加固用连续纤维增强热塑性树脂基复合材料预制片材的研究综述

本文综述了加固用连续纤维增强热塑性树脂基复合材料(CFRTP)预制片材的特点、原材料的发展情况、国内外现有的制备技术，指出该预制片材因为其具有优良的力学性能、良好的耐腐蚀性、低成本、成型周期短以及可回收等特点，将成为新型的加固材料而用于土木工程的加固修补领域。     

玻璃纤维毡增强热塑性复合片材的研制和应用

本文简要介绍了玻璃纤维毡增强聚丙烯片材的研制，性能和应用。     

长纤维增强热塑性塑料加工和应用的最新进展

本文对长纤维增强热塑性塑料的性能特点,注塑成型用设备、影响纤维损伤的注塑工艺参数、浇口和喷嘴结构、主要应用领域及发展前景等进行了综述。     

国外纤维增强热塑性塑料发展概况

纤维增强热塑性塑料（FRTP）因其重量轻,抗冲击性和疲劳韧性好,成型周期短,可循环利用等诸多优点,近年在稳定发展。本文概述了国外纤维增强热塑性塑料的发展形势、材料种类、知名厂商及其产品和FRTP最终制品的成型工艺。     

长纤维增强热塑性复合材料的开发与应用

长纤维增强热塑性复合材料以其优异的性能成为高分子复合材料研发与应用的热点。笔者综述了长纤维增强热塑性复合材料的性能特征、研发历史与现状、产品形式与制造技术、应用状况,展望了长纤维增强热塑性复合材料的发展前景。     

长纤维增强热塑性塑料

长纤维增强热塑性塑料 (LFRT)成为热塑性塑料市场增长最快的品种 ,因其重量轻、价廉、易于回收重复利用 ,在汽车工业中获得较多应用。大部分长纤维增强热塑性塑料 (LFRT)使用玻璃纤维 ,特殊应用时也可将碳纤维、钢纤维掺混入热塑性塑料中。大多数常用的树脂材料是聚丙烯 (PP)和尼龙 ,也有一些采用聚碳酸酯、ABS、聚酯、热塑性聚氨酯或聚苯硫醚。在喷模部件中 ,短纤维增强的热塑性塑料纤维长度约 0 .3mm ,而在LFRT部件中 ,纤维长达 3mm以上。LFRT应用最多的是汽车 ,2 0 0 1年全球LFRT市场约为 6万吨 ,年增长率 30 %。预计今后几年…     

轻质热塑性复合片材的制备技术与应用

轻质热塑性复合片材除了优异的比强度外，还具有A级表面、成型加工容易、制品设计自由度大等优点，近年来发展非常迅速。本文介绍了它的几种制备方法，重点关注国家专利技术——喷动流化法。由于其独特的性能特点，轻质热塑性片材必将在汽车、交通等领域获得更为广泛的应用。     

Environmental effects on glass fiber reinforced polypropylene thermoplastic composite laminate for structural applications

This article presents the mechanical and microstructural characterization of glass fiber reinforced polypropylene thermoplastic composite laminates (PP/Glass) exposed to tap water, salt solution, and freeze/thaw cycles. PP/Glass specimens were immersed at 23, 50, and 70°C in tap water to simulate the relative humidity of the direct environment and in a salt solution of 3% NaCl to simulate the effect of de‐icing salt. The measured flexural strengths of the specimens before and after exposure were considered as a measure of the durability performance of the specimens and were used for long‐term properties prediction based on the Arrhenius theory. In addition, the durability of PP/Glass to freeze/thaw cycles was studied for as received specimens and specimens saturated with tap water. Scanning electron microscopy was also used to characterize the effect of aging on the PP/Glass specimens. The results showed that the durability of PP/Glass composite is related to the quality of their consolidation. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers     

