Maximum Thermal Decomposition Temperature Research Articles

Tetrapanax papyriferus lignocellulosic skeleton aerogel enhanced with polyvinyl alcohol of high mechanical performance and thermal insulating

Biodegradable and renewable biomass aerogel has attracted significant attention because of its excellent characteristics. However, most aerogels were limited by poor mechanical strength and complex fabrication process. Herein, two delignified Tetrapanax papyriferus (TP) lignocellulosic samples (TP-SC, TP-FA/HAC) served as renewable porous skeletons with polyvinyl alcohol (PVA) modification to prepare high performance aerogels. The excellent pore structure facilitates the penetration of polyvinyl alcohol, which enhances the mechanical property and thermal stability of the resulting aerogel. The SC-8 h exhibited excellent mechanical strength with a bending stress of 102.9 MPa, 26.7 % increase in strain and 2.5 % in bending modulus compared to the TP-SC. The maximum thermal decomposition temperature of the FA/HAC-4 h was 358.6 °C, which was showed an outstanding thermal stability of the aerogel. Furthermore, these aerogels exhibited thermal insulating properties, and the maximum surface heating temperature after impregnation modification is lower than that of the original wood. This performance has a development prospect in the field of thermal insulation packaging and building structural materials. The high strength lignocellulosic skeleton aerogel could be prepared by a simple and effective strategy that preserved the original distinctive structure, offering a novel approach to the efficient utilization of TP.

Preparation and study of attapulgite reinforced PVA fiber with cross‐linking of boric acid

AbstractPolyvinyl alcohol (PVA) fibers were manufactured by gel spinning with reinforcing of attapulgite (ATT) and cross‐linking of boric acid (PVA/B/ATT fibers), in order to improve the mechanical properties. Furthermore, the final fibers were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectra (FTIR), differential scanning calorimetry (DSC), thermogravimetric analyzer (TGA), powder x‐ray diffraction (XRD) and tensile strength tester. In addition, when ATT amount was no more than 2.0 wt%, FTIR analyses suggested that the degrees of cooperation combining of ATT and boric acid with PVA macromolecules were enhanced. SEM images indicated that PVA/B/ATT fibers had smooth surfaces. DSC, TGA and XRD results illustrated that the melting temperatures and maximum thermal decomposition temperatures first increased and then dropped as the content of ATT increased. Moreover, mechanical properties results indicated that the optimal ATT amount was 2.0 wt%, and the tensile strength of PVA/B/ATT‐2 fiber reached the highest of 14.2 ± 0.3 cN/dtex. It was largely because that the cooperation combining of boric acid and ATT with PVA molecules improved the mechanical properties of PVA/B/ATT fibers.

Preparation of high transparency, thermal stability, flame retardant polymethyl methacrylate nanocomposite via gamma-radiation polymerization

Achieving flame retardancy and thermal stability in poly(methyl methacrylate) (PMMA) while maintaining its inherent high transparency presents a significant challenge. In this work, we successfully fabricated an exceptional composite (P-SiO2-PMMA) with high transparency, flame retardancy, and thermal stability using 60Co γ-ray irradiation-induced copolymerization of methyl methacrylate (MMA), 2-hydroxyethyl 2-methyl-2-propenoate phosphate (HEMAP), and nano-silica (SiO2). The impact of the HEMAP on the crystal, optical, thermal stability, and combustion behavior properties of P-SiO2-PMMA has been investigated. P-SiO2/PMMA forms a three-dimensional network cross-linked molecular chain structure, enhancing the thermal decomposition temperature (Tdi), maximum thermal decomposition temperature (Tmax), glass transition temperature (Tg), and reducing the coefficient of thermal expansion (CTE). HEMAP and SiO2 significantly enhance the flame retardancy of the material. The limiting oxygen index (LOI) value of transparent flame-retardant 20-P-SiO2/PMMA composite material increased from 17.5% for PMMA to 23.2%, with a 47.3% decrease in peak heat release rate (PHRR). The flame retardant mechanism was also investigated. This study offers a novel approach for the industrial application of high transparency, thermal stability, and halogen-free flame-retardant PMMA composite.

