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In order to improve the properties of bamboo‐plastic composites (BPCs), bamboo flour/high‐density polyethylene (HDPE) composites were reinforced with ultrahigh molecular weight polyethylene (UHMWPE). The effects of UHMWPE on properties of composites were studied. The crystallinity of composites decreased slightly. Compared with non‐UHMWPE added bamboo powder/HDPE composite, the composite with 6 wt % UHMWPE, showed decrease in water absorption to 0.41%, whereas its tensile strength and flexural strength increased to 34.51 and 25.88 MPa, respectively, a corresponding increase of 34.59 and 12.87%. The temperatures corresponding to initial degradation temperature (Tinitial) and maximum degradation temperature (Tmax) of the composite increased from 282.7 and 467.4 °C to 288.5 and 474.7 °C respectively. Scanning electron microscopic images showed that UHMWPE was well dispersed and fully extended as long fibers in the composite, forming a "three‐dimensional physically cross‐linked network structure," which contributed to the improved properties of the composites. © 2020 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48971. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Luffa sponge cell wall has a two-layer secondary wall. • 10%NaOH-20%CH 3 COOH treatment can help to obtain brilliant mechanical properties. • 10%NaOH-20%CH 3 COOH treatment made the luffa sponge fibrils arranged compactly. • 5%NaOH-5%H 2 O 2 treatment can help to control moisture regain. Abstract Luffa sponge (LS) is a resourceful natural plant fiber with polyporous structure, which can be effectively used for reinforcement of light weight composite materials. However, reduction in the moisture absorption tendency and enhancement in the mechanical properties of LS fiber bundles by chemical modifications are highly desirable in order to utilize LS as reinforcement material. In this study, three chemical treatments including the use of 5% sodium hydroxide and 5% hydrogen peroxide (5%NaOH-5%H 2 O 2), 10% NaOH and 20% acetic acid (10%NaOH-20%CH 3 COOH), and 18% NaOH and 1.6% carbamide (18%NaOH-1.6%CO(NH 2) 2) were used to modify the LS fiber bundles. And the effect of the three chemical treatment methods on the micro/nano structures, moisture absorption and mechanical properties of LS fiber bundles was investigated by using scanning electron microscopy (SEM), transmission electron microscopy (TEM), polarized light microscopy (PLM), fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis, moisture regain (MR) and tensile strength test. The results showed that the treatment with 10%NaOH-20%CH 3 COOH could significantly improve the mechanical properties of LS fiber bundles, the increase of the tensile strength was 121.3%. However, the treatment with 5%NaOH-5%H 2 O 2 could sharply decrease the mechanical properties of fiber bundles, the reduction of the tensile strength was 75.0%. Furthermore, the treatment with all the three above mentioned chemical combinations could reduce the moisture absorption of LS fiber bundles. The decrease in the moisture regain was found to be 29.0, 16.9, and 12.4%, respectively. [ABSTRACT FROM AUTHOR]

Highlights • The new processing method can make Luffa and EVA fibers be combined evenly and forming a 3D network structure. • The surface firmness of the novel luffa fiber cushion is only 25% of the jute cushion and 12% of 3D jute cushion. • The moisture dissipation of luffa fiber cushion is significantly better than those of the other plant cushions. Abstract The processing of mattress filling materials using natural plant fibers as matrix has increased dramatically in recent years. In this study, abundantly available luffa fibers and environment-friendly EVA resin were used as raw materials to produce luffa fiber cushion with the mass ratio of 1:1. The results demonstrate that the surface, core, and bottom firmness of luffa fiber cushion are smaller than those of jute cushion, 3D jute cushion, and palm cushion, especially its surface firmness is only 25% of the jute cushion and 12% of 3D jute cushion. The hygroscopicity of luffa fiber cushion is similar to that of palm cushion but its moisture dissipation is significantly better than those of the other three plant fiber cushions studied. [ABSTRACT FROM AUTHOR]

