Pultruded fiber reinforced thermoplastic poly(methyl methacrylate) composites. Part II: Mechanical and thermal properties

A novel process has been developed to manufacture poly(methyl methacrylate) (PMMA) pultruded parts. The mechanical and dynamic mechanical properties, environmental effects, postformability of pultruded composites and properties of various fiber (glass, carbon and Kevlar 49 aramid fiber) reinforced PMMA composites have been studied. Results show that the mechanical and thermal properties (i.e. tensile strength, flexural strength and modulus, impact strength and HDT) increase with fiber content. Kevlar fiber/PMMA composites possess the highest impact strength and HDT, while carbon fiber/PMMA composites show the highest tensile strength, tensile and flexural modulus, and glass fiber/PMMA composites show the highest flexural strength. Experimental tensile strengths of all composites except carbon fiber/PMMA composites follow the rule of mixtures. The deviation of carbon fiber/PMMA composite is due to the fiber breakage during processing. Pultruded glass fiber reinforced PMMA composites exhibit good weather resistance. They can be postformed by thermoforming, and mechanical properties can be improved by postforming. The dynamic shear storage modulus (G′) of pultruded glass fiber reinforced PMMA composites increased with decreasing pulling rate, and G′ was higher than that of pultruded Nylon 6 and polyester composites.     

Pultruded fiber-reinforced poly(methyl methacrylate) composites. II. Static and dynamic mechanical properties,environmental effect,and postformability

This paper presents a novel process developed to manufacture poly(methyl methacrylate) (PMMA) pultruded composite. The mechanical, thermal, and dynamic mechanical properties, environmental effect, postformability of various fiber (glass, carbon, and Kevlar 49 aramid fiber) reinforced pultruded PMMA composites have been studied. Results show mechanical properties (i.e., tensile strength, specific tensile strength, tensile modulus, and specific flexural strength) and thermal properties (HDT) increase with fiber content. Kevlar fiber/PMMA composites possess the highest specific tensile strength and HDT, carbon fiber/PMMA composites show the highest tensile strength and tensile modulus, and glass fiber/PMMA composites show the highest specific flexural strength. Pultruded glass-fiber-reinforced PMMA composites exhibit good weather resistance. These composite materials can be postformed by thermoforming under pressure, and mechanical properties of postformed products can be improved. The dynamic shear storage and loss modulus (G′, G″) of pultruded glass-fiber-reinforced PMMA composites increased with decreasing pulling rate, and their shear storage moduli are higher than those of pultruded Nylon 6 and polyester composites.     

The unidirectional glass fiber reinforced furfuryl alcohol for pultrusion. II. Correlation of processing parameters for optimizing the process

Unidirectional glass fiber reinforced furfuryl alcohol (FA) composites have been prepared by the pultrusion processes. The optimum processing parameters of the glass fiber reinforced FA composites by pultrusion has been studied. The effects of the optimum processing parameters on the properties (flexural strength, flexural modulus, notched Izod impact strength, glass transition temperature (T_g), dynamic shear storage modulus (E'), shrinkage ratio, and roughness) investigated including die temperature, pulling rate, postcure temperature and time, and filler type and content. Results show that the pultruded composites possessed various optimum pulling rates at different die temperatures. On the basis of the DSC diagram, the swelling ratio and the mechanical properties of pultruded composites, the optimum die temperature can be determined. The mechanical properties and T_g increase at a suitable postcure temperature and time. Furthermore, the properties which decrease due to the degradation of pultruded composites for a long postcure time will be discussed. The mechanical properties of pultruded composites reach a maximum value at various filler content corresponding to the talc and calcium carbonate, respectively, and then decreased. When the fillers are added to the pultruded glass fiber reinforced FA composites, the shrinkage ratio of composites become smaller, and the surface of composites became smooth. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

聚丙烯/马来酸酐接枝聚丙烯/环氧树脂/玻璃纤维复合材料的制备及其性能研究

通过双螺杆挤出机制备了聚丙烯/马来酸酐接枝聚丙烯/环氧树脂/玻璃纤维（PP/PP-g-MAH/EP/GF）复合材料,并研究了PP-g-MAH含量、EP含量及固化剂对复合材料力学性能的影响。结果表明,PP-g-MAH含量为10份,含有固化剂EP的含量为3份时,复合材料的综合力学性能最佳;与不加EP的复合材料相比,其拉伸强度、弯曲强度、冲击强度分别提高了41 %、47 %、86 %。扫描电子显微镜分析表明,EP的加入明显改善了GF和PP基体的黏结强度。     

