Mechanical Properties of Phenolic Resins

Table V. Effect of Resin Solids Content on Physical and Mechanical Properties of Phenolic Resins...

Dynamic mechanical analysis provides a useful technique to study the cure kinetics and high temperature mechanical properties of phenolic resins. The volatile components of the resin do not affect the scan or limit the temperature range of the experiment. However, uncured samples must be supported by a braid, a scrim, or paper. This does not influence the kinetic results and can be corrected in the calculations of dynamic mechanical properties (qv). Recent DMA work on phenolic resins has been used to optimize the performance of structural adhesives for engineered wood products and determine the effect of moisture in wood product on cure behavior and bond strength (75-77). 

Mathur R B, Singh B P, Dhami T L, Kalra Y, Lai N, Rao R and Rao A M (2010), Influence of carbon nanotube dispersion on the mechanical properties of phenolic resin composites , Polym Compos, 31, 321—327. 

In addition, blending with epoxy/amine blends has been reported as a suitable route to improve the mechanical properties of phenolic resins and to reduce the cure temperature [a.368]. The results reported demonstrate that the epoxy/amine content should be kept below 15 wt% to avoid a significant reduction of the thermal stability of the blend. Flame resistance experiments identified the aromatic diglycidyl ether of bisphenol-A-based (epoxy equivalent of 190 g/mol) epoxy/amine system as one of the best epoxy resins to produce thermally stable blends with the phenolic resol. 

Choi, M.H. In, J. Mechanical and thermal properties of phenolic resin-layered silicate nanocomposites synthesized by melt intercalation. J. Appl. Polym. Sci. 2003, 90 (9), 2316-2321. 

Yin, Q., Li, A., Wang, W. et al. 2007. Study on the electrical and mechanical properties of phenol formaldehyde resin/graphite composite for bipolar plate. Journal of Power Sources 165 717-721. 

Polynuclear Phenol—Glycidyl Ether-Derived Resins. This is one of the first commercially available polyfunctional products. Its polyfunctionahty permits upgrading of thermal stabiUty, chemical resistance, and electrical and mechanical properties of bisphenol A—epoxy systems. It is used in mol ding compounds and adhesives. 

Because of their favourable price, polyesters are preferred to epoxide and furane resins for general purpose laminates and account for at least 95% of the low-pressure laminates produced. The epoxide resins find specialised uses for chemical, electrical and heat-resistant applications and for optimum mechanical properties. The furane resins have a limited use in chemical plant. The use of high-pressure laminates from phenolic, aminoplastic and silicone resins is discussed elsewhere in this book. 

Effect of the phenolic resin content in the mechanical properties of nitrile rubber... 

Crosslinking, Thermal and Mechanical Properties of Thermoplastic and Phenolic Resin Systems A Bibliography1", PLASTEC Note 11 (1966) 16) N.E. Beach, Glossary of... 

Phenolic novolacs, 18 760-761 Phenolic resin adhesives, 18 783-784 Phenolic resin can coatings, 18 38 Phenolic resin composites, 18 792-794 Phenolic resin drying-oil varnishes, 18 783 Phenolic resin fibers, 18 797-798 mechanical properties of, 18 798 Phenolic resin foam, 18 795-796 Phenolic resin manufacturers, U.S., 18 774 Phenolic resin polymerization, 18 760-765 alkaline catalysts in, 18 762-765 neutral catalysts in, 18 761-762 strong-acid catalysts in, 18 760-761 Phenolic resin prepregs, 18 793 Phenolic resin production unit, 18 766 Phenolic resins, 10 409 18 754-755, 756-802 22 10 26 763 in abrasive materials, 18 786-787 in air and oil filters, 18 790 additional reactants in, 18 759 analytical methods for, 18 774-779 applications of, 18 781-798 batch processes for, 18 766 from biomass and biochemical processes, 18 769-770... 

Some satisfactory results were also obtained by modification of properties of phenol-formaldehyde resin (PFR) composites with the synthesized diallylsilazanes (scheme 1). Thas, addition of diallylsilazanes (1-3 mass %) to this composition has improved some of essential characteristics of hardened PFR (table 3). It should be noted that other important physical and mechanical properties of the composites have remained safe (table 3). 

