Polyester-based composites properties

Growing awareness in maintaining a healthy environment has resulted in the development and implementation of eco-friendly products. Biodegradable polyester based composites are widely used in biomedical and commodity applications, because of their degradability and non-toxic properties. 

Biodegradable polyester-based composites have been extensively studied for use in medical applications owing to their biocompatible and degradable properties in the human body. The major reported examples in biomedical products are fracture-fixation devices, such as sutures, screws, micro titration plates, and delivery systems [77]. Cellulosic nanofiber reinforced PLA composite materials... 

A wide range of biodegradable polyester-based composites is available in the new era of novel materials. Polyester-based composites are mainly manufactured by reinforcing with glass/carbon and natural fibers. The use of natural fibers as reinforcement has increased in the last two decades, because of their easy availability and degradable property. Polyester composites reinforced by glass or carbon fibers... 

Composite Particles, Inc. reported the use of surface-modified rubber particles in formulations of thermoset systems, such as polyurethanes, polysulfides, and epoxies [95], The surface of the mbber was oxidized by a proprietary gas atmosphere, which leads to the formation of polar functional groups like —COOH and —OH, which in turn enhanced the dispersibility and bonding characteristics of mbber particles to other polar polymers. A composite containing 15% treated mbber particles per 85% polyurethane has physical properties similar to those of the pure polyurethane. Inclusion of surface-modified waste mbber in polyurethane matrix increases the coefficient of friction. This finds application in polyurethane tires and shoe soles. The treated mbber particles enhance the flexibility and impact resistance of polyester-based constmction materials [95]. Inclusion of treated waste mbber along with carboxyl terminated nitrile mbber (CTBN) in epoxy formulations increases the fracture toughness of the epoxy resins [96]. 

Polyester polyols, 25 464 468 Polyester resin(s), 11 302 coating resins, 7 104-106 cyclopentadiene and dicyclopentadiene applications, 8 230 flammability of, 20 115-116 properties in powder coating, 7 43t standard test methods for, 20 11 It unreinforced, 10 187t weathering of, 20 116 Polyester resin-based powder coatings, organic titanium compounds in, 25 125 Polyester resin composites, 26 762-763 Polyester resin formulations ingredients of, 20 96t unsaturated, 15 511-512 Polyesters, 10 185-189, 497 12 655-656. See also Thermoplastic polyesters Unsaturated polyesters acid resistance of, 20 7-8 antioxidant applications, 3 121 aromatic ionic, 23 722 based on 1,4-cyclohexanedimethanol, 12 674-675... 

The use of maleic anhydride as a compatiblizer between wood particles and bisphenol A-based polyesters resins has been investigated (Han etal., 1991). In this study, the MA was added directly to the composition of woody matrix filler and resin rather than by pre-modification of the wood. It was found that composite properties were improved by addition of MA, probably due to esterification of the wood occurring during the kneading process. The modification of sawdust using maleic anhydride has been performed in order to provide a compatible filler for polyester resins (Marcovich etal., 1996). Modification was performed at room temperature using a solution of maleic anhydride in acetone, in some cases catalysed with sulphuric acid. It was claimed that bonding occurred under these mild conditions from IR spectroscopic evidence only. 

The composition and structure of the polyester polyols lead to polyurethanes with distinct properties. These polyester-based polyurethanes have specific applications, as shown in Table 8.5. 

The syntheses, properties and applications of hyperbranched polyesters have been investigated in great detail [22]. The addition of hyperbranched polyesters was reported to double the interlaminar fracture resistance of epoxy-based composites and to reduce the internal stress level by as much as 80% in the pres-... 

From Table X, the IPDI based oligomers have better solvent resistance than the TDl based ones. IFDl based oligomers also appear to exhibit better adhesion. Other properties are not affected by dllsocyanate choice. Polyester based materials seem to give better flexibility and solvent resistance than polyether based urethanes (Table XI). The branched polyether in composition N gives better adhesion and solvent resistance than the linear polyether. 

Biodegradable Polyester-Based Blends and Composites Manufacturing, Properties, and Applications... 

P(l) Phenolic resins should be considered when the overriding emphasis is on performance nnder heat, retention of properties under lire conditions or low emission of toxic fumes (about 10% that of an isophthalic polyester based glass FRP). The attractive characteristics of composites made from phenolic resins are low flammability, low spread of flame and little smoke. The resole phenoUcs allow similar curing to polyesters with the addition of an acid based catalyst or heat. Though cure at room temperature is possible, an elevated temperature post cure above 80°C is required to obtain dimensionally stable materials. The use of acid based catalysts may lead to moulding tool corrosion. 

The popularity of polyester in reinforced plastics is based on its ease of use, low cost and the ability to produce good composite properties after room temperature curing, it has good structural properties, which make it possible to produce large, complex mouldings, such as boat hulls, in one piece. Many application processes are relatively cheap, which means that even small series of mouldings can be manufactured cost-effectively. 

M. Krouit, M.N. Belgacem and J. Bras, Chemical versus solvent extraction treatment Comparison and influence on polyester based bio-composite mechanical properties. Compos. A 41,703-708 (2010). 

Singha, A.S., Rana, A.K., Jarial, R.K. Mechanical, dielectric and thermal properties of Grewia optiva fibers reinforced unsaturated polyester matrix based composites. Mater. Des. 51, 924-934 (2013)... 

All these studies show that many dimer acid-based polymers are based on the flexural and adhesion properties of dimer acid. A considerable amount of work has been reported on polyesters as well as other polymers. Among the polyesters based on dimer acid s versatile composition are those used to achieve high performance speciality polyesters. Efforts are made only to increase molecular weight little effort has been made to prepare polyesters of low molecular weight useful as plasticizers. A couple of references [88,89] describe the preparation of plasticizers comprising glycidyl esters of dimer acid and epoxy resin compositions containing them. 

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