纳米二氧化硅对PBT力学和结晶性能的影响

采用熔融共混的方法,将纳米SiO2添加到聚对苯二甲酸丁二醇酯(PBT)中,制备出PBT/纳米SiO2复合材料,对其力学和结晶性能进行分析研究。结果表明,随着纳米SiO2含量增加,PBT/纳米SiO2复合材料的拉伸强度和弯曲强度增加,PBT的结晶度增加,球晶尺寸减小,最大扭矩和平衡扭矩变化不大。当纳米SiO2含量为0.1份时,PBT的拉伸强度提高12%,断裂伸长率提高100%,冲击强度提高10%,弯曲强度提高5%,综合力学性能最好。     

Simultaneous full‐interpenetrating polymer networks of blocked polyurethane and vinyl ester. II. Static and dynamic mechanical properties

Simultaneous full‐interpenetrating polymer networks (full‐IPNs) based on blocked polyurethane (PU) and vinyl ester (VE) have been prepared. The static and dynamic properties of these IPNs have been examined. Results show that the tensile strength and flexural strength of IPNs increased with blocked PU content to a maximum value at 7.5 wt % PU content and then decreased. The tensile modulus, flexural modulus, and hardness of IPNs decreased with increasing blocked PU content. The impact strength of IPNs increased with increasing blocked PU content. The tensile strength, flexural strength, tensile modulus, and flexural modulus of IPNs increased with filler (kaolin) content to a maximum value at 20 to 25 phr filler content and then decreased. The higher the filler content, the greater the hardness, and the lower the impact strength of IPNs. The tensile strength, flexural strength, tensile modulus, flexural modulus, and hardness of IPNs increased with increasing VE initiator content. The dynamic technique was used to determined the damping behavior across a temperature range. Results show that the glass transition temperature (T_g) of IPNs are shifted inwardly compared with pure PU and VE, which indicated that the blocked PU–VE IPNs showed excellent compatible. Meanwhile, the glass transition temperature was shifted to a higher temperature with increased filler content. The dynamic storage modulus (E′) of IPNs increased with increasing VE and filler content. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1977–1985, 1999     

Mechanical and Damping Properties of Glass Fiber and Mica-Reinforced Epoxy Composites

Mica/glass fiber-reinforced epoxy with 0° and 45° ply angle were prepared by hand lay-up and the mechanical and damping properties were studied. Results show that the addition of mica resulted in decrease of tensile strength and modulus for both composites. Althogh flexural strength and modulus of composites with 45° appeared a maximum at 5 phr mica loading, that of composites with 0° reached a maximum at 10 phr mica loading. For composites with 0°, damping ratio reaches maximum at 5 phr mica. Although for composites with 45°, damping ratio decrease with increasing mica loading.     

锦葵纤维增强聚丙烯基复合材料力学性能研究

分别制备了锦葵纤维含量为10 %（质量分数,下同）、20 %、30 %、40 %和50 %的锦葵纤维增强增强聚丙烯基复合材料,研究了纤维含量对该复合材料拉伸性能和弯曲性能的影响,并与苎麻纤维增强聚丙烯基复合材料进行了对比。结果表明,随着锦葵纤维含量的增加,锦葵纤维增强聚丙烯基复合材料的拉伸强度和拉伸弹性模量逐渐增加,而弯曲强度和弯曲弹性模量呈现先增大后减小的趋势,当纤维含量为40 %时达最大值;纤维含量均为30 %时,除拉伸弹性模量外,锦葵纤维增强聚丙烯基复合材料的各项指标均低于苎麻纤维增强聚丙烯基复合材料。     

Mechanical and Thermal Performances of Roselle Fiber-Reinforced Thermoplastic Polyurethane Composites

The aim of this paper is to present research findings on the measurements of mechanical, morphological, and thermal properties of Roselle fiber-reinforced thermoplastic polyurethane composites. The Roselle fiber/thermoplastic polyurethane composites were prepared with fibers of different sizes such as 125?µm and lower, 125–300 and 300–425?µm by internal mixer and hot press at 170°C. The results show that mechanical properties (tensile, flexural, and impact properties) of the composites were improved with the increase in fiber sizes. The highest tensile (10.45?MPa), flexural strength (6.93?MPa), and impact strength (20.22 kJ/m²) was obtained from composites with 300–425?µm fiber size of Roselle fiber/thermoplastic polyurethane composites. Morphological properties of dispersion fiber and tensile fracture surfaces were studied using scanning electron microscope. Thermal properties of the composites were studied using thermogravimetric analyses and results showed that the thermal decomposition effect was almost similar for all compositions.     

