High-value utilisation of ceramic waste powder in PVC-based composite and basalt fibre reinforcement effect on its performance

Herein, ceramic waste (CW) powder and basalt fibre (BF) were used as inorganic filler and reinforcement, respectively, to prepare polyvinyl chloride (PVC)-based composites. The influence of the CW content on the rheological and mechanical properties of PVC-based composites was studied to attain a proper CW filling content. Besides, the effects of BF addition on the mechanical properties, water resistance, thermal conductivity and thermal stability of the BF/CW/PVC composites were investigated. The results show that although plasticising time is prolonged as the CW filling content increases, the CW/PVC composites still have good processability under high-filling content of 50 wt% CW. The addition of 10 wt% BF improves the mechanical properties of the CW/PVC composite. The BF/CW/PVC composites have good water resistance and thermal insulation performances. The CW filling powder and BF significantly improve the thermal stability and enhance the deformation resistance and storage modulus of the composites. This work provides a high-value utilisation method for recycling CW.     

石墨烯/聚乙烯高性能复合材料的制备与性能表征

采用液相超声分散热压制备了氧化石墨烯/聚乙烯(GO/PE)复合材料,研究了GO的微观结构,及GO/PE复合材料的热稳定性、力学性能、显微硬度及耐摩擦性能。对比纯PE与GO/PE复合材料可以发现,添加GO,复合材料的热稳定性、力学性能、显微硬度和耐磨性能有了明显提高,显微硬度的增加减少了PE及其复合材料与金属表面的有效接触面积,提高了材料的摩擦性能。     

PE-HD/BF/PE-g-MAH复合材料的力学性能和热性能

采用10 %（质量分数,下同）的NaOH碱溶液处理竹纤维（BF）,用双螺杆挤出和注射成型的方法制备了高密度聚乙烯（PE-HD)/BF和PE-HD/BF/马来酸酐接枝聚乙烯（PE-g-MAH）复合材料,用扫描电子显微镜和热失重分析仪观察和表征了材料的形貌和热稳定性, 测试了力学性能、流动性能和热变形温度。结果表明,碱处理可提高BF的热稳定性;碱处理的BF使PE-HD的刚性、弯曲强度和热变形温度提高,但导致拉伸强度、冲击韧性、熔体流动性和热稳定性下降;添加PE g MAH能改善BF与PE-HD基体之间的界面结合,添加5 % PE-g-MAH可同时提高PE-HD/30 % BF复合材料的拉伸、弯曲和冲击性能以及热稳定性和热变形温度,而且复合材料具有较好的流动性,可满足注射成型的要求。     

Influence of organic montmorillonite nanoparticles on the microstructures and thermal and tribological properties of polyethersulfone and polytetrafluoroethylene composites

Because of high wear rate and low thermal deformation temperature, the generalization and application of polytetrafluoroethylene (PTFE) in the field of tribology is restrained to a certain extent. In order to improve the wear resistance and thermal stability of this self‐lubricating polymer, organic montmorillonite (OMMT) nanoparticle reinforced polyethersulfone (PES) and PTFE ternary composites were prepared by the cold molding and vacuum sintering technology. The effects of sodium montmorillonite (Na‐MMT) and OMMT on the microstructures, thermal stabilities and tribological properties of PTFE composites were comparatively studied. The results show that the thermal stability of the PES/PTFE composites is clearly improved by the incorporation of OMMT nanoparticles. Not only the friction coefficients but also the wear rates of OMMT/PES/PTFE composites are less than those of Na‐MMT/PES/PTFE composites under identical tribological tests. Of all these PTFE composites, the PES/PTFE composite containing 10.0 wt% OMMT nanoparticles exhibits the best friction and wear properties (μ = 0.14, k = 5.78 × 10^?15 m³ N^–1 m^?1). This can be attributed to the existence of a polymer multicomponent layer consisting of PTFE, PES and OMMT on the composite surface as well as the formation of uniform PTFE transfer film on the worn surfaces of metal counterparts.     

