Binders for jute-reinforced unsaturated polyester resin

Reinforcement of polyester resin with jute cloth under constant load is studied, The pretreatment of jute cloth with tetrahydrofuran and the effect of binding properties of poly(vinyl acetate) and acrylic acid and their effect on the impact, tensile, and water absorptions of jute cloth polyester composites are reported and their chemical reactions are discussed.     

SPEEK复合膜在电解制备过硫酸铵中的应用

为达到减少电解制备过硫酸铵的能耗及提高电流效率的目的,从改良电解槽隔膜的角度出发,分别对几种自制复合膜的电解性能进行了考察和比较,并对它们的机械强度和支撑层的耐腐蚀性进行了测试。通过试验发现：聚酯滤布的耐电解液腐蚀性最好;以100目聚酯滤布为支撑层制得的磺化聚醚醚酮（SPEEK）复合膜机械强度最高;以50目聚酯滤布为支撑层制得的SPEEK复合膜的电流效率最高且单位电耗最低。综合考虑,以50目聚酯滤布为支撑层制得的SPEEK复合膜比较适合应用于电解制备过硫酸铵中,尽管它的机械强度不是最大,但是与不添加支撑层的纯SPEEK膜相比其机械强度有了明显的提高,而且具有较高的电流效率和比较小的能耗。     

Effect of the atmospheric plasma treatment parameters on jute fabric: The effect on mechanical properties of jute fabric/polyester composites

The effect of atmospheric air plasma treatment of jute fabrics on the mechanical properties of jute fabric reinforced polyester composites was investigated. The jute fabrics were subjected to different plasma powers (60, 90, and 120 W) for the exposure times of 1, 3, and 6 min. The effects of plasma powers and exposure times on interlaminar shear strength, tensile strength, and flexural strength of polyester based composites were evaluated. The greatest ILSS increase was about 171% at plasma power of 120 W and exposure time of 6 min. It is inferred that atmospheric air plasma treatment improves the interfacial adhesion between the jute fiber and polyester. This result was also confirmed by scanning electron microscopy observations of the fractured surfaces of the composites. The greatest tensile strength and flexural strength values were determined at 120 W for 1 min and at 60 W for 3 min, respectively. Moreover, it can be said that atmospheric air plasma treatment of jute fibers at longer exposure times (6 min) made a detrimental effect on tensile and flexural properties of jute‐reinforced polyester composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Thermomechanical properties of alkali treated jute‐polyester/nanoclay biocomposites fabricated by VARTM process

A systematic study was carried out to investigate the effect of alkali treatment and nanoclay on thermomechanical properties of jute fabric reinforced polyester composites (JPC) fabricated by the vacuum‐assisted resin transfer molding (VARTM) process. Using mechanical mixing and sonication process, 1% and 2% by weight montmorillonite K10 nanoclay were dispersed into B‐440 premium polyester resin to fabricate jute fabric reinforced polyester nanocomposites. The average fiber volume was determined to be around 40% and void fraction was reduced due to the surface treatment as well as nanoclay infusion in these biocomposites. Dynamic mechanical analysis (DMA) revealed enhancement of dynamic elastic/plastic responses and glass transition temperature (T_g) in treated jute polyester composites (TJPC) and nanoclay infused TJPC compared with those of untreated jute polyester composites (UTJPC). Alkali treatment and nanoclay infusion also resulted in enhancement of mechanical properties of JPC. The maximum flexural, compression, and interlaminar shear strength (ILSS) properties were found in the 1 wt % nanoclay infused TJPC. Fourier transform‐infrared spectroscopy (FT‐IR) revealed strong interaction between the organoclay and polyester that resulted in enhanced thermomechanical properties in the composites. Lower water absorption was also observed due to surface treatment and nanoclay infusion in the TJPC. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

不饱和聚酯片状模塑料力学性能的研究

研究了玻纤布、短切玻纤及碳酸钙对不饱和聚酯片状模塑料力学性能的影响,实验发现:玻纤布增强不饱和聚酯片状模塑料的力学性能比短切玻纤好,随着玻纤含量的增加,不饱和聚酯片状模塑料的拉伸强度先增加,达到一极大值之后减少。碳酸钙填充不饱和聚酯片状模塑料,随着碳酸钙含量的增加,不饱和聚酯片状模塑料的拉伸强度明显降低,弯曲强度增加。     

Study of jute fiber reinforced polyester composites by dynamic mechanical analysis