Mechanical properties of blocked polyurethane/epoxy interpenetrating polymer networks

The mechanical properties of blocked polyurethane(PU)/epoxy interpenetrating polymer networks (IPNs) were studied by means of their static and damping properties. The studies of static mechanical properties of IPNs are based on tensile properties, flexural properties, hardness, and impact method. Results show that the tensile strength, flexural strength, tensile modulus, flexural modulus, and hardness of IPNs decreased with increase in blocked PU content. The impact strength of IPNs increased with increase in blocked PU content. It shows that the tensile strength, flexural strength, tensile modulus, and flexural modulus of IPNs increased with filler (CaCO₃) content to a maximum value at 5, 10, 20, and 25 phr, respectively, and then decreased. The higher the filler content, the greater the hardness of IPNs and the lower the notched Izod impact strength of IPNs. The glass transition temperatures (T_g) of IPNs were shifted inwardly compared with those of blocked PU and epoxy, which indicated that the blocked PU/epoxy IPNs showed excellent compatibility. Meanwhile, the T_g was shifted to a higher temperature with increasing filler (CaCO₃) content. The dynamic storage modulus (E′) of IPNs increased with increase in epoxy and filler content. The higher the blocked PU content, the greater the swelling ratio of IPNs and the lower the density of IPNs. The higher the filler (CaCO₃) content, the greater the density of IPNs, and the lower the swelling ratio of IPNs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1826–1832, 2006     

Interpenetrating polymer networks of polyurethane and furfuryl alcohol. I. Morphology and mechanical properties

Polyurethane/furfuryl alcohol (PU/FA) interpenetrating polymer networks (IPNs) were synthesized from furfuryl alcohol using p-toluene sulfonic acid as a catalyst and blocked NCO-terminated PU prepolymer with m-xylylenediamine (MXDA) as a chain extender. From IR spectrum analysis it was found that the major reactions in the PU/MXDA/FA system are the polymerization of PU/MXDA and the self-polymerization of FA. The tensile strengths of PU/FA IPNs that contain 5 p.h.r. PU are greater than those of the pure components. The flexural strength, flexural modulus, Shore D hardness and HDT decrease and the notched Izod impact strength increases with the polyurethane content. The compatibility of the compounds in these PU/FA IPNs was investigated by dynamic mechanical analysis and scanning electron microscopy. It was found that glass transition temperatures are shifted inwardly which indicated that the PU/FA IPNs were semicompatible. It was confirmed from scanning electron micrography that the system was heterogeneous.     

Pultruded fiber-reinforced polyurethane-toughened phenolic resin. II. Mechanical properties,thermal properties,and flame resistance

A novel process has been developed to toughen phenolic resin by polyurethane for fiber-reinforced pultruded composites. The mechanical properties of the composites (tensile strength, flexural strength, and notched Izod impact strength) approach maximum values at 10 wt% of the blocked polyurethane content. The fabricated composites show good mechanical properties and possess low void fraction. Notched Izod impact strength of the composite (with 5 wt% polyurethane content) increases by more than 30% compared to the virgin composite. The thermogravimetric analysis (TGA) showed that the temperature for the 5% weight loss of the phenolic/polyurethane copolymer decreases with the increasing of the polyurethane content; however, the thermal degradation temperature is still higher than 350°C. Differential scanning calorimetric analysis (DSC) showed that the onset point of copolymer is 20°C higher than that of the virgin one. The presence of the blocked polyurethane may hinder the polymerization of phenolic resin. The modified composite shows excellent dimensional stability. The copolymer composite also possesses good fire resistance. © 1996 John Wiley & Sons, Inc.     