铝酸酯增容改性竹粉对PBAT/BF复合材料性能的影响

利用异相捏合双螺杆挤出机，将铝酸酯处理前后的竹粉（BF）分别与聚对苯二甲酸?己二酸丁二醇酯(PBAT)共混，制得PBAT/BF复合材料。采用万能试验机、热重分析仪、扫描电子显微镜对PBAT/BF复合材料进行力学、热学性能和微观结构的表征。结果表明，BF表面经铝酸酯处理后，PBAT/BF复合材料的热稳定性和力学性能均得到改善，当铝酸酯添加量为1 %（质量分数，下同）时，PBAT/BF复合材料的冲击强度由6.7 MPa增加到9.5 MPa，提高了42 %，且断裂伸长率提高了92.7 %。     

二氧化硅气凝胶隔热复合材料的高温疏水改性及失效机制

SiO₂气凝胶隔热复合材料已经广泛应用于航空航天、石油化工等隔热保温领域,通过疏水改性可大幅拓展其应用场景。为了使SiO₂气凝胶隔热复合材料在更高温度仍保持良好的疏水性能,采用聚硅氧烷改性硅酸盐涂料对SiO₂气凝胶隔热复合材料进行表面刷涂疏水改性,然后研究了涂层厚度对裂纹扩张的影响以及涂层在高温下疏水性能的失效机制和刷涂改性前后复合材料的耐磨损性能。结果表明,当涂层厚度大约为13 μm时,所制备的涂层表面无裂纹,接触角可达(113±2)°,经450 ℃高温热处理1 800 s后接触角依然可以保持在105°左右,表现出良好的热稳定性,同时涂层显著提高了复合材料的耐磨损性能。     

聚乳酸/竹粉复合材料的改性及性能研究

采用甲基丙烯酸缩水甘油酯接枝乙烯辛烯共聚物（POE?GMA）作为相容剂，TPW604作为润滑剂，利用XSS?300转矩流变仪熔融制备聚乳酸（PLA）/竹粉（BF）复合材料。通过热失重、拉伸、冲击 、扫描电子显微镜、旋转流变等方法研究BF、POE?GMA、TPW604添加量对PLA/BF复合材料性能的影响。结果表明，当BF添加量为35 %、POE?GMA添加量为10 %、TPW604添加量为1 %时，复合材料的相容性和流动性均显著提升，复合材料的力学性能达到最优。     

Enhanced thermal conductivity and wear resistance of polytetrafluoroethylene composites through boron nitride and zinc oxide hybrid fillers

In this study, the thermal conductivity and wear resistance of the polytetrafluoroethylene (PTFE)/boron nitride (BN), PTFE/zinc oxide (ZnO), PTFE/tetra‐needle‐shaped zinc oxide whiskers (T‐ZnO), and PTFE/hybrid filler composites were investigated. Moreover, hot‐press molding was used to prepare the composites, and scanning electron microscopy was used to observe the morphology of the fillers and the friction interface of the composites. The results show that continuous thermally conductive paths could be formed in the PTFE/hybrid fillers (T‐ZnO and BN) composites so that the thermal conductivity of the PTFE was improved through addition of the hybrid fillers. Meanwhile, the synergistic effects of the hybrid fillers were useful for reducing the wear rate of the composites. In addition, for the pure PTFE, abrasive and adhesive wear was found. Compared to the worn surface of the pure PTFE, the worn surface of the PTFE composites filled with ZnO, T‐ZnO, BN, and hybrid fillers presented much smoother surfaces, and slighter ploughing occurred. Therefore, the hybrid fillers improved not only the thermal conductivity but also the wear resistance of the PTFE composites. The data obtained in this study contributed to the construction of a technical foundation for the preparation of composites with a high thermal conductivity and wear resistance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42302.     

