxation loss from Fe₃O₄ magnetic particles. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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14 pages, 5354 KiB

Open AccessArticle

Mechanical Characterization and Impact Damage Assessment of Hybrid Three-Dimensional Five-Directional Composites

by Liwei Wu, Wei Wang, Qian Jiang, Chunjie Xiang and Ching-Wen Lou

Polymers 2019, 11(9), 1395; https://doi.org/10.3390/polym11091395 - 24 Aug 2019

Cited by 19 | Viewed by 3143

Abstract

The effects of braided architecture and co-braided hybrid structure on low-velocity response of carbon-aramid hybrid three-dimensional five-directional (3D5d) braided composites were experimentally investigated in this study. Low-velocity impact was conducted on two types of hybridization and one pure carbon fiber braided reinforced composites [...] Read more.

The effects of braided architecture and co-braided hybrid structure on low-velocity response of carbon-aramid hybrid three-dimensional five-directional (3D5d) braided composites were experimentally investigated in this study. Low-velocity impact was conducted on two types of hybridization and one pure carbon fiber braided reinforced composites under three velocities. Damage morphologies after low-velocity impact were detected by microscopy and ultrasonic nondestructive testing. Interior damages of composites were highly dependent on yarn type and alignment. Impact damage tolerance was introduced to evaluate the ductility of hybrid composites. Maximum impact load and toughness changed with impact velocity and constituent materials of the composites. The composite with aramid fiber as axial yarn and carbon fiber as braiding yarn showed the best impact resistance due to the synergistic effect of both materials. Wavelet transform was applied in frequency and time domain analyses to reflect the failure mode and mechanism of hybrid 3D5d braided composites. Aramid fibers were used either as axial yarns or braiding yarns, aiding in the effective decrease in the level of initial damage. In particular, when used as axial yarns, aramid fibers effectively mitigate the level of damage during damage evolution. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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13 pages, 2535 KiB

Open AccessArticle

3D Printing of Amino Resin-based Photosensitive Materials on Multi-parameter Optimization Design for Vascular Engineering Applications

by Yung-Cheng Chiu, Yu-Fang Shen, Alvin Kai-Xing Lee, Shu-Hsien Lin, Yu-Chen Wu and Yi-Wen Chen

Polymers 2019, 11(9), 1394; https://doi.org/10.3390/polym11091394 - 24 Aug 2019

Cited by 26 | Viewed by 4904

Abstract

Cardiovascular diseases are currently the most common cause of death globally and of which, the golden treatment method for severe cardiovascular diseases or coronary artery diseases are implantations of synthetic vascular grafts. However, such grafts often come with rejections and hypersensitivity reactions. With [...] Read more.

Cardiovascular diseases are currently the most common cause of death globally and of which, the golden treatment method for severe cardiovascular diseases or coronary artery diseases are implantations of synthetic vascular grafts. However, such grafts often come with rejections and hypersensitivity reactions. With the emergence of regenerative medicine, researchers are now trying to explore alternative ways to produce grafts that are less likely to induce immunological reactions in patients. The main goal of such studies is to produce biocompatible artificial vascular grafts with the capability of allowing cellular adhesion and cellular proliferation for tissues regeneration. The Design of Experimental concepts is employed into the manufacturing process of digital light processing (DLP) 3D printing technology to explore near-optimal processing parameters to produce artificial vascular grafts with vascular characteristics that are close to native vessels by assessing for the cause and effect relationships between different ratios of amino resin (AR), 2-hydroxyethyl methacrylate (HEMA), dopamine, and curing durations. We found that with proper optimization of fabrication procedures and ratios of materials, we are able to successfully fabricate vascular grafts with good printing resolutions. These had similar physical properties to native vessels and were able to support cellular adhesion and proliferation. This study could support future studies in exploring near-optimal processes for fabrication of artificial vascular grafts that could be adapted into clinical applications. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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12 pages, 4122 KiB

Open AccessArticle

Thermal Conductivity Enhancement Derived from Poly(Methyl Methacrylate)-Grafted Carbon Nanotubes in Poly(Methyl Methacrylate)/Polystyrene Blends

by Jaehyun Wie and Jooheon Kim

Polymers 2019, 11(8), 1347; https://doi.org/10.3390/polym11081347 - 13 Aug 2019

Cited by 24 | Viewed by 5133

Abstract

This paper presents a method to enhance thermal conductivity using poly(methyl methacrylate)(PMMA), polystyrene(PS) blends, and incorporation of multiwalled carbon nanotubes (MWCNTs). MWCNTs are selectively localized in PMMA phase to improve conductive properties. In addition, Surface of MWCNTs was treated with PMMA to enhance [...] Read more.

