Fiber-reinforced polymers phenolic

The mechanical properties of fiber-reinforced polymer composites are cmitroUed by factors such as nature of matrix, fiber—matrix interface, fiber volume or weight fraction, fiber aspect ratio, etc. Due to the hydrophilic nature, the fibers pulled out from polyester and polyethylene matrices, they were compared with the fibers pulled out from the epoxy matrix, which carry polymer particles on their surfaces. On the other hand, fracmre of the fibers occurs at the crack plane in phenolic composites. From SEM microstructures of different composites, it was observed that the bonding of sisal fiber with the four matrices are found to be in the order of phenolic > epoxy > polyester > polyethylene [58, 59]. 

Chapter 5 summarizes the investigation of lignocellulosic flax fiber-based reinforcement requirements to obtain structural and complex shape polymer composites. This chapter discusses in detail the possibility of forming complex shape structural composites which are highly desirable for advanced applications. Chapter 7 focuses on the structure and properties of cellulose-based starch polymer composites, while Chapter 8 focuses on the spectroscopic analysis of rice husk and wheat gluten husk-based polymer composites using computational chemistry. Chapter 9 summarizes the processing, characterization and properties of oil palm fiber-reinforced polymer composites. In this chapter, the use of oil palm as reinforcement in different polymer matrices such as natural rubber, polypropylene, polyurethane, polyvinyl chloride, polyester, phenol formaldehyde, polystyrene, epoxy and LLDPE is discussed. Chapter 10 also focuses on... 

Phenolic resins as a matrix material in advanced fiber-reinforced polymer (FRP)... 

Most processors of fiber-reinforced composites choose a phenol formaldehyde (phenoHc) resin because these resins are inherently fire retardant, are highly heat resistant, and are very low in cost. When exposed to flames they give off very Htde smoke and that smoke is of low immediate toxicity. PhenoHc resins (qv) are often not chosen, however, because the resole types have limited shelf stabiHty, both resole and novolac types release volatiles during their condensation cure, formaldehyde [50-00-0] emissions are possible during both handling and cure, and the polymers formed are brittle compared with other thermosetting resins. 

Some of the common types of plastics that are used are thermoplastics, such as poly(phenylene sulfide) (PPS) (see POLYMERS CONTAINING SULFUR), nylons, liquid crystal polymer (LCP), the polyesters (qv) such as polyesters that are 30% glass-fiber reinforced, and poly(ethylene terephthalate) (PET), and polyetherimide (PEI) and thermosets such as diallyl phthalate and phenolic resins (qv). Because of the wide variety of manufacturing processes and usage requirements, these materials are available in several variations which have a range of physical properties. 

FRP materials are made up of the polymer and reinforcing fibers. The polymer is typically a thermoset polymer thermoplastics can be used as well. Some typical thermoset polymers used are epoxy resins, unsaturated polyester resins, epoxy vinyl ester resins, phenolic resins, and high performance aerospace resins such as cyanate esters, polyimides, and bismaleimides. These resins... 

Substrates used included fiber-reinforced epoxy base polymer [FRP], nylon 66, polytetrafluoroethylene [Teflon], poly(ethylene terephthalate) [PET], phenolic resin, and thermoplastic polyimide [ULTEM, GE]. FRPs were the primary substrates used. Initially, they were cleaned with detergent in an ultrasonic bath followed by rinsing with deionized water and alcohol. For further cleaning, they were treated with oxygen plasma (1.33 seem, 60 W, 5 min) followed by a hydrogen plasma treatment (3 seem, 60 W, 5 min). 

Organic matrices are divided into thermosets and thermoplastics. The main thermoset matrices are polyesters, epoxies, phenolics, and polyimides, polyesters being the most widely used in commercial applications (3,4). Epoxy and polyimide resins are applied in advanced composites for structural aerospace applications (1,5). Thermoplastics Uke polyolefins, nylons, and polyesters are reinforced with short fibers (3). They are known as traditional polymeric matrices. Advanced thermoplastic polymeric matrices like poly(ether ketones) and polysulfones have a higher service temperature than the traditional ones (1,6). They have service properties similar to those of thermoset matrices and are reinforced with continuous fibers. Of course, composites reinforced with discontinuous fibers have weaker mechanical properties than those with continuous fibers. Elastomers are generally reinforced by the addition of carbon black or silica. Although they are reinforced polymers, traditionally they are studied separately due to their singular properties (see Chap. 3). 