Preparation and properties of dough‐modeling compound/fly ash/reclaim powder composites

A novel composite was prepared with reclaim powder (RP) matrix, dough‐modeling compound (DMC) reinforcement and fly ash (FA) filler in this article. The compatibility and crosslinking construction of the FA/RP composites were respectively, studied by the polarizing microscope and IR, the optimal formulation and experimental process were determined by measuring the mechanical properties such as shore A hardness, tensile strength, elongation at break, wear resistance and the thermal stability. The results showed that DMC/FA/RP composites exhibited extremely high mechanical and thermal properties when the mass ratio of the DMC/FA/RP composites was 45/25/100, and the cure condition is at 145°C for 30 min under 9 MPa. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Effect of polyethylene glycol on mechanical properties of bamboo fiber-reinforced polylactic acid composites

The bamboo fiber (BF)-reinforced polylactic acid (PLA) composites were prepared using the twin-screw extruder and injection molding. Thermal gravimetric analyzer results indicated the thermal stability of BF/PLA composites decreased with increasing BF content. Differential scanning calorimeter and X-ray diffraction curves showed that BF played a role as a nucleating agent, but the crystallinity of composite materials decreased with the increasing BF content. The melt flow rate of composites reduced with the increase in BF content, resulting in a poorer processing property. The processability of the composites was improved with the addition of high molecular polyethylene glycol (PEG). Mechanics performance test showed that tensile strength and bending strength of composites increased at low loading with the BF content increased then decreased when the loading continued to increase. The tensile strength of the composite materials reached 65.46 MPa when alkali-treated BF (ABF) content was 20 wt %. The flexural strength of the composites reached 97.94 MPa when ABF content was 10 wt %. Impact performance has also been improved. PEG-20000 was the best plasticizer among the PEG-6000,PEG-10000, and PEG-20000. When the component of PEG was 10 wt %, the elongation increased by 56%. The scanning electron microscopy (SEM) result showed that the fracture of the composites was smooth, most ABF were wrapped in matrix and distribution of ABF in PLA matrix was more uniform. It means that interfacial compatibility of bamboo fiber and PLA improved after BF modified by alkali. High molecular weight PEG enhance melt flow ability of polymer, result in fibers were further enclosed in the PLA matrix and increase properties of composites. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47709.     

The Processing and Characterization of Polyester/Natural Fiber Composites

The mechanical, thermal, and morphological properties of polycaprolactone (PCL) and bamboo fiber (BF) composites were evaluated. Composites containing maleic anhydride-grafted PCL (PCL-g-MA/BF) exhibited noticeably improved mechanical properties due to better compatibility between the two components in comparison to PCL/BF. The dispersion of BF in the PCL-g-MA matrix was clearly more homogeneous due to the creation of branched and cross-linked macromolecules via reactions between anhydride carboxyl groups in PCL-g-MA and hydroxyl groups in BF. The tensile strength and elongation of the PCL-g-MA/BF composites at break was considerably greater than that of PCL/BF composites. In a soil environment, PCL/BF biodegraded slightly faster than PCL-g-MA/BF. Finally, the PCL-g-MA/BF composites not only provided a plateau tensile strength at break up to 40 wt% BF but also provided more easily processing properties.     

Effects of fibre content and orientation on wear properties of basalt fibre/acrylonitrile–butadiene rubber composites

Basalt fibre (BF)/acrylonitrile–butadiene rubber (NBR) composites with various BF contents and orientations were prepared, and the curing, physical and mechanical properties and wear performance under block-on-ring abrasion conditions were evaluated. The results showed that the curing time was not obviously affected by the BFs. The addition of BFs increased the hardness but had negative influence on the tensile/tear strength of the NBR composites, especially when the BFs were oriented perpendicular to the tensile/tear direction with a high content, which should be due to the weak connection between the BFs and the rubber matrix. The coefficient of friction (COF) of the composites decreased significantly when BFs were added, whereas the content (3–30 phr) and the orientation of the fibres did not mainly affect the COF. Both parallel- and perpendicular-oriented BFs were effective at improving the wear resistance of the composites, and the former showed a better effect. With the BF content increase, the wear rate initially decreased and then remained basically stable. The COF and wear rate of the composites decreased by 27% and 35% when 12 phr BFs were added in a parallel direction. The excessive BFs, especially the perpendicularly-oriented BFs, led to fracture of the worn surface due to the abrasive grain wear caused by the crushed fibres.     