Polyphenolic truxillic acid crosslinked sodium alginate film with notable antimicrobial and biodegradable properties for food packaging

This work demonstrated an innovative antimicrobial and biodegradable food packaging film CBDA-10-SA which was prepared by crosslinking a natural polyphenolic truxillic acid (cyclobutane-dicarboxylic acid, CBDA-10) and sodium alginate (SA). The CBDA-10-SA film exhibited improved tensile strength (148 MPa) and UV shielding capabilities. The maximum thermal decomposition temperature was achieved of 249 °C. Compared to SA film, CBDA-10-SA showed increased antibacterial activities. In food packaging test, the CBDA-10-SA inhibited the rapid growth of potential of hydrogen (pH) value, slowed down the weight loss, reduced total plate count (TPC) value of pork, and delayed the spoilage process of pork. Notably, CBDA-10-SA displayed remarkable degradability in soil, with 60 % degrading in four weeks. In this study, CBDA-10-SA showed enhanced physicochemical and mechanical properties compared to traditional SA film. Those improvements make it anticipated to be used in not only food packaging but also mechanical, pharmaceutical, and agricultural fields.

Flame-Retardant Coating on Wood Surface by Natural Biomass Polyelectrolyte via a Layer-by-Layer Self-Assembly Approach

In this study, environmentally friendly and low-cost biomass materials were selected as wood flame retardants. Three polyelectrolyte flame-retardant coatings made from chitosan (CS), tea polyphenols (TP), soybean isolate protein (SPI), and banana peel powder (BBP) were constructed on wood surfaces by layer-by-layer (LBL) self-assembly. The results of SEM-EDS and FT-IR analyses confirmed the successful deposition of CS-TP, CS-SPI, and CS-BPP on the wood surface, and the content of N element increased. The TG results showed that the initial decomposition temperature and the maximum thermal decomposition temperature of the coated wood specimens decreased, while the char residue increased significantly. This is due to the earlier pyrolysis of CS-TP, CS-SPI, and CS-BBP. This shows that the three polyelectrolyte flame-retardant coatings can improve the thermal stability of wood. The combustion behavior of the wood specimen was observed by exposure to combustion; the coated wood could self-extinguish within a certain period of time after ignition, and the flame-retardant performance was improved to a certain extent. SEM and EDS characterization analyses of the carbon residue after combustion showed that the coated wood charcoal layer was denser, which could effectively block heat and combustible gas.

Preparation of short carbon fiber reinforced photosensitive resin and composite material properties study

AbstractLight‐curing rapid prototyping (SLA) has become an emerging technology in the manufacturing industry because of its high precision, rapid prototyping, and the ability to mold complex parts. To enhance the mechanical properties and thermal stability of its raw material photosensitive resin (PR), carbon fiber (CF) was surface modified by chemical oxidation and grafting of amino silane (KH550) to obtain KH550‐modified carbon fiber (ACF). Then, ACF was composited with photosensitive resin to obtain modified carbon fiber/photosensitive resin (ACF/PR) composites. The viscosities of ACF/PR composites, including the viscosity, curing shrinkage, mechanical properties, and thermal stability of the ACF/PR composites, were characterized. The results showed that KH550 was successfully grafted onto CF. When the addition of ACF in the composites was 0.6%, the tensile strength, elongation at break, and impact strength of ACF/PR reached 39.48 MPa, 20.32%, and 13.62 kJ/m2, which were 120%, 27.15%, and 154% higher than that of the pure resin; the thermal decomposition temperatures and the maximum thermal decomposition temperatures at 50% mass loss of ACF/PR increased to 457.66°C and 442.44°C at 50% mass loss, which is 3.95% and 3.63% higher than that of the pure resin. Currently, the composites have excellent strength, toughness, and thermal stability. This paper gives a cost‐efficient method for improving the functioning of PR.Highlights Mixed acid oxidation and amino silane modification of CFs. Preparation of modified CF/photosensitive resin composites. Composites with excellent mechanical properties and thermal stability.

