The mechanical properties of polymer‐based composites are generally determined by the interfacial adhesion between the inorganic component and the polymer itself. In this work, high‐density ...polyethylene (HDPE) composites were prepared with polydopamine(PDA)‐modified short basalt fibers (D‐BF) as an inorganic filler, in which the interface between HDPE and D‐BF was mediated by maleic anhydride‐grafted polyethylene (PE‐g‐MAH) and maleic anhydride‐grafted poly(ethylene‐co‐octene) elastomer (POE‐g‐MAH). The adding mass ratio of both the compatibilizers had a significant effect on the mechanical properties of the prepared HDPE/D‐BF composites. When total 5 wt% of both PE‐g‐MAH and POE‐g‐MAH with a mass ratio of 1/3 was introduced, the tensile strength and elongation at break of the composite containing 2.5 wt% D‐BF reached 53.7 ± 0.8 MPa and 1174 ± 17%, respectively, about 73% and 157% higher than those of the pristine HDPE. Therefore, this work demonstrated a feasible way to prepare polymeric composites with high strength and high toughness via the dual‐compatibilizer and PDA modification of the fillers.
Polyamide is an engineering plastic, which has been widely used in industry and life. Polyamide 56, as a green and environmentally friendly bio‐based product, is gradually replacing traditional ...petroleum‐based products. However, in terms of auto parts, communication equipment, and mechanical products, a single polyamide monomer is difficult to meet the end‐use standard. EPDM‐g‐MAH (ethylene propylene diene monomer grafted with maleic anhydride) is melt blended with bio‐based polyamide 56 (PA56) in a twin‐screw extruder to obtain polyamide elastomers with different formulations. Subsequently, its morphology and structure, thermodynamic properties, crystallinity, and mechanical properties were analyzed. The test results show that the composites containing 10% EPDM‐g‐MAH have better impact resistance and thermal properties in the range of adding 0‑20 wt% EPDM‐g‐MAH. In the fracture morphology analysis, it is found that the interface between the rubber phase and the polyamide phase fused well, and the elastomer showed the ductile fracture.
The plasticized starch exhibits flexible properties, similar to that of elastomer. In this paper, thermoplastic starch acetate (TPAS) and maleic anhydride grafted ...polystyrene‐b‐(ethylene‐co‐butylene)‐b‐styrene (SEBS‐MAH) were used to toughen polypropylene (PP) through melt blending. It is found TPAS and SEBS‐MAH have a synergistic toughening effect on PP, especially the notched impact strength of PP/TPAS/SEBS‐MAH (70/15/15) blend is as high as 83.4 kJ/m2, but only 7.2 kJ/m2 of that for PP/TPAS/SEBS (70/15/15) blend. The structure‐property relationship of the PP/TPAS/SEBS‐MAH blends was investigated. Compared with PP/TPAS/SEBS (70/15/15) blend, the TPAS domains are dispersed homogeneously in the PP/TPAS/SEBS‐MAH (70/15/15) blend with the domain size of TPAS less than 0.2 μm. The incorporation of SEBS‐MAH not only improves the compatibility between PP and TPAS but also facilitates the formation of a core‐shell structure with TPAS as the core and SEBS‐MAH as the shell. Thus formed core‐shell particles play an important role in toughening PP. The spreading coefficient of the multiphase blend reveals that only when the SEBS‐MAH content is higher than TPAS, the core‐shell structure can be formed. Otherwise, TPAS and SEBS‐MAH will disperse separately and the toughness will not be improved. This work provides a new insight into polymer toughening with TPAS.
In the case of PP/TPAS/SEBS blends, SEBS and TPAS dispersed separately. For PP/TPAS/SEBS‐MAH blends, the size of TPAS was lower than that of TPAS in the PP/TPAS/SEBS blends at a given content. It indicates the compatibility between PP and TPAS was improved significantly due to the presence of SEBS‐MAH. Only when the content of SEBS‐MAH is not less than TPAS, a core‐shell structure with TPAS as the core and SEBS‐MAH as the shell can be formed, which plays an important role in PP toughening.