改性碳纳米管增强热塑性聚氨酯复合材料的性能研究

以碳纳米管（CNTs）和热塑性聚氨酯（TPU）为原料,通过硫酸（H₂SO₄）/硝酸（HNO₃）混合溶液处理碳纳米管颗粒表面以达到改性的效果,使用改性过后的碳纳米管熔融共混制备出TPU/CNTs复合材料。研究了不同含量的CNTs对TPU基体的流变、力学、耐磨性以及热性能的影响。结果表明, 改性过后的CNTs在TPU基体中形成了良好的分散性和相容性;TPU/CNTs复合材料在高频剪切下保留了复合材料的加工流动性,并且复合材料的拉伸强度以及耐磨性相较于TPU有明显的增强,其中在改性碳纳米管含量较低时,复合材料的力学性能改善较为明显;改性CNTs的加入提高了TPU基体的熔融温度和结晶度;改性CNTs的加入提高了复合材料的热降解温度,提高了TPU基体的热稳定性。     

Tribological mechanism improving the wear resistance of polyurethane/epoxy interpenetrating polymer network via nanodiamond hybridization

The excellent synergistic effect of physical/mechanical properties of polyurethane/epoxy (PU/EP) interpenetrating polymer network (IPN) and the validity of nanofilling have one potential to improve the wear resistance of polymeric materials. With the aim of practical application, PU/EP IPN nanocomposites are prepared with nanodiamond (ND) as a reinforcing additive. Results showed the uniform thermal stability and the excellent compatibility between PU and EP in ND‐hybridized PU/EP IPN. Simultaneously, ND particles work as crosslinked points improving the physical/mechanical properties of ND‐hybridized PU/EP IPN, especially the wear resistance. The measurement of tribological property and the scanning electron microscope indicated that the wear resistance is able to be improved a lot by the formation of IPN and by the addition of ND. Consequently, the tribological mechanism of PU/EP IPN nanocomposites comes into being. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40244.     

Microstructure and properties of Cu-Ti alloy infiltrated chopped Cf reinforced ceramics composites

Novel friction composites (C/C-Cu₅Si-TiC) were prepared via reactive melt infiltration (RMI) of Cu-Ti alloy into porous C/C-SiC composites. The microstructure, physical properties and tribological behaviors of the novel material were studied. Results were compared to conventional C/C-SiC composites produced by liquid silicon infiltration(LSI). The resultant composite showed the microstructure composed of Cu₅Si matrix reinforced with TiC particles and intact C/C structures. Most importantly, the composite did not present traces of free Si. As a result, the C/C-Cu₅Si-TiC composite showed higher flexural strength, impact toughness and thermal diffusivity in comparison to C/C-SiC composites. Tribological properties were measured using 30CrSiMoVA as a counterpart. In general, the C/C-Cu₅Si-TiC composites showed lower coefficient of friction(COF), but higher wear resistance and frictional stability. The improved wear resistance of the C/C-Cu₅Si-TiC composites is credited to the formation of friction films from Cu₅Si matrix. Other deformation and wear mechanisms are also described considering the microstructural observations.     

竹纤维含量对其增强聚己内酯复合材料性能的影响

将竹纤维（BF）与聚己内酯（PCL）熔融共混,通过模压工艺制备了竹纤维增强聚己内酯（PCL/BF）复合材料。研究和分析了BF含量对复合材料力学性能、热稳定性以及熔融、结晶行为的影响。结果表明,随着BF含量的增加,复合材料的拉伸性能、冲击性能和断裂伸长率均先升高后降低,当BF含量为40 %（质量分数,下同）时,分别达到最大值13.6 MPa、14.64 kJ/m^2和7.03 %;复合材料的热稳定性与BF和PCL的配比息息相关,受热过程中对彼此热解会产生抑制作用;BF的加入在一定程度上降低了PCL的熔融温度和结晶度,但结晶温度提高;BF含量超过40 %时,BF含量对复合材料吸水率的影响显著,且随着BF含量的增加,复合材料的吸水率快速增长。     