To promote the application of polyamide 6 (PA6) in wood–plastic composites, the negative effects associated with the thermal degradation of plant fibers must be overcome. In this study, waste bamboo fibers were subjected to pyrolysis and ball milling to afford nano bamboo-based biochar (BC), which was subsequently used as reinforcement to prepare PA6/BC nano composites by injection molding. In addition, the processing fluidity, water absorption, mechanical properties, and interface compatibility of PA6/BC composites were discussed. Results revealed that a BC content of less than 30 wt% is beneficial to improve the processing fluidity of the composites. With the increase in the BC content, the density of the PA6/BC composites gradually increased, while the water absorption of the PA6/BC composites gradually decreased, and the maximum decrease was 46%. Compared to that of pure PA6, the mechanical strength of PA6/BC composites was improved by the addition of BC, and the maximum tensile/flexural strength and modulus of PA6/BC composites increased by 41%/72% and 195%/244%, respectively. However, the impact strength decreased by 27%. After immersion treatment, the dimensional stability and mechanical strength of the composites decreased, while toughness improved. At a BC content of less than 40 wt%, BC particles exhibited good dispersibility and wettability in the PA6 matrix, and the rough surface and rich pore structure of BC rendered strong mechanical interlocking effects and good interface compatibility, thereby enhancing the mechanical properties of the composites. [ABSTRACT FROM AUTHOR]

In this study, we were concerned with the physical properties of carbon‐fiber‐ and pine‐cone‐fiber‐reinforced high‐density polyethylene prepared by compression molding. The resulting composites were characterized by scanning electron microscopy, X‐ray diffraction, Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and mechanical testing. The results indicate that the manufacturing properties of the composites were improved with the addition of carbon fibers. The FTIR results showed that the carbon‐fiber reinforcement of the composites was mainly achieved through physical effects. An appropriate content of carbon‐fiber addition improved the interface combination between the fibers and matrix; carbon fibers improve the water absorption of the material, and the relative crystallinity of the composite increased with increasing carbon‐fiber addition. With increasing carbon‐fiber content, the thermal decomposition temperature of the composites increased, and the thermal stability of the composites improved. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47304. [ABSTRACT FROM AUTHOR]

Poly(3-hydroxybutyrate–co–3-hydroxyvalerate) (PHBV) is a biodegradable polymer and has several potential applications. Herein, we have used a rich biomass resource, rice husk, to obtain rice husk nano-SiO2 (RHNS) and prepared RHNS/PHBV composites by using hot-press molding. The results showed that the amorphous nature of spherical nano-SiO2 particles with an average diameter of 40–80 nm was obtained. The tensile strength and flexural strength of the RHNS/PHBV-3 composite reached up to 23.515 and 75.669 MPa, respectively, corresponding to an increase of 33.65% and 15.54% as compared to pure PHBV. The enhanced mechanical properties of the RHNS/PHBV composite can be attributed to the uniform dispersion and strong interfacial bonding of RHNS with the PHBV matrix. In addition, the water absorption rate of the RHNS/PHBV composite increased from 0.26% to 0.35% and the water swelling ratio followed the given order in different directions: thickness > width > length. Furthermore, the initial degradation temperature and residual rate of combustion at 700 °C of the composites increased with higher content of RHNS, which represents the enhanced thermal stability of RHNS/PHBV composites. In summary, RHNS served as an excellent reinforcement and RHNS/PHBV composites have shown promising properties for various potential applications. [ABSTRACT FROM AUTHOR]

