The effect of filler content and size on the mechanical properties of polypropylene/oil palm wood flour composites

The effect of filler content and size on the mechanical properties of a new type of wood-based filler, oil palm wood flour (OPWF), in polypropylene (PP) was investigated. Four sizes of OPWF filler at different filler loadings were compounded using a twin screw compounder. All sizes of filler showed a similar trend of declining mechanical properties with increasing filler content. In terms of size, the composites filled with larger-sized filler showed higher modulus, tensile and impact strengths, particularly at high filler loadings. The OPWF used in this study was not treated with any coupling agent.     

碱处理对抗菌导湿聚酯纤维性能的影响

讨论了使用碱处理方法对抗菌导湿涤纶进行亲水化改性的影响。用保水率和快干性能对纤维的吸湿、导湿性能的变化进行表征,探讨了碱处理对纤维的表面结构、吸水性、导湿性及抗菌性能的影响。结果表明,随着纤维横截面异形度的变化和碱处理浓度的增加,纤维表面产生微孔,纤维的吸湿性和织物的导湿性能都得到改善。     

二氧化硅对不饱和聚酯树脂浇铸体力学性能的影响

研究了SiO2对不饱和聚酯树脂（UPR）浇铸体拉伸性能的影响．用应变计电测法研究了SiO2填料对树脂浇铸体的拉伸变形特性和弹性模量的作用．运用变形功原理，对添加SiO2后材料的特性作了初步判断。结果表明：在所采取的实验条件下．填料SiO2的添加量对UPR的拉伸强度和弹性模量有显著的影响．其质量分数为8％时得到的强度比纯树脂试样提高了大约4．1％．但SiO2质量分数为8％时却是对应着材料的脆韧转变点。     

Effect of alkali treatment on the flexural properties of Hildegardia fabric composites

A uniaxial natural fabric of Hildegardia populifolia was treated with 5% sodium hydroxide solution for 1 h, and the resulting changes were analyzed by polarized and scanning electron microscopic techniques. The untreated and treated H. populifolia fabric was reinforced in epoxy and toughened with 10% polycarbonate. The variation of the flexural strength and flexural modulus with different fabric contents and fiber orienrations was studied. The effect of sodium hydroxide and a silane coupling agent on the flexural properties of the composite was also studied. It was observed that the flexural properties increased on alkali treatment and when the coupling agent was used. The morphology of the cryogenically fractured surfaces indicated good bonding between the matrix and the reinforcement when a coupling agent was used. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1297–1302, 2006     

Mechanical and Morphological Studies of Rubber Wood Sawdust-Filled UPR Composite Based on Recycled PET

Rubber wood sawdust fillers were mixed with unsaturated polyester matrix, which was prepared by recycling of PET waste from soft drink bottles, to prepare rubber wood sawdust/UPR composite. PET wastes were subjected to recycle by glycolysis and depolymerized to its monomer and dimmer. The glycolysed product was used to prepare unsaturated polyester resin. The FTIR analysis has been done on the resin and the glycolysed product. The resin then mixed with rubber wood sawdust fillers before and after alkali treatment with 10% NaOH. The effect of surface treatment and filler content on the mechanical properties and water absorption of the composite were studied. The tensile fractured surfaces of the composites were studied by Scanning Electron Microscopic (SEM) technique to investigate the interfacial bonding between the matrix and the filler. The results show that the tensile modulus increased with increasing filler contents. In addition, the results show that alkali treatment causes a better adhesion between rubber wood sawdust and UPR matrix and improves the mechanical properties.     

Bio-based compatibiliser enhancing the interface properties of CaCO3/recycled high-density polyethylene composites

The fabrication of composites of two or more materials with different polarities requires the use of compatibilisers to improve interface properties. However, most compatibilisers used for industrial production are derived from the cracking products of petroleum, which is a limited resource susceptible to price fluctuations and pollutes the environment. In this study, a new compatibiliser derived from renewable plant-oil-based products, ESO–G–OA, was designed and synthesized using epoxy soybean oil, oleic acid, and glycerol. Scanning electron microscopy results showed that ESO–G–OA can effectively improve the dispersion of CaCO₃ in a recycled high-density polyethylene (reHDPE) matrix and reduce the interfacial gap between the two phases. The analysis of the mechanical properties showed that the ESO–G–OA-modified composite has higher tensile and impact strength than unmodified samples. The ESO–G–OA modification improved the thermal stability and melt flow of the composite and reduced the energy consumption during processing. Moreover, the excellent compatibility of ESO–G–OA can improve the comprehensive properties of CaCO₃/reHDPE composites, compensating for the performance reduction caused by the multiple processing steps necessary to obtain reHDPE. This confirmed that ESO–G–OA has promising application prospects in the production of composites requiring compatibilisers.     