Preparation and performances of ethylene–propylene–diene terpolymer/acrylic rubber reinforced with a dough‐modeling compound

A novel composite was prepared by the addition of a dough‐modeling compound (DMC) reinforcement and an ethylene–propylene–diene terpolymer (EPDM)/acrylic rubber (ACM) matrix. We studied the DMC/EPDM/ACM mass ratio and vulcanizing process by testing the tensile strength, Shore A hardness, elongation at break, and wear and thermal properties. The results show that the mechanical properties, thermal properties, and wear resistance of the composites were good when the DMC/EPDM/ACM mass ratio was 70/25/75 and the cure conditions were 180°C under 10 MPa for 25 min. The crosslinking structure of the composites was studied by IR, and this further proved the interaction between DMC, ACM, and EPDM. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Highly enhanced tire performance achieved by using combined carbon nanotubes and soybean oil

In this study, the previously noted limitations of high-performance passenger tire tread were overcome by adding rough-surface carbon nanotubes and soybean oil to a high-loading silica-based elastomer composite. The results of the practical tire test demonstrated improved wet braking, dry braking, snow traction, and rolling resistance in comparison with the unmodified silica-based composite. Moreover, the wear resistance was enhanced by greater than 20% while commercially acceptable levels of the other properties were maintained, thereby minimizing the trade-off. The wet traction and dry stability of the tires were enhanced by the inclusion of carbon nanotubes, while the improved snow traction and wear resistance were increased by the soybean oil. Therefore, this carbon nanotube/soybean oil-based composite may represent a useful and practical means of improving high-loading silica-based elastomer composites.     

Friction and wear properties of basalt fiber reinforced/solid lubricants filled polyimide composites under different sliding conditions

Short basalt fibers (BFs)‐reinforced polyimide (PI) composites filled with MoS₂ and graphite were fabricated by means of hot‐press molding technique. The tribological properties of the resulting composites sliding against GCr15 steel ring were investigated on a model ring‐on‐block test rig. The wear mechanisms were also comparatively discussed, based on scanning electron microscopic examination of the worn surface of the PI composites and the transfer film formed on the counterpart. Experimental results revealed that MoS₂ and graphite as fillers significantly improved the wear resistance of the BFs‐reinforced polyimide (BFs/PI) composites. For the best combination of friction coefficient and wear rate, the optimal volume content of MoS₂ and graphite in the composites appears to be 40 and 35%, respectively. It was also found that the tribological properties of the filled BFs/PI composites were closely related with the sliding conditions such as sliding speed and applied load. Research results show that the BF/PI composites exhibited better tribological properties under higher PV product. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

油酸改性石墨烯/二硫化钼复合材料润滑添加剂的制备及摩擦学特性

为研究石墨烯基二硫化钼复合材料润滑添加剂对10^#白油（10^# White Oil,10^# WO）的摩擦磨损性能影响。采用水热反应法,以油酸为改性剂,以硫化钠为硫源,制备出油酸改性还原氧化石墨烯/二硫化钼（OA-RGO-MoS₂,ORM）及还原氧化石墨烯/二硫化钼（RGO-MoS₂,RM）复合材料,利用四球长时摩擦磨损试验机考察ORM和RM对10^# WO润滑性能的影响,借助多种现代表征手段分别对两种复合材料和磨痕进行表征分析。研究结果表明：ORM较RM具有更大的层间距、更高的石墨化程度、更好的热稳定性以及更加优异的分散稳定性。两种复合材料均在质量分数为0.2%时体现出最优异的润滑性能,其中,ORM由于经过油酸改性,产生的空间位阻效应使其润滑性能更加突出,最优条件下平均摩擦系数下降了42.2%。摩擦机理分析表明：RM与ORM均可在摩擦过程中通过吸附作用或摩擦化学反应在摩擦表面形成含有铁、氧、钼、碳和硫元素的润滑保护膜,从而起到减摩抗磨的作用。