This paper presents a method to enhance thermal conductivity using poly(methyl methacrylate)(PMMA), polystyrene(PS) blends, and incorporation of multiwalled carbon nanotubes (MWCNTs). MWCNTs are selectively localized in PMMA phase to improve conductive properties. In addition, Surface of MWCNTs was treated with PMMA to enhance affinity between matrix and filler. PMMA grafting helps filler localization on matrix phase. Composites using two polymers enhanced thermal conductivity by ~11% compared with composites using only PS or PMMA. Also, PMMA grafting on the surface of MWCNTs enhanced thermal conductivity by ~13% compared with samples without PMMA grafting. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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12 pages, 3707 KiB

Open AccessArticle

Mechanical and Static Stab Resistant Properties of Hybrid-Fabric Fibrous Planks: Manufacturing Process of Nonwoven Fabrics Made of Recycled Fibers

by Yu-Chun Chuang, Limin Bao, Mei-Chen Lin, Ching-Wen Lou and TingAn Lin

Polymers 2019, 11(7), 1140; https://doi.org/10.3390/polym11071140 - 3 Jul 2019

Cited by 14 | Viewed by 5136

Abstract

With the development of technology, fibers and textiles are no longer exclusive for the use of clothing and decoration. Protective products made of high-strength and high-modulus fibers have been commonly used in different fields. When exceeding the service life, the protective products also [...] Read more.

With the development of technology, fibers and textiles are no longer exclusive for the use of clothing and decoration. Protective products made of high-strength and high-modulus fibers have been commonly used in different fields. When exceeding the service life, the protective products also need to be replaced. This study proposes a highly efficient recycling and manufacturing design to create more added values for the waste materials. With a premise of minimized damage to fibers, the recycled selvage made of high strength PET fibers are reclaimed to yield high performance staple fibers at a low production cost. A large amount of recycled fibers are made into matrices with an attempt to decrease the consumption of new materials, while the combination of diverse plain woven fabrics reinforces hybrid-fabric fibrous planks. First, with the aid of machines, recycled high strength PET fibers are processed into staple fibers. Using a nonwoven process, low melting point polyester (LMPET) fibers and PET staple fibers are made into PET matrices. Next, the matrices and different woven fabrics are combined in order to form hybrid-fabric fibrous planks. The test results indicate that both of the PET matrices and fibrous planks have good mechanical properties. In particular, the fibrous planks yield diverse stab resistances from nonwoven and woven fabrics, and thus have greater stab performance. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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14 pages, 5048 KiB

Open AccessArticle

Superhydrophobic Polytetrafluoroethylene/Heat-Shrinkable Polyvinyl Chloride Composite Film with Super Anti-Icing Property

by Zhiqing Jiang, Xueqin Wang, Huiying Jia, Yanfen Zhou, Jianwei Ma, Xinyu Liu, Liang Jiang and Shaojuan Chen

Polymers 2019, 11(5), 805; https://doi.org/10.3390/polym11050805 - 6 May 2019

Cited by 16 | Viewed by 3877

Abstract

Wind power generation is an environmentally friendly way to produce electricity, but wind turbine blades that are prone to freeze in winter will reduce the efficiency of the generator. Therefore, the preparation of anti-icing blades is important and essential. Herein, anti-icing polytetrafluoroethylene (PTFE)/heat-shrinkable [...] Read more.

Wind power generation is an environmentally friendly way to produce electricity, but wind turbine blades that are prone to freeze in winter will reduce the efficiency of the generator. Therefore, the preparation of anti-icing blades is important and essential. Herein, anti-icing polytetrafluoroethylene (PTFE)/heat-shrinkable polyvinyl chloride (HSPVC) composite film was prepared by depositing a PTFE coating on the surface of HSPVC film via vacuum thermal evaporation. HSPVC films were pretreated respectively by argon and carbon tetrafluoride (CF₄) plasma cleaning to introduce new groups and change their surface energy. After that, PTFE coating with a thickness of about 4 μm was deposited on the surface of HSPVC, obtaining a superhydrophobic surface with an apparent water contact angle of 150°. The results demonstrated that the breaking strength of the PTFE/HSPVC composite film using CF₄ plasma pretreatment decreased by only 3.47% after exposing to ultraviolet light with the power of 1000 W for 5 min, suggesting an excellent anti-ultraviolet property. Furthermore, compared with the pristine films, the PTFE/HSPVC composite films exhibited better adhesive strength, super anti-icing property even after 10 icing–deicing cycles, and excellent dynamic anti-icing performance. The PTFE/HSPVC composite film with good adhesive strength, anti-ultraviolet, and anti-icing properties has prospective applications in packaging of wind turbine blades. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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13 pages, 4361 KiB