Facile fabrication of lignin crosslinked hydrogel for cationic dye adsorption and antioxidant

Lignin, renowned for its abundance of hydroxyl groups, was utilized in three dimensions to fabricate a hydrogel matrix. In this study, the optimal conditions for the preparation of a lignin-crosslinked hydrogel and its potential for dye and antioxidant removal were investigated. The hydrogel was synthesized through a cross-linking reaction, with varying amounts of cross-linking agent (poly(ethylene glycol) diglycidyl ether) added to adjust for the lignin content. Chemical structure analysis of the lignin-crosslinked hydrogel was conducted using Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy, confirming successful hydrogel formation. Additionally, thermal analysis revealed an increase in the maximum thermal decomposition temperature with increasing cross-linker content. The lignin cross-linked hydrogel demonstrated a significantly higher swelling ability at pH 7 compared to pH 3. The dye adsorption capacity of the lignin-crosslinked hydrogel, which was evaluated using crystal violet (CV), showed a maximum adsorption capacity of 106 mg∙g-1. The CV adsorption behavior followed Freundlich isotherms and pseudo-first-order kinetics. Moreover, the lignin-crosslinked hydrogel exhibited notable antioxidant activity, which was attributed to the phenolic hydroxyl groups of lignin macromolecules. Therefore, lignin-crosslinked hydrogels prepared using cross-linking agents have promising application potential in various fields.

A comparative study on stabilizing and releasing thymol by pre-formed V-type starch and β-cyclodextrin

Cyclodextrins (CD) are well known to form host-guest assemblies with hydrophobic compounds. As a structural homologue, starch-guest inclusion complexes (ICs) have become promising in the food, agriculture, and pharmaceutical industries due to their low cost and versatility. This study compared the stabilizing and releasing abilities for thymol of three kinds of pre-formed V-type starch (Water-V, Salt-V, and Alkali-V) and β-CD. The loading efficiency for thymol decreased in the order of Water-V > Alkali-V > CD > Salt-V when removing the free thymol. Water-V, β-CD, and their ICs had better thermal stability with maximum thermal decomposition temperatures over 320 °C. Under non-cold chain daily storage conditions for 4 d, the percentage of thymol released from starch/CD-thymol ICs was 14% (Water-V), 35% (Salt-V), 34% (Alkali-V), and 43% (CD). The Water-V made ICs had good sustained release properties and long-term antibacterial activity, which kept strawberries fresh for 6 d without decay.

Influence of environmentally friendly curing system on properties of railway rubber pad

AbstractImproving the aging resistance and elasticity of rubber materials can increase the service life of rubber pads and reduce railway operation costs. The purpose of this work was to improve aging resistance, decrease compression set and ratio of dynamic stiffness to static stiffness (Rd/s) of railway rubber pads by using environmentally friendly accelerators N‐t‐butyl‐2‐benzothiazole sulfenimide (TBSI) and tetrabenzylthiuram disulfide (TBzTD). The influence of the curing system on the properties of rubber pads was assessed using multiple techniques. Compared to sulfur/tetramethylthiuram disulfide (TMTD) /N‐cyclohexyl‐2‐benzothiazole sulfenamide (CZ), compression set of S/TBSI/TBZTD decreased to 29.5% from 35.7%, retention of elongation at break after hot air aging increased to 77.7% from 66.1%, and Rd/s decreased to 1.82 from 1.85. Thermogravimetry (TG) and derivative thermogravimetry (DTG) analysis indicated that maximum thermal decomposition temperature of TBSI/TBZTD was higher, which was the reason for the good aging resistance and low compression set results. Rubber processing analysis (RPA) demonstrated that the loss factor of TBSI/TBZTD was smaller. The rubber cured by TBSI/TBZTD had a higher crosslinking density and smaller loss factor, which decreased the Rd/s. This study provides a reference for preparing of environmentally friendly rubber pads with a low Rd/s and long service life.