This chapter will deal with the chemistry and applications of epoxies, phenolics, urethanes, and a variety of current vogue high-temperature polymers. Applications in fiber-reinforced plastics will be discussed in the individual sections on resin chemistry where appropriate. Separate sections will deal with adhesives and sealants. Adhesives are most important because, as early history demonstrates, they led the way to the application of resins in aerospace. A section is also included on silicone and polysulfide sealants. Although these materials are elastomers rather than resins, no discussion of aerospace polymers would be complete without some mention. Some major thermosetting polymers have been omitted from this review. Among these are the unsaturated polyesters, melamines, ureas, and the vinyl esters. Although these products do find their way into aerospace applications, the uses are so small that a detailed discussion is not warranted. 

Chen, F. and Jones, F. R., Injection moulding of glass fibre reinforced phenolic composites 1. Study of the critical fibre length and the interfacial shear strengtli, Plast., Rubber Composites Proc. Appl, 23, 241 (1995). Termonia, Y., Structure-property relationships in short-fiber-reinforced composites, J. Polym. Set, Polym. Phys. Ed., 32, 969 (1994). 

Chem. Descrip. y-Ureidopropyltrimethoxysilane CAS 23843-64-3 EINECS/ELINCS 245-904-8 Uses Adhesion promoter aiding bond between fillers and reinforcements (e.g., fiberglass, particulates, metals) and various polymers (phenolic, urea-melamine, epoxies, polyamide, PU), for use in glass fiber sizes and finishes, wool insulation resin binders, primers, foundry sand binders, adhesives, sealants, and abrasive grinding wheel binders Features Contains no flamm. or combustible solv. low VOC emissions Properties Lt. straw clear liq. sol. in methanol, ethanol, acetone, toluene, methyl Cellosolve, water m.w. 220 sp.gr. 1.15 b.p. 217-250 C (700 mm Hg) flash pt. (TCC) 99 C ref. index 1.386 100% act. Silquest Y-11597 [OSi Spec.]... 

Uses Adhesion promoter aiding bond between fillers and reinforcements (e.g., fiberglass, particulates, metals) and various polymers (phenolic, urea-melamine, epoxies, polyamide, PU) used in glass fiber sizes and finishes, wool insulation resin binders, primers, foundry sand binders, adhesives, sealants, and abrasive grinding wheel binders low VOC emissions... 

Figure 1 Cost-related (specific) flexural strength of major thermoplastics, versus cost-related (specific) thermal tolerance. The unit cost is the market price in US cents (1992) of 1 cm plastics. The thermal tolerance is the temperature difference (AT) over room temperature (AT — T - room T), by which temperature (7 ) the flexural modulus is equal to 1 GPa. Designations, abbreviations WFRP-S, wood fiber reinforced PP (S type) of AECL, Canada (See Table 1) PMMA, polymethylmethacrylate PVC, pol)winyl chloride PS, polystyrene PP, polypropylene UP, unsaturated polyesters PA-GF, glass fiber (35%) reinforced polyamide PHR, phenolic resin EP, epoxy resin ABS, acrylonitrile/butadiene/styrene copolymer UF, urea/formaldehyde LDPE, low density polyethylene PC, polycarbonate POM, polyoxymethylene CAB, cellulose acetate butyrate LCP, liquid crystal polymers PEEK, polyether-etherketone PTFE, polytetrafluorethylene.

Ma C M, Lee C and Wu H (1998), Mechanical properties, thermal stability, and flame retardance of pultruded fiber-reinforced poly(ethylene oxide)-toughened novolak-type phenolic resin , J Appl Polym Sci, 69, 1129-1136. 

Zhou G, Movva S L and Lee J (2008), Nanoclay and long-fiber-reinforced composites based on epoxy and phenolic resins , J Appl Polym Sci, 108, 3720-3726. 

Joseph S, Thomas S. Electrical properties of banana fiber-reinforced phenol formaldehyde composites. J Appl Polym Sci 2008 109 256. 

Cellulose fibers in the form of papers and cotton had been used in combination with phenol-formaldehyde polymer as one of the earUest fiber-polymer composites [12]. Glass fibers later came on the scene and contributed to the commerciahzation of fiber-reinforced plastics [13]. The technical appHcations of fiber-reinforced plastic composites are shown in Figure 13.2. At least 50% of the fiber-reinforced plastics is used for automotive and construction applications. 

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