Unsaturated polyester resins based on recycled PET: Preparation and curing behavior

The oligomers obtained from the glycolysis of Poly(ethlene terephthalate) (PET) waste were reacted with maleic anhydride to form a series of unsaturated polyester resins. The obtained resin was used to study the curing reaction with styrene by differential scanning calorimetry. The heats of reaction for styrene and polyester vinyl groups were measured by extrapolating the experimental results. Various kinetic parameters have been obtained using Kissinger expressions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1052–1057, 2001     

Effects of a liquid metal co-filler on the properties of epoxy/binary filler composites

Liquid metals (LMs) with high fluidity and high thermal conductivity (TC) are receiving considerable attention in the research on thermal management polymer composites as alternatives to conventional rigid solid fillers or as co-fillers to overcome the trade-off between TC and composite processability at high filler loads. While most previous studies have investigated the effects of LM fillers in soft elastomeric matrices, their effects on the composite properties with rigid matrices, such as epoxy-based polymers, have not been discussed extensively. Herein, we investigated the effects of LM eutectic Ga-In (EGaIn) as a co-filler on the properties of rigid epoxy-based composites with a binary filler (Al₂O₃/EGaIn) system. The increase in the volume fraction of LM fillers significantly improves the processability of uncured precursor composites but markedly decreases the mechanical strength of the cured composites at their high loads—the latter effects have rarely been examined in previous studies. However, with adequate LM loads, the composites exhibited superior mechanical properties compared with the all-solid-filler system, withstanding a surprisingly high compressive load (~100 kN) under which the all-solid-filler system fractured. Furthermore, the epoxy/binary filler composites exhibited reasonably high TC values (~1 W/mK) comparable to that of commercial epoxy molding compounds, suggesting their potential applicability for electronic packaging.     

Physical and mechanical properties of unsaturated polyester resin matrix from recycled PET (based PG) with corn straw fiber

In this study, composites of unsaturated polyester resin (UPR), synthesized from recycled polyethylene terephthalate (PET), with 10 to 40% in volume of corn straw fiber (CSF), were elaborated and studied the effect of fiber content on their physical and mechanical properties. The content of cellulose (48.97%), hemicellulose (24.06%), and lignin (6.59%) were determined by chemical characterization of CSF. The characteristic bonds of the UPR were identified as a cross-linking network between the styrene monomer (ST) and the unsaturated polyester (UP) through FTIR. Two decomposition stages were observed by TGA–DTG. The results of physical and mechanical properties showed that as the fiber content increased in the UPR, the water absorption increased (0.6% to 2.56%), on the other hand, the density (1218.23 to 1150.28 kg/m³), flexural strength (50.58 to 26.98 MPa), flexural modulus (2.66 to 2.29 GPa), tensile strength (8.62 to 3.65 MPa), tensile modulus (1.18 to 0.43 GPa), and hardness (81.67 to 65.67 Shore D), they decreased. SEM analysis showed some defects in the fiber distribution in the UPR, which affected the mechanical properties of the composites. This research contributes to the development of new material from use of two waste materials for the benefit of the environment.     

The effects of alkali treatment on the mechanical and morphological properties of Pennisetum purpureum/glass-reinforced epoxy hybrid composites

The effects of alkali treatment on the mechanical properties, void contents and morphological of Pennisetum purpureum/glass-reinforced epoxy hybrid composites were studied. The composites were produced using the vacuum infusion method. Pennisetum purpureum fibres were treated with 5 and 10% dilute sodium hydroxide (NaOH) solution for 6?h. The epoxy resin was mixed with either the treated or untreated Pennisetum purpureum/glass fibres to a ratio of 70:30 (by volume). Tensile and flexural tests were performed on the composites in accordance with ASTM D638 and ASTM D790, respectively. The hybrid composites that contained 5% NaOH-treated Pennisetum purpureum fibres exhibited the greatest tensile and flexural strengths with lower void contents. Field-emission scanning electron microscopy fractography supported the findings showing lesser voids and fibre pull-outs suggesting good interfacial bonding between the matrix and reinforcement. The reduced of the void contents is suspected due to the reduced hemicellulose content within the treated Pennisetum purpureum fibre.     