Structure and thermal stability of phosphochlorinated polybutadiene/carbon black composite synthesized via oxidative chlorophosphorylation reaction

The aim of the presented work was to obtain a new type of homogeneous composite based on an industrial polymer (polybutadiene, PB) and a well-known inexpensive filler (carbon black P-234, CB). For this purpose, the reaction of oxidative chlorophosphorylation (OxCh) was used. This makes it possible to introduce CB into the cross-linked structure of the modified polymer and ensure optimal distribution of the filler in it. The structure and thermal stability of the composite synthesized by the OxCh reaction were studied. Analysis of the composite by Fourier-transform infrared spectroscopy indicates a uniform distribution of carbon black in the network structure of the matrix and the physical interaction of the phases of the composite. Ultraviolet-visible spectrum data confirmed the improvement in light absorption in a wide range of the electromagnetic spectrum and the decrease in the optical band gap energy of the phosphochlorinated PB (PhPB) matrix with the addition of CB (Eg of PhPB = 3.25 eV; Eg of PhPB/CB composite = 2.28 eV). The influence of CB on the thermal stability of the PhPB matrix was studied using thermogravimetric and differential thermogravimetric analysis. After thermal analysis, the char yield for PhPB was 41 wt. %, and for PhPB/CB composite was 35.2 wt. %. Compared to PhPB, the increase in char yield, the decrease in maximum thermal decomposition temperature, and the high-integrated thermal decomposition temperature for the PhPB/CB composite show the improvement in the thermal stability of PhPB due to CB.

Impact of Chemical Properties Crumb Rubber with Different Waste Tire in Hot Mix Asphalt Design

The purpose of this research is to assess the impact of chemical properties of rubber crumbs for various types of waste tires mixed in design asphalt. This paper gives a scientific contribution of the chemical properties in relationship with the mix design asphalt. Many tires are replaced and dumped as waste in many parts of the world every year. This has created severe environmental problems such as pollution which governments of many nations spend a lot of budgets to manage every year. However, incorporating rubber crumbs as part of asphalt construction would help solve the environmental pollution problem in the world. The analysis is important because chemical properties such as Zn, Carbon, and Mg, have different characteristics that must be considered in making the best asphalt mix design. This would help to achieve alternate solutions. Furthermore, Utilizing XRD, FTIR, and TGA, the granules of several kinds of waste tire were examined. To achieve the best mix design for the asphalt, the results had many viewpoints. The TGA result demonstrated that all waste tires decomposed at the temperature of 500°C. However, the truck tire waste had the highest maximum thermal decomposition temperature of 587°C. The FTIR result showed that all the tire waste has similar chemical functional groups of polystyrene. The result of XRF showed that truck tire waste possesses the highest Zn content which is considered as dangerous element to the environment.

Preparation, stretch‐induced crystallization and thermo‐oxidative aging behavior of poly (lactic acid)/saponite grafted polystyrene nanocomposites films

AbstractIn this work, modified saponite (SAP‐g‐PS) was prepared by Pickering emulsion polymerization, and the optimum synthesis conditions of SAP‐g‐PS were investigated. Furthermore, SAP‐g‐PS was used as a reinforcing filler for poly (lactic acid) (PLA) and the mechanical properties results revealed that the elongation at break increased by 81.51% compared to pure PLA when SAP‐g‐PS was added up to 0.5 wt%. Scanning electron microscopy analysis showed that the fracture of PLA based nanocomposite films was ductile. The thermal analysis results showed that the maximum thermal decomposition temperature was increased from 352.19°C (PLA0, pure PLA film) to 361.63°C (PLA3, 0.5 wt% SAP‐g‐PS), and the crystallinity was increased from 18.2% (PLA0) to 31.3% (PLA3) at the traction ratio of 14. The stretch‐induced crystallization behavior of PLA based nanocomposites films was investigated under the conditions of the optimum blow molding process, and it was found that the elongation at break of PLA0 films increased from 25.8% to 37.4% and that of PLA3 was increased from 81.4% to 135.5% with the increase of the traction ratio, the crystallinity of both films showed an increasing trend, which indicated that the presence of the tensile flow field improved the orientation of the PLA, and increased its crystallization and mechanical properties. The thermo‐oxidative aging kinetics of PLA based nanocomposites films with different additions of SAP‐g‐PS were investigated by thermo‐oxidative aging experiments, and the lifetime of the films were predicted by the Arrhenius equation, which showed that the addition of SAP‐g‐PS effectively improved the lifetime of PLA based nanocomposites films.