Short fiber reinforced thermoplastic polyurethane elastomer composites

Mechanical properties of thermoplastic polyurethane elastomer (TPE) reinforced with short fibers were studied. Two types of fibers were used as the discontinuous phase: an aromatic polyamide (Twaron, diameter: 12 μm) and carbon fiber (FCI 140/90-R33—diameter: 8–10 μm). Because of processing limitations, the maximum length of both fibers, after incorporation in the composites, was reduced to 3 mm. The TPE (continuous phase) was a polyol-polyester type [Elastollan—glass transition of short fiber segments: −42°C (1)]. Both types of composites had fiber concentration of 10, 20, and 30 phr. Component interaction is discussed, as well as the application of a third power polynomial to establish a relationship between the amount of fiber added and stress at break data. Stress-strength, tear resistance, shore A and B hardness, abrasion resistance, and compression set tests were performed. Composites reinforced with aromatic polyamides showed higher values in most of the tests, except in the abrasion resistance test, in which a smaller material loss was observed.     

Mechanical properties of short fiber reinforced thermoplastic blends

An immiscible thermoplastic component was added to a conventional short fiber reinforced polymer to study its effect on the mechanical properties of the composite. Because of the preferential wetting of the fiber reinforcement a continuous network was formed of fibers ‘welded’ together by the minor component within the matrix polymer.Polyethylene (PE) was used as the matrix, polyamide-6 (PA6) as dispersed polymer phase and glass fibers (GF) as reinforcement. The obtained composite retained unusually high values of the elasticity modulus at temperatures above the melting point of the matrix. The upper limit of the ‘applicability’ of the material is determined by the melting point of the minor component. A simple model was derived to describe the mechanical properties of the composite. The model shows a good agreement with the experimental data. The influence of the model parameters on the predictions of the model was examined.     

Preparation and characterization of graphene reinforced PA6 fiber

Here, we report the successful preparation of PA6/GO composite fibers through in situ polymerization and the melting spinning method. The results suggest that graphene has induced only minor changes on the relative viscosity yet exhibits significant effects on the crystallization characteristics. The SEM images of the fibers have shown several expended borders as a consequence of graphene addition. The maximum strength of the composite fibers (5.3 cN/dtex) has been reached 0.05 wt % graphene added to the system; the draw ratio was equaled to 3.8. Compared to the neat PA6 fiber, the fibers with graphene displayed superior creep resistance features; the creep rate constant was 0.38 at a 0.05 graphene concentration, with a draw ratio of 3.5. The approach employed in this research paves the way towards PA6/graphene nanocomposites have been prepared through in situ polymerization using caprolactam and graphene oxide/water pulp as starting materials. In situ polymerization approach facilitated a superior interaction between PA6 and graphene. Compared to graphene oxide powder, the graphene oxide in water pulp has prevented the agglomeration when added to the caprolactam melt, leading to its enhanced dispersion within the system. PA6/graphene as‐spun fiber has been produced by the mean of melt‐spinning strategy using a melt‐spinning machine, obtaining products with different draw ratios after drawing at 120 °C. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45834.     

Microhardness of carbon fiber reinforced epoxy and thermoplastic polyimide composites

We have examined the micro indentation hardness of a series of carbon fiber reinforced epoxy and thermoplastic polyimide (TPI) composites. In the epoxy systems, the influence of Nylon particles was studied. The effect of crystallization of the thermoplastic polyimide upon the microhardness values of the resin was also investigated. The microstructure of the TPI-composites was characterized by X-ray diffraction. The results show that the addition of carbon fibers to the neat resins greatly increases the microhardness and thus the yield stress of the composite. The value of the microhardness technique is highlighted in emphasizing the heterogeneity of the CFRC.     

对位芳纶树脂粉末及短切纤维增强热塑性树脂研究进展

综述了对位芳纶的树脂粉末、短切纤维和浆粕增强热塑性树脂的研究进展,包括与热塑性树脂的共混方法以及对增强热塑性复合材料的摩擦磨损和力学性能的影响。综述结果表明,对位芳纶树脂粉末增强热塑性树脂后具有优异的耐磨性能,但要求对位芳纶树脂粉末颗粒粒径在150 um以下,这种超细粉末对研磨加工要求较高;对位芳纶短切纤维的长度为1.5mm,并须对其表面进行改性处理,生产这种超短切纤维的短切机需进口且昂贵;对位芳纶浆粕可采取熔融共混后造粒和切断再熔融共混的方法避免团聚的产生。同时指出,国内对位芳纶企业在努力实现稳定规模化生产基础上,应积极进行下游产品的开发。     