Effect of alkali treatment on the caking properties of coal

Three weakly caking and non-caking high volatile bituminous coals from India were converted into good caking derivatives by treatment with alcoholic alkali at 250–300 °C and 22–25.5 MPa. These derivatives showed high Gieseler fluidities with wide plastic range and may be useful as additives to coals for oven charges. During alcoholic alkali treatment, the organic material of coal undergoes extensive degradation into relatively low molecular weight substances which possess sufficient thermal stability to maintain a fluid state on carbonization. Increasing the severity of alkali treatment produces a pitch-like material from coal, with a potential use as a binder for formed coke, carbon electrodes etc.     

抗静电聚酯的研制及性能分析

归纳分析国内外聚酯抗静电方法,采用复合抗静电剂（SRA）研制抗静电聚酯（SRPET）及纤维,探讨SRA的添加量、合成及纺丝工艺。纤维碱减量处理后,抗静电性能和手感均有所改善。     

Effect of inclusions and blending on the mechanical performance of recycled multilayer PP/PET/SiOx films

Extending the useful life of materials through recycling has proven to be an efficient means of reducing natural resource use and limiting the production of waste. In the case of polymer‐based materials, in general, and of packaging materials, in particular, material recovery is complicated by the presence of incompatible polymers, as well as a priori undesirable contaminants such as inorganic inclusions. This article investigated the recycling of multilayer packaging material systems, based on polypropylene and silicon oxide‐coated poly(ethylene terephthalate). In particular, the effect of a compatibilization of the blend using maleic anhydride‐grafted polypropylene on the mechanical properties of the recycled material was examined. Without a compatibilizer, and at low compatibilizer concentrations, the blend exhibits a coarse morphology and is brittle. At a concentration of 5% wt of the compatibilizer, a fine morphology is obtained, and the blend shows excellent ductility. Beyond this concentration, a brittle interphase forms between the blend constituents, with a corresponding decrease in ductility. These results were confirmed by a study of strain‐induced crystallization in the blend. Furthermore, the size of the SiO_x inclusions, resulting from the fragmentation of the oxide coating during reprocessing, had no detectable influence on the mechanical properties of the recycled blend, providing that their concentration is lower than 2 × 10⁻³. This study showed that a control of both the microstructure and interface properties considerably improves the mechanical properties of the recycled material, leading to high added‐value applications. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 910–918, 2000     

木粉/UPR复合材料的制备及力学性质研究

使用硅烷偶联剂表面处理的木粉(MW)和未改性木粉(UW)填充不饱和聚酯树脂(UPR)制备了复合材料.研究了表面改性处理和木粉粒径对复合材料力学强度的影响.结果表明,相对于未改性的木粉,用硅烷偶联剂处理的木粉对不饱和聚酯树脂有更强的增强作用,添加量为20(wt)％的MW/UPR复合材料的拉伸强度比纯UPR提高74.4％,...     

CaCO3对UPR浇铸体拉伸性能的影响

研究了CaCO3填料对不饱和聚酯树脂（UPR）浇铸体拉伸强度的影响，借助于应变片电测技术研究了CaCO3填料对树脂浇铸体的拉伸变形特性和弹性模量的作用。结果表明：在所毒取的实验条件下，填料CaCO3的添加量对UPR的拉伸强度和弹性模量有显著的影响，添加量为8％（质量分数）时试样的强度比纯树脂提高了大约54％，分析了填料CaCO3提高UPR拉伸强度的原因在于其显著提高了材料的韧性。     

Mechanical and open hole tensile properties of self‐reinforced PET composites with recycled PET fiber reinforcement

The tensile strength of notched composites is an important factor for composite structural design. However, no literature is available on the notch sensitivity of self‐reinforced polymer composites. In this study, self‐reinforced recycled poly (ethylene terephthalate) (srrPET) composites were produced by film stacking from fabrics composed of double covered uncommingled yarns (DCUY). Composite specimens were subjected to uniaxial tensile, flexural, and Izod impact tests and the related results compared with earlier ones achieved on srPET composites reinforced with nonrecycled technical PET fibers. Effects of open circular holes on the tensile strength of srrPETs were studied at various width‐to‐hole diameter (W/D) ratios of the specimens. In the open hole tensile (OHT) measurements bilinear (yielding followed by post‐yield hardening) stress–strain curves were recorded. The srrPET composites had extremely high yield strength retention (up to 142%) and high breaking strength retention (up to 81%) due to the superior ductile nature of the srrPETs, which induces plastic yielding near the hole thereby reducing the stress concentration effect. The results proved that srrPET composites are tough, ductile notch‐insensitive materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43682.     