Luffa sponge (LS) is a resourceful material with fibro-vascular reticulated structure and extremely high porosity, which make it a potential candidate for manufacturing light mattress. In this study, two types of LS columns, namely high-density (HD) and low-density (LD) columns, were investigated as materials for filling the mattress. The results showed that the compressive strength of HD LS columns was significantly greater than that of LD LS columns. However, the densification strains of the two types of LS column were both in the range of 0.6 to 0.7. Besides, HD LS columns separately pressed to the smooth plateau region and the initial densification region exhibited a partial recovery of instant height when they were unloaded, and then both of them showed no more than 4.2% of height recovery after being allowed to rest at a constant temperature and humidity for 24 h. In contrast, when LD LS columns were compressed to the smooth plateau region, the height recovery was less than 1.62% compared to when they were pressed to the initial densification region, and that was more than 15.62%. Similar to other plant fibers used as mattress fillers, the two types of LS columns also showed good water absorption capacity—both of them could absorb water from as much as 2.07 to 3.45 times their own weight. At the same time, the two types of LS columns also showed good water desorption. The water desorption ratio of HD and LD LS columns separately reached 76.86 and 91.44%, respectively, after being let rest at a constant temperature and humidity for 13 h. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the natural Luffa vine (LV) fiber to be effectively used as cellulose fiber reinforcing material for lightweight and decay-resistance composite materials. The physical, chemical, thermal, and morphological properties of the LV fibers, together with their microstructure are investigated. The test results conclude that the LV density, microscopic characteristics, and mechanical properties show that this crop is a lightweight (200–550 kg/m3) natural fiber with a porous structure and a high specific modulus (1.18–2.04 MPa∙ m3/kg). The chemical, X-ray diffraction and the Fourier transform infrared spectroscopy analyses indicate that the LV has a high lignin content (25.18%) and a relatively high relative crystallinity (37.18%) of cellulose, and it contains saponins, which increase its erosion resistance and hardness. The thermogravimetric analysis reveals that the fibers can stand up to 315.4 °C. Moreover, due to their kinetic activation energy of 63.9 kJ/mol, they can be used as reinforcement materials in thermoplastic green composites with a working temperature below 300°. • Luffa vine (LV) have a multi-level porous structure and a high specific modulus. • The presence of saponins help LV develop corrosion-resistant composites. • The LV lignin is mostly guajacyl lignin and only a small amount of syringyl lignin. • The LV thermal properties meet to a working temperature of composites below 300 °C. [ABSTRACT FROM AUTHOR]

The main objective of this study was to improve the disadvantages including lower tear strength and shorter service life of commercial polyurethane viscoelastic foam (VF). In this study, waste, renewable luffa seed oil (LO) was directly used to modify polyurethane VF to prepare LO-modified polyurethane VF (LOVF). The results of testing of mechanical properties including tensile and tear strength indicated that the tensile and tear properties of LOVF gradually improved with the increase in added amount of LO. When the added amount of LO was 40%, the tear strength of LOVF increased by 97.2%, from 0.742 to 1.463 N cm−1; and the tensile strength increased by 49.3%, from 51.853 to 77.407 kPa. The results of dynamic thermomechanical analysis and nuclear magnetic resonance spectroscopy showed that the addition of LO did not result in the generation of new chemical bonds in LOVF, but the glass transition temperature of LOVF increased from 28.15° to 44°C with the increase in added amount of LO. This result is attributed to the fact that the fatty acid carbon chains in LO get physically cross-linked with the polyurethane molecular chains, which increases the degree of separation between hard and soft phases in LOVF. Thermogravimetric analysis presented that the thermal stability of LOVF was also improved. These results indicate that LO can effectively improve the tear resistance of VFs and extend their service life. Moreover, LOVF also shows good hygrothermal aging resistance and comfort level. All these favorable properties are beneficial to its broad range of practical applications. • Luffa seed oil-modified polyurethane viscoelastic foam (LOVF) has high tear strength. • The tear strength of LOVF-30 is increased by 79.11% compared to LOVF-0. • The high tear strength of LOVF is due to high phase separation and crosslink density. • The addition of luffa seed oil makes LOVF have good hygrothermal aging resistance. [ABSTRACT FROM AUTHOR]