The influence of phenolic resin modified by cardanol on improving the processability of PVC

Polyvinyl chloride (PVC) is a kind of plastic widely used in different industries, and it is a hard and brittle polymer that requires the use of plasticizers to improve processability. Phthalates are small molecule plasticizers of PVC, which are easy to volatilize and migrate while improving the processing properties of PVC. We propose alternatives based on phenolic resin prepolymer modified by cardanol (CPF), which were added to PVC as reactive plasticizer and can improve the processability of PVC. The effects of CPF on the rheological properties and migration resistance of plasticized PVC were studied, and the changes in the physical properties of blends were also discussed. The results showed that the viscosity of PVC melt can be reduced by two orders of magnitude by adding 30 wt% prepolymers at 180°C compared with PVC without CPF, which indicated that CPF can be used to reduce the processing temperature of PVC. The test results of migration resistance showed that the mass loss rate of the blend with 30 wt% prepolymers was less than 1 wt% after curing, however, the mass loss rate of the blend with 30 wt% dioctyl phthalate (DOP) was more than 12% after 5 days of testing. When the PVC/CPF mass ratio was between 60/40-70/30, the maximum values of tensile strength and elastic modulus are 64.4 MPa and 3.2 GPa, respectively, which showed the addition of CPF could significantly improve the tensile strength and elastic modulus of the blend system compared with PVC without CPF. Especially, the thermal stability of CPF is better than that of DOP, CPF exhibits the maximum thermal decomposition temperature (410°C), higher than that of DOP (170°C), which can adapt to higher processing temperature.

Eco-Friendly Cellulose-Based Nonionic Antimicrobial Polymers with Excellent Biocompatibility, Nonleachability, and Polymer Miscibility.

This study aims to prepare natural biomass-based nonionic antimicrobial polymers with excellent biocompatibility, nonleachability, antimicrobial activity, and polymer miscibility. Two new cellulose-based nonionic antimicrobial polymers (MIPA and MICA) containing many terminal indole groups were synthesized using a sustainable one-pot method. The structures and properties of the nonionic antimicrobial polymers were characterized using nuclear magnetic resonance hydrogen spectroscopy (1H NMR), infrared spectroscopy (FTIR), wide-angle X-ray diffractometry (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), gel chromatography (GPC), and other analytical techniques. The results showed that microcrystalline cellulose (MCC) molecules combined with indole derivatives through an esterification reaction to produce MICA and MIPA. The crystallinity of the prepared MICA and MIPA molecules decreased after MCC modification; their morphological structure changed from short fibrous to granular and showed better thermal stability and solubility. The paper diffusion method showed that both nonionic polymers had good bactericidal effects against the two common pathogenic bacteria Escherichia coli (E. coli, inhibition zone diameters >22 mm) and Staphylococcus aureus (S. aureus, inhibition zone diameters >38 mm). Moreover, MICA and MIPA showed good miscibility with biodegradable poly(vinyl alcohol) (PVA), and the miscible cellulose-based composite films (PVA-MICA and PVA-MIPA) showed good phase compatibility, light transmission, thermal stability (maximum thermal decomposition temperature >300 °C), biocompatibility, biological cell activity (no cytotoxicity), nonleachability, antimicrobial activity, and mechanical properties (maximum fracture elongation at >390%).