废旧聚丙烯/废弃印刷线路板非金属粉复合材料的制备及性能

采用挤出注塑法以废旧聚丙烯（WPP）为基体、废弃线路板非金属粉（WPCBN）为填料制备了复合材料。考察了WPCBN对材料阻燃性能及力学性能的影响。通过红外光谱和扫描电子显微镜分析研究了WPCBN改性前后官能团结构及复合材料冲击断面形貌的差异,以探讨硅烷偶联剂（KH550）、马来酸酐接枝聚丙烯（MAPP）对WPP/WPCBN界面相容性改善及复合材料力学性能提高的作用机理。结果表明,WPCBN超过10 phr后复合材料具有自熄性;经1.5 phr KH550改性后,WPCBN与WPP间的界面黏结力增强,复合材料拉伸、弯曲及冲击强度分别提高6.5%、6.25%和17.9%;m（WPP）：m（WPCBN）：m（MAPP）为100：30：9时,复合材料的拉伸、弯曲强度增幅最大,分别为37.5%和48.8%;WPP/WPCBN与新聚丙烯（NPP）/WPCBN复合材料相比,拉伸、弯曲强度仅降低16.8%、20.4%。     

Mechanical properties,thermal stability,and flame retardance of pultruded fiber-reinforced poly(ethylene oxide)-toughened novolak-type phenolic resin

The mechanical properties (flexural modulus, static tensile strength, notched Izod impact strength), miscibility, thermal stability, and flame retardance of a poly(ethylene oxide) (PEO)-toughened phenolic resin glass pultruded composite were investigated. The mechanical properties of a pultruded glass fiber-reinforced modified phenolic resin composite increased while the soft segment of PEO absorbs the loads in the network of brittle phenolic resin. The phenolic/PEO blend is completely miscible, from the results of differential scanning calorimetry. Its thermal degradation temperature is always higher than 370°C and decreased with increasing PEO content. The morphology of the interface between the fiber and matrix is well wetted-out with increasing PEO content from the result with a scanning electron microscope (SEM). The modified phenolic composite also shows excellent flame retardance that is UL-94, V-0, and the limited oxygen index is more than 55. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1129–1136, 1998     

The effect of multiscale hybridization on the mechanical properties of natural fiber-reinforced composites

The main objective of this work was to investigate the effect of reinforcements at different scales on the mechanical properties of natural fiber-reinforced composites. Pure jute and interlaminar hybrid jute/glass fiber-reinforced polymer composites were fabricated. Different types of fillers in two weight fractions (1 and 3 wt. %) were used as second reinforcements in the hybrid jute/glass composites. Tensile, flexural, and impact tests were performed. It was found that the macroscale inter-play hybridization significantly improved the mechanical properties of the pure jute fiber based composites. When the fillers are used as second hybridization, the modified composites presented higher mechanical properties when compared to pure jute composites. However, the effect of fillers on the mechanical properties of the hybrid composites presented various trends due to the interaction between several factors (i.e., particle scale, content, and nature), which cannot always be separated. Increasing the synthetic filler content improved the tensile properties of the filled hybrid composites, while increasing the natural filler content worsen the tensile properties. The flexural strength of the multiscale hybrid composites was improved, while the impact properties were negatively affected.     

Mechanical properties of talc‐ and (calcium carbonate)‐filled poly(vinyl chloride) hybrid composites

The main objective of this study was to investigate and compare the mechanical properties of poly(vinyl chloride) (PVC) composites filled with calcium carbonate (CaCO₃), talc, and talc/CaCO₃. Talc and CaCO₃ with different grades were incorporated into the PVC matrix. To produce the composites, the PVC resin, fillers, and other additives were first dry‐blended by using a laboratory mixer before being milled into sheets in a two‐roll mill. Test specimens were prepared by compression molding, after which the mechanical properties of the composites were determined. Single and hybrid filler loadings used were fixed at 30 phr (parts per hundred parts of resin). Talc‐filled composite showed the highest flexural modulus and the lowest impact strength, whereas uncoated, ground, 1‐μm CaCO₃ (SM 90) showed optimum properties in terms of impact strength and flexural modulus among all grades of CaCO₃. It was selected to combine with talc at different ratios in the hybrid composites. The impact strength of the hybrid composites gradually increased with increasing SM 90 content, but the flexural and tensile properties showed an opposite behavior. Hybrid (10 phr talc):(20 phr SM 90)‐filled PVC composite reached a synergistic hybridization with balanced properties in impact strength, as well as flexural and tensile properties. J. VINYL ADDIT. TECHNOL., 2012. © 2012 Society of Plastics Engineers     