Cyanoethylation of jute fibers in the form of nonwoven fabric was studied, and these chemically modified fibers were used to make jute–polyester composites. The dynamic mechanical thermal properties of unsaturated polyester resin (cured) and composites of unmodified and chemically modified jute–polyester were studied by using a dynamic mechanical analyzer over a wide temperature range. The data suggest that the storage modulus and thermal transition temperature of the composites increased enormously due to cyanoethylation of fiber. An increase of the storage modulus of composites, prepared from chemically modified fiber, indicates its higher stiffness as compared to a composite prepared from unmodified fiber. It is also observed that incorporation of jute fiber (both unmodified and modified) with the unsaturated resin reduced the tan δ peak height remarkably. Composites prepared from cyanoethylated jute show better creep resistance at comparatively lower temperatures. On the contrary, a reversed phenomenon is observed at higher temperatures (120°C and above). Scanning electron micrographs of tensile fracture surfaces of unmodified and modified jute–polyester composites clearly demonstrate better fiber–matrix bonding in the case of the latter. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1505–1513, 1999     

Study on Mechanical and Dielectric Properties of Jute Fiber Reinforced Low-Density Polyethylene (LDPE) Composites

Abstract

Jute fiber (Hessian cloth) reinforced low-density polyethylene (LDPE) composites were prepared by heat press molding techniques. The mechanical properties such as tensile strength (TS), bending strength (BS), and elongation at break of the composites were studied. The enhancement of TS (33%) and BS (50%) were obtained as a result of reinforcment jute fabrics in LDPE. In order to improve the mechanical properties and adhesion between jute and LDPE, hessian cloth were each treated with 2-hydroxyl ethyl methacrylate (HEMA). The HEMA-treated jute composite showed higher tensile and bending strength compared to untreated jute composite and LDPE. Dielectric properties like dielectric constant and loss tangent (tan δ) of jute, LDPE and composites were studied. Ferro to paraelectric phase transition occurred in both treated and untreated jute composites containing more than 20% jute. Water uptake behaviors of the composite were monitored and HEMA-treated composite showed lower water absorption behavior. The adhesion nature of jute and LDPE also characterized by scanning electronic microscopy (SEM), better adhesion was observed between HEMA-treated jute and LDPE over untreated ones.     

黄麻纤维增强不饱和聚酯树脂初步研究

以油酸为偶联剂,将氢氧化钠-油酸处理后的黄麻纤维布作为填充材料制备了不饱和聚酯复合材料,并对氢氧化钠处理黄麻纤维的适宜浓度、复合材料的拉伸强度、冲击强度、吸水率进行了研究测试。结果表明:氢氧化钠的适宜浓度为20%,黄麻纤维增强不饱和聚酯树脂的冲击强度及拉伸强度最大值分别为12.75 kJ/m2和33.05 MPa,复合材料的最大吸水率为4.07%。经油酸处理的黄麻纤维可有效提高不饱和聚酯复合材料的性能。     

Effect of additives on reinforcement of radiation-induced jute-urethane polymer composites

Thick polymer film was prepared under gamma irradiation using urethane acrylate in the presence of N-vinylpyrrolidone, ethyl hexyl acrylate, and trimethylol propane triacrylate. Both jute dust and hessian cloth (jute fabric) were used to constitute composites based on the prepared resin matrix. Some of their physical and mechanical properties were studied. Some additives such as acetic acid, acrylamide, urea, talc, and titanium oxide were incorporated into the formulation to investigate their effect on the physical and mechanical properties. Water absorption and weathering resistance of the resin and composites were also investigated. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 79–85, 1998     

Effect of γ‐aminopropyl trimethoxy silane on the performance of jute–polycarbonate composites

The composites of jute fabrics (hessian cloth) and polycarbonate were prepared by compression molding. The jute surface was modified with γ‐aminopropyl trimethoxy silane (Z‐6011) to improve interfacial adhesion between jute and polycarbonate. The treated and untreated jute surfaces as well as composites were investigated by X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Environmental scanning electron microscopy, Dynamic mechanical analysis, and mechanical testing. XPS and FTIR assure that the silane plays important role to form interfacial bonding with the jute fibers and polycarbonate. The surface topography of silanized and virgin fibers, and the interfacial adhesion properties of the composite were investigated by ESEM. DMA analysis shows the improved storage and loss moduli of silanized jute composite as compared to the untreated one. The modified jute composite also produces enhanced mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4142–4154, 2006     