Stager, H., W. Siegfried, and R. Sanger Chemical constitution and structure of phenolic resins. II. Mechanical properties in relation to structure. Schweiz. Arch, angew. Wiss. Tech. 7, 129, 153 (1941). 

Syntactic foams manufactured from hollow glass or silica microspheres and an epoxide, phenolic or other matrix resin represent a class of lightweight structural materials used for buoyancy purposes, insulation and packaging. The effect of silanes on the mechanical properties of syntactic foams at a nominal density of 0.35 g/cm3 is shown in Tables 14-16. The Proportional Limit is defined as the greatest stress which the foam is capable of sustaining without any deviation from proportionality of stress to strain (Hooke s Law). 

Figure 35. Mechanical properties of carbon/carbon epoxy-resin hybrid composites, compared with the properties of the composite skeletons before resin impregnation (61,62). The composite skeletons were prepared from Sigrafil HM 3 PAN-based fiber, rigidized with a phenolic resin, and densified by four cycles with coal-tar pitch plus sulfur the carbonization temperature was 1000°C. (a) Young s modulus.

Average physical and mechanical properties of the flakeboards are summarized in Table I. On the average, panels bonded with the lignin/phenolic resin... 

Physical and mechanical properties of the flakeboards are summarized in Table VI. On average, all strength properties decreased as the phenolic resin solids increased, with one exception (i.e., MOE at 46% resin solids). The effect of phenolic resin solid on the stability of the flakeboard was not significant (Table VI). 

Blends of elastomers are routinely used to improve processability of unvulcanized rubbers and mechanical properties of vulcanizates like automobile tires. Thus, cis-1,4-polybutdiene improves the wear resistance of natural rubber or SBR tire treads. Such blends consist of micron-sized domains. Blending is facilitated if the elastomers have similar solubility parameters and viscosities. If the vulcanizing formulation cures all components at about the same rate the cross-linked networks will be interpenetrated. Many phenolic-based adhesives are blends with other polymers. The phenolic resins grow in molecular weight and cross-link, and may react with the other polymers if these have the appropriate functionalities. As a result, the cured adhesive is likely to contain interpenetrating networks. 

Modification of the phenol ring can affect both the kinetics and the properties of the phenol-formaldehyde system. Substitution at the ortho and/or para position of the phenol will limit the extent of cross-linking and hence the mechanical properties of the cured phenolic resin. A summary of current work on these modified-classical phenolic resins is given. 

The mechanical properties of the C3, C6, and Cl2 nanocomposites were all significantly better than those of the neat phenolic resin, even if a very small amount of the silicate was used. Among the nanocomposites prepared, the organically modified MMT-resol systems showed better mechanical properties than those of the unmodified MMT-resol system. This improvement was attributed to the formation of an end-tethered structure due to the reaction of the carboxylic acid of the organic modifier with the methylol group of the phenolic resin. Thermogravimetric analysis reported by Byun and coworkers showed that the nanocomposite systems had similar thermal stability to that of the neat polymer. 

The development of ACF and AC cloths is closely related to that of carbon fibers (CFs). This makes that the raw materials used for the preparation of ACFs be, chronologically, the same as for CFs. Thus, in 1966, viscose and acetate cloths were, like for CFs, the first materials used to obtain ACFs [4, 5]. The low yield of the ACFs, and CFs, obtained from the above precursors, oriented the research towards the seek of other raw materials for the preparation of cheaper CFs and ACFs with a higher yield. In this way, ACFs were prepared from 1970 using lignin (with the brand of Kayacarbon ALF), polyvinylchloride [6] (i.e., Saran polymer, already used to obtain ACs) and phenolic precursors [7]. The high yield and the good mechanical properties of the ACFs obtained make these precursors very useful for this application. In fact. Economy and Lin [8] developed ACFs from a phenol formaldehyde precursor, which are commercialized since 1976 under the name of Novolak. In 1980, Kuray Chemical Co. Ltd commercialized ACFs from phenolic resin under the name of Kynol. ... 

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