废聚丙烯/废轮胎胶粉/废尼龙短纤维复合材料 Ⅰ.配方

用双螺杆挤出机制备了废聚丙烯/废轮胎胶粉/废尼龙短纤维(WPP/GRT/WSF)复合材料,通过正交实验得出了制备该复合材料的最佳配方,讨论了增容剂用量、氯化聚丙烯的含氯质量分数、GRT用量及其粒径、WSF用量及预处理对该复合材料力学性能的影响。结果表明,制备该复合材料的最佳配方(质量份,下同)是WPP100,GRT30,WSF8,二甲基二硫代氨基甲酸锌、二硫化二苯并噻唑、多乙烯多胺及重油用量依次为0.6,1.2,0.3,2,聚丙烯接枝马来酸酐、氯化聚丙烯用量依次为8,4;在最佳配方下,该复合材料的非缺口冲击强度为25.2kJ/m2,拉伸强度为13.6MPa;GRT用量为30份时,该复合材料的拉伸强度和非缺口冲击强度最大,GRT的最佳粒径为40目;WSF经D法预处理后,提高了该复合材料的力学性能,拉伸强度为16.3MPa,非缺口冲击强度为27.8kJ/m2。     

香蕉纤维的表面改性及其增强环氧树脂复合材料的性能研究

采用硅烷偶联剂(A-174)偶联、高锰酸钾接枝和乙酰化包覆等3种方法对香蕉纤维进行表面改性,制备了改性香蕉纤维增强环氧树脂复合材料,测试其拉伸、弯曲、压缩、冲击等力学性能。结果表明,偶联、接枝、包覆等表面改性均能明显改善香蕉纤维与基体树脂的相容性,提高复合材料的力学性能,其中偶联改性的效果最好。当改性香蕉纤维含量为10wt%时,与未改性的香蕉纤维比较,复合材料的拉伸强度、弯曲强度、压缩强度分别提高了1.8、1.0、2.6倍;随着纤维含量的增加,复合材料的力学性能明显提高。     

Mode I and Mode II delamination resistance and mechanical properties of woven glass/epoxy–PU IPN composites

The effect of polyurethane on the mechanical properties and Mode I and Mode II interlaminar fracture toughness of glass/epoxy composites were studied. Polyurethanes (PU) synthesized using polyols and toluene diisocyanate were employed as modifier for epoxy resin by forming interpenetrating polymer network. The PU/Epoxy IPN was used as matrix material for GFRP. PU modified epoxy composite laminates having varying PU contents were prepared. The effect of PU content on the mechanical properties like interlaminar fracture toughness (Mode I, G_1c and Mode II, G_IIc), tensile strength, flexural strength, and Izod impact strength were studied. The morphological studies were conducted on the fractured surface of the composite specimen by scanning electron microscopy (SEM). Tensile strength, flexural strength, and impact strength of PU‐modified epoxy composite laminates were found to increase inline with interlaminar fracture toughness (G_1c and G_IIc) with increasing PU content to a certain limit and then it was found to decrease with increase in PU content. It was observed that toughening of epoxy with PU increases the Mode I and Mode II delamination toughness up to 17 and 120% higher than that of untoughened composite specimen, respectively. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

聚氨酯/环氧树脂互穿网络聚合物硬质泡沫机械性能研究

采用同步法合成了聚氨酯/环氧树脂互穿网络聚合物(PU/EP IPN)硬质泡沫,对机械性能进行了研究。结果表明,与纯聚氨酯硬质泡沫相比,PU/EP IPN硬质泡沫的压缩强度和弯曲强度明显提高,在PU/EP IPN硬质泡沫中,随环氧树脂含量增加,PU/EP IPN硬质泡沫压缩强度和弯曲强度随之增大,当E-39D质量分数增加到24.2%时,PU/EP IPN硬质泡沫压缩强度和弯曲强度出现最大值;PU/EP IPN硬质泡沫机械强度随材料密度的增大而增加;随着环氧树脂中环氧值的增加,PU/EP IPN硬质泡沫的压缩强度、弯曲强度和拉伸强度均呈逐渐升高的趋势。