Impregnation of thermoplastic resin in jute fiber mat

Impregnation rate of thermoplastic resin (polypropylene) in jute fiber mat and influence of relative factors on impregnation were studied, aiming to develop the continuous melt impregnation technique and to investigate the effect of impregnation rate and temperature on processing conditions and mechanical properties of natural fiber mat-reinforced thermoplastics. Influence of pressure on porosity of fiber mat and effect of melt viscosity on impregnation rate were also investigated. The modified capillary rheometer was used as apparatus and experimental data were analyzed based on the one-dimension Darcy’s law. Results showed that at a given pressure, the impregnation rate is inversely proportional to melt viscosity and jute fiber mat has higher porosity than glass fiber mat. The architecture, compressibility, permeability and fiber diameter of jute fiber mat were compared with those of glass fiber mat and their effects on impregnation were discussed further. It could be seen that the average diameter of jute fiber is much bigger; the porosity of jute fiber mat is significantly higher and inner bundle impregnation does not exist in jute fiber mat. Therefore, it is not difficult to understand why the impregnation rate in jute fiber mat is 3.5 times higher and permeability is 14 times greater. Kozeny constants of jute and glass fiber mats calculated based on the capillary model are 2950 and 442, respectively.     

十二烷基磷酸单酯抗静电性能研究

按照GB/T 16801-1997中的方法对十二烷基磷酸单酯的抗静电性能进行研究,考察了十二烷基磷酸单酯钾盐、钠盐、三乙醇胺盐以及未中和的磷酸单酯对聚酯布的抗静电性能,结果表明:钾盐和未中和的磷酸单酯对聚酯布的抗静电效果较好。在确定了使用钾盐和未中和的磷酸单酯作为抗静电剂的条件下,考察了它们的质量浓度对聚酯布抗静电性能的影响,结果表明:当单酯钾盐的质量浓度为4 g/L,单酯为6 g/L时,对聚酯布的抗静电性能较好。在单酯钾盐的质量浓度为4 g/L,单酯为6 g/L时,考察了它们对聚酯布、棉布和腈纶布的抗静电效果,结果表明:它们对腈纶布的抗静电效果都好于其他2种布。在考察了十二烷基磷酸单酯的抗静电性能后,对其抗静电机理进行了探讨。     

Fiber matrix interactions in jute reinforced polyester resin

The effect on packing resulting from the filling of unsaturated polyester resin with fillers and jute fibers has been investigated. The influence of absorbed water on the interfacial interactions involved in the fiber matrix system of the jute reinforced polyester resin also are discussed. An approach to reduce water absorption and soluble matter lost from the jute reinforced polyester resin is proposed.     

Experimental characterization of woven jute‐fabric‐reinforced isothalic polyester composites

In this article, mechanical performance of isothalic polyester‐based untreated woven jute‐fabric composites subjected to various types of loading has been experimentally investigated. The laminates were prepared by hand lay‐up technique in a mold. Specimens for tests were fabricated as per ASTM standards. All the tests (except impact) were conducted on closed loop servo hydraulic MTS 810 material test system using data acquisition software Test Works‐II. From the results obtained, it was found that the tensile strength and tensile modulus of jute‐fabric composite are 83.96% and 118.97% greater than the tensile strength and modulus of unreinforced resin, respectively. The results of other properties, such as flexural, in‐plane shear, interlaminar shear, impact, etc., also revealed that the isothalic‐polyester‐based jute‐fabric composite have good mechanical properties and can be a potential material for use in medium load‐bearing applications. The failure mechanism and fiber‐matrix adhesion were analyzed by scanning electron microscope. Effects of long‐term immersion in water on mechanical properties are also presented. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2650–2662, 2007     

Biodegradable jute cloth reinforced thermoplastic copolyester composites: fracture and failure behaviour

Abstract

Jute cloth reinforced, fully biodegradable thermoplastic composites were produced by the film stacking technique, with a semicrystalline copolyester (Ecoflex) as the matrix material. The jute cloth content varied between 0, 20 and 40 wt-% in the sheets produced by hot pressing. Specimens cut from the sheets were subjected to in plane static and out of plane dynamic loading, and the related fracture and failure behaviours were studied. The jute cloth proved to be a useful reinforcement to enhance in plane mechanical properties. The J integral concept (J–R curve) was adopted to assess the fracture behaviour of the composites. Crack propagation in single edge notched tensile (SEN-T) loaded specimens was detected using position resolved acoustic emission (AE). Acoustic emission was also used to characterise the failure. Surprisingly, no beneficial effect of the jute cloth was observed in the out of plane, namely instrumented falling weight impact (IFWI) test. This could be explained by the characteristics of the jute cloth used (the large mesh size increases the tendency to disintegrate when stretched at high strain rates) and by its moderate adhesion toward the matrix.     