Open AccessEditor’s ChoiceArticle

PP/TiO₂ Melt-Blown Membranes for Oil/Water Separation and Photocatalysis: Manufacturing Techniques and Property Evaluations

by Fei Sun, Ting-Ting Li, Haitao Ren, Qian Jiang, Hao-Kai Peng, Qi Lin, Ching-Wen Lou and Jia-Horng Lin

Polymers 2019, 11(5), 775; https://doi.org/10.3390/polym11050775 - 1 May 2019

Cited by 38 | Viewed by 6275

Abstract

This study aims to produce polypropylene (PP)/titanium dioxide (TiO₂) melt-blown membranes for oil/water separation and photocatalysis. PP and different contents of TiO₂ are melt-blended to prepare master batches using a single screw extruder. The master batches are then fabricated into [...] Read more.

This study aims to produce polypropylene (PP)/titanium dioxide (TiO₂) melt-blown membranes for oil/water separation and photocatalysis. PP and different contents of TiO₂ are melt-blended to prepare master batches using a single screw extruder. The master batches are then fabricated into PP/TiO₂ melt-blown membranes. The thermal properties of the master batches are analyzed using differential scanning calorimetry and thermogravimetric analysis, and their particle dispersion and melt-blown membrane morphology are evaluated by scanning electron microscopy. TiO₂ loaded on melt-blown membranes is confirmed by X-ray diffraction (XRD). The oil/water separation ability of the melt-blown membranes is evaluated to examine the influence of TiO₂ content. Results show that the thermal stability and photocatalytic effect of the membranes increase with TiO₂ content. TiO₂ shows a good dispersion in the PP membranes. After 3 wt.% TiO₂ addition, crystallinity increases by 6.4%, thermal decomposition temperature increases by 25 °C compared with pure PP membranes. The resultant PP/TiO₂ melt-blown membrane has a good morphology, and better hydrophobicity even in acetone solution or 6 h ultraviolet irradiation, and a high oil flux of about 15,000 L·m⁻²·h⁻¹. Moreover, the membranes have stabilized oil/water separation efficiency after being repeatedly used. The proposed melt-blown membranes are suitable for mass production for separating oil from water in massively industrial dyeing wastewater. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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10 pages, 2417 KiB

Open AccessArticle

Fabric Composites Reinforced with Thermally Bonded and Irregularly Aligned Filaments: Preparation and Puncture Resistant Performance

by Yu-Chun Chuang, Limin Bao, Mei-Chen Lin, Ting An Lin and Ching-Wen Lou

Polymers 2019, 11(4), 706; https://doi.org/10.3390/polym11040706 - 17 Apr 2019

Cited by 13 | Viewed by 4971

Abstract

This study proposes fabric composites with improved static and dynamic puncture via increasing a friction force to restrain the slide of filaments as well as the compression and abrasion between the fibers and the puncture probe. The the bi-layered shell layers of composite [...] Read more.

This study proposes fabric composites with improved static and dynamic puncture via increasing a friction force to restrain the slide of filaments as well as the compression and abrasion between the fibers and the puncture probe. The the bi-layered shell layers of composite fabrics are composed of aramid staple fibers and nylon staple fibers and a layer of low-melting-point polyester (LPET). The nonwoven layer consisting of recycled aramid and nylon staple fibers provides a shear effect to dissipate part of the puncture energy. Reinforcing interlayers include a woven fabric and PET filaments that are circularly aggregated between the surface layers, providing isotropic filament reinforcement and strengthening the resistance against the tip of the puncture probe. The reinforcing filaments may slide after the employment of needle punching, and to compensate for this disadvantage, the LPET layers are used to thermal bond the composite fabrics and the total thickness is controlled at 2 mm. The thermally bonded fabric composites are evaluated in terms of puncture resistance, thereby examining the effects of fabric structure and thermal bonding. According to the test results, the optimal composite structure is the sample N/L/W/F/L/N, which was reinforced by the LPET adhesive layer and irregularly aligned filaments. The sample which used the LPET adhesive layer had a positive influence on static puncture resistance and dynamic puncture resistance, preventing the slide of filaments, but the poor interfacial combination only contributed to limited reinforcement. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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11 pages, 6922 KiB

Open AccessArticle

Rheological Properties and Thermal Conductivity of Epoxy Resins Filled with a Mixture of Alumina and Boron Nitride

by Van-Dung Mai, Dae-Il Lee, Jun-Hong Park and Dai-Soo Lee

Polymers 2019, 11(4), 597; https://doi.org/10.3390/polym11040597 - 2 Apr 2019

Cited by 50 | Viewed by 6949

Abstract

Electronic packaging materials with high thermal conductivity and suitable viscosity are necessary in the manufacturing of highly integrated electronic devices for efficient heat dissipation during operation. This study looked at the effect of boron nitride (BN) platelets on the rheology and thermal conductivity [...] Read more.