Preparation, characterization and in vitro digestion of octenyl succinic anhydride-modified porous starch with different degrees of substitution

Octenyl succinic anhydride modified porous starch (OSA-PS) with degrees of substitution (DS) from 0.0123 to 0.0427 were prepared by aqueous phase method. From SEM, PS had a porous structure which showed a rough and corrosive surface after esterification with OSA. FT-IR revealed the characteristic peaks of OSA-PS at 1725 cm−1 and 1570 cm−1. From 1H NMR spectra, OSA-PS displayed extra chemical signal peaks at 0.85 ppm, 1.25 ppm and 1.96 ppm. These results fully demonstrated that OSA groups were successfully grafted onto PS. Furthermore, as DS increased, the specific surface area (5.6464 m2/g), pore volume (0.9959 × 10−2 cm3/g) and methylene blue adsorption capacity (24.3962 mg/g) of OSA-PS reached the maximum, while its relative crystallinity (26.8112 %) and maximum thermal decomposition temperature (291.96 °C) were the minimum. In vitro digestion studies showed that with the increase of DS, OSA-PS' contents of rapidly digestible starch and slowly digestible starch decreased from 9.06 % to 6.27 % and 28.38 % to 14.61 %, respectively. In contrast, its resistant starch had an increase in content from 62.56 % to 79.12%. The results provided an effective method for obtaining a double-modified starch with high specific surface area and anti-digestibility, thus broadening the industrial application of starch.

Protein modified cellulose nanocrystals on reinforcement and self-driven biodegradation of aliphatic polyester

Due to the highly environment-dependent biodegradation and uncontrolled degradation period, the long-run feasibility and effectiveness of biodegradable polymers are extensively questioned to solve plastics waste accumulation and pollution problems. This work physically incorporated lipase PS from Burkholderia cepacian on cellulose nanocrystals (CNC) and embedded it in polycaprolactone (PCL) to construct stable and controllable interfacial microenvironment between CNC and PCL for the reinforcement and controllable self-driven biodegradation. The physical adsorption of lipase PS on CNC was studied by monitoring the surface charge and particle size. FT-IR spectra confirmed the successful incorporation of lipase PS and CNC. Compared with CNC, protein-modified CNC had a higher maximum thermal decomposition temperature of 345 °C and lower interfacial tension of 11 mN/m with PCL which provided PCL composites with higher nucleation efficiency and tensile elongation of 1086 % at break. In addition, only 0.67 % embedded lipase PS completely hydrolyzed PCL membranes in <140 h. The post-compression molding at 80–100 °C had negligible influence on the lipase activity, which indicated that CNC could protect the lipase from inactivation in polymer extrusion and compression. This work also highlighted protein-modified CNC as a new technology for polymer reinforcement.

Preparation of nano-Ag-Bi2WO6–TiO2/starch bionanocomposite membranes and mechanism of enhancing visible light degradation of ethylene

Ag–Bi2WO6–TiO2 (ABT) ternary composite photocatalyst was prepared using solvothermal and surface deposition method. Then, the nano photocatalyst was doped into the starch film liquid through internal loading method, and finally, ABT/starch composite film was constructed using tape casting method for visible light catalytic degradation of ethylene. Characterize and analyze the structure and physical properties of nano ABT/starch composite membranes prepared with different ABT loading amounts, and optimize the reaction conditions (ABT addition amount, light intensity, initial concentration of ethylene) on the visible light catalytic degradation performance for ethylene of the composite membrane. The results show that the nano ABT particles and starch molecules have good biocompatibility, and they can be well fused to form a film, without changing the crystal structure of ABT and generating other chemical bond. The results of photocatalytic degradation of ethylene showed that when the loading amount of ABT was 5 wt%, the light intensity was 60.5 mw/cm2, and the initial concentration of ethylene was 0.15 mg/L, the ABT/starch film had the best ethylene degradation performance, with a K′ value of 5.6111 × 10−4 min−1, which is 17.9 times that of the blank starch film. Under the optimal preparation conditions, the thickness, tensile strength, elongation at break of the starch composite film is 168.33 μm, 5.01 Mpa, 32.4%, respectively, and the maximum thermal decomposition temperature is 320.5 °C, which meets the requirements for food packaging materials. After 4 cycles, the catalytic degradation of ethylene by starch composite membrane only decreased by 13.98%, indicating good reusability.