Hybrid nanomaterial-fibre-reinforced polymer composites show considerable promise but are often limited by the poor dispersion of the nanofillers, with filtering by the fibre weave being a common ...issue. Herein, a hybrid continuous glass fibre reinforced polymer (GFRP) was prepared based upon a polypropylene matrix, woven E-glass fibre (GF) and graphene nanoplatelets (GNP). The GNP flakes were melt-mixed with a polypropylene-graft-maleic anhydride (PP-MAH) compatibiliser and then melt-coated onto the GF mats, followed by layer-by-layer assembly using polypropylene films and coated fibre mats in a hot press. It was found that the stiffness and strength of the GFRP were increased by up to ∼3 GPa (25%) and ∼120 MPa (95%), respectively, by the addition of up to only ∼ 1.7 vol% of the GNP, to the composite. The experimental results enable us to extend our previous theory of mechanics of reinforcement by 2D materials to FRP. In-situ Raman band shift measurements on the flakes close to the glass fibres under strain found that the effective modulus of the flake is ∼130 GPa, indicating that a higher reinforcing efficiency of graphene was obtained in the FRP than in neat polymers due to improved local reinforcement effect of the matrix in the FRP.
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In this paper, poly(lactic acid) grafted with maleic anhydride (PLA‐g‐MAH) was prepared by melt grafting, and added into poly(lactic acid)/lemongrass fiber (PLA/LF) biocomposites after analyzing the ...chemical properties of LF. The effect of PLA‐g‐MAH on the properties of PLA/LF biocomposites was studied. Differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), scanning electron microscope (SEM) were used to characterize the crystallinity, isothermal crystallization behavior, thermal stability and microstructure of the biocomposites. In addition, the mechanical properties of biocomposites prepared by fused deposition modeling (FDM) 3D printing technology were also characterized. The results show that, the contents of cellulose, hemicellulose and lignin are 22.5%, 36.4%, and 22.8%, respectively in the composition of LF. With the addition of LF, the flexural modulus, crystallinity and crystallization rate of biocomposites are improved. After PLA‐g‐MAH was added, the crystallization rate of PLA is further slightly increased, but the crystallinity is not changed much. The mechanical properties of the PLA/LF biocomposites are improved to the greatest extent when 5 wt% PLA‐g‐MAH was added. PLA‐g‐MAH can significantly reduce the internal cavity and fiber peeling phenomenon, and there is no obvious gap between phases so that interface compatibility of PLA and LF is improved obviously.
At present, it is of great significance to develop an effective method of recycling cyclic olefin copolymers (rCOC) due to its increasing application. But, its poor toughness is still an important ...difficulty to limit its effective recycling. In this article, we introduced PA6 into the POE‐g‐MAH/rCOC composites. Because of the good compatibility of POE‐g‐MAH between PA6 and rCOC, it just led to an overall improvement in mechanical properties of PA6/POE‐g‐MAH/rCOC (45/15/40) composites. Its tensile strength reached 42.3 MPa, which was more than 41.9% compared with that of POE‐g‐MAH/rCOC composites. Its notched impact strength was 11.7 kJ/m2, which was higher than 875.0% compared with rCOC. Furthermore, the component of PA6 was wrapped by nonpolar rCOC and POE‐g‐MAH, resulting in a low water absorption rate (1.0%). So, the strength of the composites only dropped a little after water adsorption. In summary, the addition of PA6 helped the composites effectively utilize the toughness of POE‐g‐MAH. Thus, we developed an easy method to recycle rCOC and prepare the responding composites with high strength and toughness.
Polyamide‐6 was selected as the bridge between the rCOC resin and POE‐g‐MAH to prepare the responding polymer blends of PA6/POE‐g‐MAH/rCOC with high toughness and strength. Thus, rCOC could be effectively recycled.
This study constructs a flexible gradient foaming structure by changes the maleic anhydride-grafted styrene-ethylene/butylene-styrene (SEBS-g-MAH) content on the basis of a two-step foaming ...technique. The effects of SEBS-g-MAH content and its ratio in the first and second foaming steps on microstructure, compression, quasi-static burst, dynamic cushion, and thermal performance of flexible polyurethane foam composites are investigated. Results show that, SEBS-g-MAH content affects microstructure, compressive stress, burst strength, dynamic cushion and thermal performance. Gradient foaming improves compressive stress and quasi-static bursting strength by 3.81 and 1.56 times, respectively. The absorbed energy under dynamic impact of gradient foaming can be increased by 87% relative to that in one-step foaming. This study provides a new way approach to SEBS application, and serves as a new reference for designing of energy-absorbing foam composites by filler addition.