Electronic packaging materials with high thermal conductivity and suitable viscosity are necessary in the manufacturing of highly integrated electronic devices for efficient heat dissipation during operation. This study looked at the effect of boron nitride (BN) platelets on the rheology and thermal conductivity of composites based on alumina (Al₂O₃) and epoxy resin (EP) for the potential application as electronic packaging. The viscosity and thermal conductivity of the composite were increased upon increasing filler content. Furthermore, thermal conductivity of the BN/Al₂O₃/EP was much higher than that of Al₂O₃/EP at almost the same filler loadings. These unique properties resulted from the high thermal conductivity of the BN and the synergistic effect of the spherical and plate shapes of these two fillers. The orientation of BN platelets can be controlled by adjusting their loading to facilitate the formation of higher thermally conductive pathways. The optimal content of the BN in the Al₂O₃/EP composites was confirmed to be 5.3 vol %, along with the maximum thermal conductivity of 4.4 W/(m·K). Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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13 pages, 4038 KiB

Open AccessArticle

Investigation of the Shear Thickening Fluid Encapsulation in an Orifice Coagulation Bath

by Xing Liu, Jun-Li Huo, Ting-Ting Li, Hao-Kai Peng, Jia-Horng Lin and Ching-Wen Lou

Polymers 2019, 11(3), 519; https://doi.org/10.3390/polym11030519 - 19 Mar 2019

Cited by 15 | Viewed by 3670

Abstract

The orifice coagulation bath method is proposed to encapsulate shear thickening fluid (STF) to form STF capsules, in an attempt to improve the combination of STF and the matrix as well as strengthen the flexibility and stability of the STF composites. By varying [...] Read more.

The orifice coagulation bath method is proposed to encapsulate shear thickening fluid (STF) to form STF capsules, in an attempt to improve the combination of STF and the matrix as well as strengthen the flexibility and stability of the STF composites. By varying the calcium chloride concentration (10, 20 mg/mL), sodium alginate concentration (5, 7, 10 mg/mL) and the surfactant dosage (10%, 20%, 30%), optimal preparation conditions were studied, considering the capsule strength and encapsulation rate. The capsules were also characterized using a scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and a thermogravimetric analyzer (TGA). The results show that the optimal solution for the preparation of the capsules is composed of 30% surfactant, 10 mg/mL mass concentration of CaCl₂, and 10 mg/mL mass concentration of sodium alginate. The rough surface and porous interior was observed by SEM. The average diameter of the capsules was 1.93 mm. The TGA curves indicate an improvement on the capsule thermal stability. This study thus provides a promising STF capsule preparation method. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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15 pages, 2515 KiB

Open AccessArticle

Fabrication of Hybrid Polymeric Micelles Containing AuNPs and Metalloporphyrin in the Core

by Yanxia Wang, Heng Yang, Si Chen, Hua Chen and Zhihua Chai

Polymers 2019, 11(3), 390; https://doi.org/10.3390/polym11030390 - 27 Feb 2019

Cited by 8 | Viewed by 3531

Abstract

Multi-structure assemblies consisting of gold nanoparticles and porphyrin were fabricated by using diblock copolymer, poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG-b-P4VP). The copolymer of PEG-b-P4VP was used in the formation of core-shell micelles in water, in which the P4VP block serves as the [...] Read more.

Multi-structure assemblies consisting of gold nanoparticles and porphyrin were fabricated by using diblock copolymer, poly(ethylene glycol)-block-poly(4-vinylpyridine) (PEG-b-P4VP). The copolymer of PEG-b-P4VP was used in the formation of core-shell micelles in water, in which the P4VP block serves as the core, while the PEG block forms the shell. In the micellar core, gold nanoparticle and metalloporphyrin were dispersed through the axial coordination. Structural and morphological characterizations of the complex micelle were carried out by transmission electron microscopy, laser light scatting, and UV-visible spectroscopy. Metalloporphyrin in the complex micelle exhibited excellent photostability by reducing the generation of the singlet oxygen. This strategy may provide a novel approach to design photocatalysts that have target applications in photocatalysis and solar cells. Full article

(This article belongs to the Special Issue Polymer Hybrid Composites)

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