Effect of Chemical Treatment on Rice Straw Fiber Surface and Properties of Straw/Polylactic Acid Composites

ABSTRACT In this work, rice straw fibers were modified using NaOH, KBM-403, and tetraethyl orthosilicate (TEOS), and the changes in the surface groups of the straw fibers before and after the modification were analyzed by infrared testing. Straw/polylactic composite were prepared by hot pressing, and the effects of the modifiers used on the properties of these blends were studied by conducting mechanical and thermal performance tests. The results showed that the tensile strength of the straw fiber composites modified by NaOH and KBM-403 increased by 20% and 21.2%, respectively, compared with that of the unmodified composite, whereas the tensile strength of the TEOS-modified fiber did not increase significantly. The flexural strengths of the composites increased by 10.2%, 11.1%, and 13.2%. The impact strength increased by 38.5%, 7.6%, and 7.6%. The results of thermal analysis show that initial and maximum thermal decomposition temperatures of the composite materials increased, indicating that the modified composite materials had a higher thermal stability. These blends are a kind of potential material for structural applications such as interiors, drywell and partitions for furniture.

Preparation and Characterization of Modified GO/Waterborne Polyurethane/Polyvinyl Alcohol Nanofibers

To strengthen waterborne polyurethane/polyvinyl alcohol nanofibers which is a potential filtering material, in this work, modified graphene oxide (GO) was mixed into the solution of waterborne polyurethane and polyvinyl alcohol. By electrospinning, the modified GO/waterborne polyurethane/polyvinyl alcohol nanofibers were prepared. The composite nanofibers showed good thermal behavior due to the addition of modified GO. The results show that the maximum thermal decomposition temperature of nanofibers film increased by 26 °C when the content of modified GO was 0.4% in the composite nanofiber. At the same time, the tensile property of the composite nanofiber was improved and a better mechanical behavior appeared when using a rotating way to fabricate the nanofibers, which the value of tensile length at break in the radial direction and tensile strength at break in arc direction rose by 68.7% and 38.7% separately.

Enhanced Thermal Conductivity of Nanodiamond Nanosheets/Polymer Nanofiber Composite Films by Uniaxial and Coaxial Electrospinning: Implications for Thermal Management of Nanodevices

Nanotechnology is gradually applied to the preparation of heat dissipation materials with the miniaturization of electronic devices. Electrospinning technology has received extensive attention due to its unique advantages in constructing continuous nanofibers. In this work, uniaxial-polyvinyl alcohol/nanodiamond (U-PVA/ND) and coaxial-polyvinyl alcohol/nanodiamond (C-PVA/ND) composite fiber films with different microscopic morphologies were constructed by uniaxial and coaxial electrospinning. The results show that the thermal conductivities of U-PVA/ND and C-PVA/ND composite fibers with 60 wt % ND content are 71.3 and 85.3 W m–1 K–1, respectively, which are 171.2 and 205.1 times greater than that of the pure PVA fiber film. In addition, the maximum thermal decomposition temperature (Tmax) and volume resistivity of the C-PVA/ND composite fiber film were 364.3 °C and 2.29 × 1015 Ω·cm, respectively, demonstrating the excellent thermal stability and electrical insulation of the composite fiber film. This experiment results provide strong evidences of electrospinning technology for the preparation of highly thermally conductive composites. So, thermally conductive films can be used as the outer layer of electronic components to accelerate their heat dissipation and extend their service life.