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•SEBS-g-MAH dispersed in PU foam to construct cushion structure by two-step foaming.•Gradient foaming structure is achieved by changes of SEBS-g-MAH content.•Gradient foaming improves compressive, bursting and dynamic cushion performance.•SEBS-g-MAH content affects microstructure, mechanical and thermal performance.
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•Nanoporous silicon (NPSi) adsorbent was firstly prepared by PV silicon waster.•Functionalized NPSi shows excellent Cd(Ⅱ) adsorption capacity of 210.01 mg/g.•Novel adsorbent is ...reversible and able to be reused without significant deterioration.•Kerf loss silicon waste is a potential substrate candidate for hybrid materials.
Recycling of kerf-loss slurry waste has become a meaningful and urgent issue in recent years. In this study, a novel hybrid material was prepared by Ag-assisted chemical etching kerf loss silicon waste and subsequently functionalized by a facile three-step graft process of 3-aminopropyltrimethoxy-silane, maleic anhydride, and ethylenediamine, named as EDA-MAH-APTES-NPSi, which could work as an effective adsorbent for removal of Cd(Ⅱ) from aqueous solution. The effect of initial pH, absorption duration, and metal ion concentrations on absorption performance were investigated. The adsorption equilibrium achieved after 120 min, the maximum adsorption capacity reached up to 210.01 mg/g and pH was at 5.5. The adsorption kinetic was fitted in the pseudo-second-order model and the Freundlich equation provided an accurate description for adsorption behavior. The XPS and FT-IR analysis manifested that Cd(Ⅱ) removal might be ascribed to the adsorption on the surface organic functional group by chemical chelating reaction and the ion exchange reaction. The EDA-MAH-APTES-NPSi maintained excellent adsorption capacity which decreased approximately 15.3 % (from 40.5–34.3 mg/g) after five successive regenerated cycles. The work confirms the potential of Cd(Ⅱ) removal from aqueous solution based on the modified NPSi and opens up a new way for recycling silicon cutting waste.
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•This study achieves the co-production of hydrochar and sugars from pineapple peel waste.•The Taguchi method and ANN optimize design parameters for sugar production.•Environmentally ...friendly alkaline ionized water decreases lignin content in pretreatment.•The highest sugar concentration after microwave-assisted heating hydrolysis is 52.85 g L−1.•Optimal hydrolysis can improve the higher heating value of hydrochar by up to 10.11 %.
This study uses a two-stage process to treat pineapple peel waste (PPW), including alkaline ionized water (AIW) pretreatment and microwave-assisted heating (MAH) hydrolysis. It also contains two objective functions: hydrochar yield and hydrolysis ratio. The experimental design utilizes the Taguchi method to determine optimal conditions by calculating the signal-to-noise ratio. The designed experimental results are used to predict optimal conditions through artificial neural networks (ANN). In the first step, AIW pretreatment reduces the lignin content of PPW by 17.5 % and increases the cellulose content by 14.8 %. SEM analysis reveals a roughening of its surface, while BET analysis identifies a slightly porous structure. These characteristics provide an increased efficiency for subsequent hydrolysis. In the second step, thermogravimetric analysis indicates that a substantial hemicellulose loss is observed when the hydrolysis concentration or temperature increases. This finding aligns with the ranking of factor impacts obtained from the Taguchi method. This study also demonstrates the potential of utilizing PPW for energy production. The hydrochar, hydrolyzed under optimal conditions, increases its calorific value by 10.11 % to 18.29 MJ‧kg−1, making it suitable for use as solid fuel. The hydrolysate has 52.85 g‧L-1 reducing sugar, which can be fermented to produce ethanol and is much higher than those reported in the literature. Through the Taguchi method and ANN, the optimal experimental factor combination prediction reveals the significant impact of acid hydrolysis compared to AIW pretreatment. The optimal hydrochar yield and hydrolysis ratio in the Taguchi method are 38.75 % and 63.62 %, respectively. In ANN, they are 41.51 % and 58.38 %, respectively, with relative errors of 7.08 % and 8.23 % compared to the experimental results. This research helps turn solid waste into green fuels and approach a circular bioeconomy.
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