Manufacturing and testing of long basalt fiber reinforced thermoplastic matrix composites

In this work, long basalt fiber reinforced composites were investigated and compared with short basalt fiber reinforced compounds. The results show that long fiber reinforced thermoplastic composites are particularly advantageous in the respects of dynamic mechanical properties and injection molding shrinkage. The fiber orientation in long basalt fiber reinforced products fundamentally differs from short basalt fiber reinforced ones. This results in more isotropic molding shrinkage in case of long basalt fiber reinforced composites. The main advantage of the used long fiber thermoplastic technology is that the special long fiber reinforced pellet can be processed by most conventional injection molding machines. During extrusion compounding the fibers in the compound containing 30 wt% fibers are fragmented to an average length of 0.48 mm (typical of short fiber reinforced thermoplastic compounds), this length decreases further during injection molding to 0.20 mm. Contrarily using long fiber reinforced pellets and cautious injection molding parameters, an average fiber length of 1.8 mm can be achieved with a conventional injection molding machine, which increased the average length/diameter ratio from 14 to 130. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

Impact behavior of a short glass fiber reinforced thermoplastic polyurethane

The temperature dependence of critical strain energy release rate (G_c′) and standardized Charpy notched impact strength (CNIS) were measured for a thermoplastic polyurethane (TPUR) reinforced with 30 wt% of short glass fibers (SGF) over a temperature interval ranging from −150°C 23°C (RT) at two strain rates, 70 and 150 s⁻¹, respectively. Fractographic observation of fracture planes was used to qualitatively assess the fracture modes and mechanisms. Adhesion between the reinforcement and the matrix was excellent and the integrity of the fiber‐matrix interfacial contact was relatively insensitive to exposure to hydrolysis during the immersion in boiling water for 100 hours. At temperatures above −30°C, there was a large extent of plastic deformation in the vicinity of crack planes while at temperatures below −50°C, the extent of plastic deformation was substantially reduced. This resulted in a change in the major energy dissipation mechanism and led to a decrease of both CNIS and G_c′ values for SGF/TPUR composites. It was suggested that the plastic deformation of TPUR matrix in the immediate vicinity of glass fibers was the primary source of energy dissipation at temperatures above −30°C, while the friction and fiber pull‐out was the main dissipative process below −50°C. Over the whole temperature interval investigated, greater G_c′ values were obtained at higher strain rate of 150 s⁻¹, without any significant change in the fractographic patterns observed on the fracture planes. The CNIS/G_c′ ratio, used to assess suitability of CNIS for comparison of materials, changed with temperature substantially suggesting that the functional dependences of CNIS and G_c′ on temperature differ substantially. Hence, CNIS data do not provide a reliable base for material selection and for design purposes in this case.     

Issues in diaphragm forming of continuous fiber reinforced thermoplastic composites

A literature survey is presented on sheet-forming methods and mechanisms for continuous fiber reinforced thermoplastics. The diaphragm forming process is shown to be one of the more promising fabrication routes for complex-curvature structures. The primary deformation mechanisms involved in the sheet-forming processes are identified and discussed. Earlier approaches to develop mathematical models either have been kinematically based or have treated only one of the primary deformation mechanisms. A promising constitutive model for the highly anisotropic behavior of the composite at forming temperature is examined. The composite sheet is assumed to behave as a transversely isotropic Newtonian fluid that is both incompressible and inextensible in the fiber direction. The second section of the paper treats the experimental development of the polymeric diaphragm forming process for thermoplastic composites. The viscoelastic properties of the diaphragm material are characterized by dynamic mechanical analysis. The rate sensitivity of the phenomenon of shear-buckling during forming of certain cross-ply and quasi-isotropic composite laminates is investigated, using a shallow female mold. Finally, the interface condition between the diaphragm and the composite during forming is examined.