Characterization and transport properties of ceramic filler incorporated natural rubber composites

Crystalline glass–ceramic fillers were prepared from calcium carbonate, silica, alumina, and calcium fluoride by heating and subsequent quenching in cold water. The fillers were incorporated into natural rubber (1,4-cis-polyisoprene) and the filled rubber composites were crosslinked with sulfur in the presence of different rubber additives. The unfilled and filled rubber composites were characterized. The transport properties of benzene, toluene, and p-xylene (BTX) through the rubber composites were studied in terms of sorption, diffusion, permeation, and mass transfer coefficients. The effect of the ceramic fillers on the mechanical, thermal and transport properties were studied. The sorption data at different temperatures were used for calculating activation energy of diffusion, permeation, free energy, and enthalpy of sorption. The BTX remained in the liquid state within the composite matrix as evident from negative ΔS. The diffusion coefficient (D) and mass transfer coefficient (k_mtc) of BTX decreased with the increase in filler loading. Accordingly, for the transport of BTX the unfilled rubber showed a D (D × 10⁷ cm²/s) and mass transfer coefficient (k_mtc × 10⁴ cm/s) of 5.67/3.97/2.96 and 7.71/7.08/7.04, respectively which decreased to 5.06/2.95/2.57 and 7.53/6.95/6.90, respectively for the composite containing 50 wt.% ceramic filler.     

Effect of flyash content,particle size of flyash,and type of silane coupling agents on the properties of recycled poly(ethylene terephthalate)/flyash composites

Recent time's polymer waste disposal is a challenging task as the quantity of polymer waste is increasing day by day. Here particulate composites have been developed from recycled poly(ethylene terephthalate) filled with flyash. Flyash of different particle sizes have been used, and effect of particle size and flyash content on the mechanical properties of composites has been analyzed. Tensile and flexural properties of the composites are found to increase with increase in filler content up to 15% and after that decreases due to the agglomeration of flyash particles. SEM studies also showed good dispersion at lower loadings. The use of silane coupling agents was found to increase the flyash/WPET interaction there by increase in mechanical properties is observed. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

无机填料的表面处理及其在导热天然橡胶复合材料中的应用

用季戊四醇、丙三醇和钛酸酯偶联剂分别对氧化铝、氧化镁和高岭土进行表面改性,并将改性填料填充天然橡胶(NR)制备了导热复合材料,考察了表面处理剂种类及其用量对无机填料的影响,并研究了季戊四醇改性氧化铝填充NR复合材料的硫化特性、物理机械性能和导热性能.结果表明,3种填料中季戊四醇的改性效果最好,且其用量为1.0～1.5份时对氧化铝的改性效果最佳;随着改性氧化铝填充量的增加,复合材料的最大转矩、300%定伸应力、拉伸强度和热导率均增大,当其用量为60份时,改性氧化铝填充NR复合材料的热导率比未填充NR复合材料提高了23.9%.     

Rubberwood–high-density polyethylene composites: Effect of filler size and coupling agents on mechanical properties

Composites were made from rubberwood in the form of fibers (RWF) and powder (RWP) and high-density polyethylene (HDPE). The RWP–HDPE composites showed higher tensile strength than those of the fibers. The inferior properties of the RWF-filled composites were believed to be attributed to the agglomeration of the fibers. Two types of coupling agents, that is, 3-(trimethoxysilyl)propyl methacrylate (TPM) and 3-aminopropyltriethoxysilane (APE), were employed in an attempt to improve the mechanical properties of the composites. The former was able to significantly improve the modulus of elasticity (MOE) and impact strength of the RWF-filled composites. Treatment with TPM resulted in the reduction of the tensile modulus and increase in the elongation at break (EB) for both RWF and RWP-filled composites. APE produced RWP-filled composites with a higher tensile strength and modulus. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1993–2004, 1998