表面处理对剑麻纤维布/不饱和树脂材料性能影响

采用碱、高锰酸钾及热对剑麻纤维布进行了表面处理,并由真空辅助树脂传递模塑成型(VARTM)工艺制备了剑麻纤维布增强不饱和聚酯树脂复合材料。通过对复合材料的力学性能及吸水性的测试,研究了不同剑麻纤维布表面处理对其不饱和聚酯树脂复合材料性能的影响。结果表明:经过碱处理,复合材料的拉伸、弯曲,冲击强度提高最大,可分别提高26.5%,16.5%和22.6%,吸水率降低了47.5%。对剑麻纤维布进行表面处理可使复合材料的界面性能得到改善,力学性能提高,吸水性降低。     

Mechanical properties of phenolic composites reinforced with jute/cotton hybrid fabrics

Mechanical properties (tensile, flexural, impact, and dynamic mechanical thermal analysis) of novolac type phenolic composites reinforced with jute/cotton hybrid woven fabrics were investigated as a function of fiber orientation and roving/fabric characteristics. Scanning electron microscopy (SEM) was carried out to investigate the fiber‐matrix adhesion. Results showed that the composite properties are strongly influenced by test direction and rovings/fabric characteristics. The anisotropy degree was shown to increase with test angle and to strongly depend on the type/architecture of fabric used, i.e., jute rovings diameter, relative fiber content, etc. It was possible to obtain composites with higher mechanical properties and lower anisotropy degree by producing cross‐ply laminates. Best overall mechanical properties were obtained for the composites tested along the jute rovings direction. Composites tested at 45° and 90° with respect to the jute roving direction exhibited a controlled brittle failure combined with a successive fiber pullout, while those tested in the longitudinal direction (0°) exhibited a catastrophic failure mode. Our results indicate that jute promotes a higher reinforcing effect and cotton avoids catastrophic failure. Therefore, this combination of natural fibers is suitable to product composites for lightweight structural applications. POLYM. COMPOS., 26:1–11, 2005. © 2004 Society of Plastics Engineers.     

Jute fiber reinforced polypropylene produced by continuous extrusion compounding,part 1: Processing and ageing properties

This article addresses the processing and ageing properties of jute fiber reinforced polypropylene (PP) composites. The composite has been manufactured by a continuous extrusion process and results in free flowing composite granules, comprising up to 50 weight percent (wt %) jute fiber in PP. These granules have similar shape and diameter as commercially available PP granules. Rheological analysis shows that viscosity of the compounds follows the same shear rate dependency as PP and is on the same level as glass‐PP compounds. The mechanical properties show very little variation and exhibit strength and stiffness values at the upper range of competing natural fiber reinforced compounds for injection molding. The mechanical performance reduces gradually upon prolonged thermal loading and immersion in water. The low water diffusion coefficient of the 50 wt % jute‐PP composites indicates that the fibers are not forming a continuous network throughout the polymer. The jute fibers exhibit a stabilizing effect against ultra violet irradiation (UV) on PP polymer and, as a consequence, the mechanical properties of jute‐PP composites hardly decrease during an accelerated UV ageing test. Bacteria, fungi, and garden mold grow easily on the compound material, but only have a limited effect on mechanical properties. The resistance to growth of bacteria on the materials surface can be increased using a biostabilizer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Studies of jute fiber composites with polyesteramide polyols as interfacial agent

Polyesteramide polyols have been synthesized by melt condenstion using a mixture of alkanolamines, polyethylene glycols, and dicarboxylic acids/anhydrieds, and the behavior or resin samples as interfacrial agents in unidirectional as well as random composites of jute/epoxy and jute/polyester has been evaluated. Mechanical properties of these composties with or without interfacial agents have been determined along with the effect of water uptake on such properties. The incorporation of polyesteramide polyol (PEAP) resins as interfacila agents has been found to significantly improcve the mechanical properties of jute fiber composites. It has also been found that increasing the hydroxyl value of PEAP results in a better bonding of the composities up to a certain optimum limit of hydroxyl value beyond which the molecular weight of the interfacila agent as well as its bonding strenght decreases. Use of PEAP resin of optimum hydroxyl value and molecular weight also significantly improves the water resistance capacities of jute/epoxy composites.     

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.