Polyamides adhesives

When the epoxy adhesive cannot be made flexible enough, the thermal conductivity and thermal expansion coefficient are controlled by appropriate fillers. General-purpose room temperature cured epoxy-polyamide adhesive systems can be made serviceable at low temperatures by the addition of appropriate fillers to control thermal expansion. 

The hostility of certain moisture environments can be seen in Fig. 15.11 Aluminum joints were bonded with room temperature curing epoxy-polyamide adhesive and aged in a hot, wet (tropical) environment and in a hot, dry (desert) environment. Excellent durability is achieved under dry conditions while significant degradation is caused by the wet conditions. 

Fillers are often useful in epoxy-polyamide adhesives (41). Fillers aid flow control—particularly at elevated temperatures. Other properties contributed by fillers are exhibited in the cured system. For example, they can increase the modulus of elasticity, modify the coefficient of thermal expansion, increase heat resistance, and even affect bond strength. Of course, the excellent wetting properties of polyamides Increase the dispersion efficiency of these fillers. The type of filler selected and the amount used also have a pronounced effect on adhesive quality. A few of these effects are illustrated in Tables VI and VII (37). (See also Table VIII.)... 

Note Material bonded, aluminum alloy sheet, 0.5 mm pretreatment, pickling method cure, 300 °F, 20 min base resins, Versamid resin 115 epoxy 60 40 . These same tables. Including Table VIII, illustrate the general property ranges to expect from epoxy-polyamide adhesives under defined cure and testing conditions (42). ... 

Polyamide-adhesives have thermal endurance at temperatures greater than SOOT (260°C) that is unmatched by any commercially available adhesive. Their short-term exposure at lOOOT (538°C) is slightly better than the epoxy-phenolic alloy. 

CAS 7128-64-5 EINECS/ELINCS 230-426-4 Uses Fluorescent whitener, optical brightener for thermoplastics (PVC, PE, PP, cellulose acetate, PS, PC, acrylics, polyolefins, PU, linear polyester, polyamides), adhesives, coatings, printing inks (for security bonds, bank notes), dyes, textiles (syn. fibers incl. PVC and acetate), molded articles, films, sheets, syn. leather, waxes, fats, and oils tracer in clear coatings... 

Epoxy-polyamide and epoxy-polysulfide adhesives have been used successfully for bonding properly treated PC l EE. An epoxy-polyamide adhesive (Epon 828/Versamid 125 60 40 ratio) cured for 16 hours at room temperature and followed by 4 hours at 74 C has given tensile-shear strengths of... 

D. M. Brewis, J. Comyn, and R. J. A. Shalash, The effect of moisture and temperature on the properties of an epoxide-polyamide adhesive in relation to its performance in single lap joints, Int. J. Adhes. Adhes. 2, 215 (1982). 

Fig. 2.17. Strengths of some single lap joints of aluminium bonded with an epoxy-polyamide adhesive on exposure to air at 43°C and 90% relative humidity for various times. Metal surface treatments are etching in chromic-sulphuric acid, O alkaline etching, solvent degrease, and phosphoric acid etching, (after Butt and Cotter ).

Although the dicarboxylic acids do not occur in appreciable amounts as components of animal or vegetal lipids, they are in general important metabolic products of fatty acids since they originate from byoxidation. Dicarboxylic acids are suitable substrates for preparation of organic acids for the pharmaceutical and food industries. Furthermore, they are useful materials for the preparation of fragrances, polyamides, adhesives, lubricants, and polyesters. 

Figure 4 Plot of bond strength against (1 + cos 6) on polyethylene using epoxy-polyamide adhesive of surface free energy 41.7 erg/cm (taken from reference 10).

Nitrile rubber adhesives have been used to bond medium-to-high polarity rubbers with polyamide substrates. In an early work, nitrile rubber in solvent was treated with 10-20 parts of phosphoric acid at 50-100°C and subsequently neutralized. In more recent work, acrylic acid, methacrylic acid, dicumyl peroxide and phenol ether were added to a mixture of nitrile and formaldehyde-phenol oligomer to give a mbber-to-polyamide adhesive. 

A higher service temperature product assembly adhesive can be formulated by using an ethylene acid copolymer such as Elvax II 5550. These adhesives approach the higher service temperature of polyamide adhesives, and thus are a low cost alternative in many applications. A typical formulation is shown in Table 16. 

Simple abrasion is usually a very poor surface treatment for fluorocarbon polymers. This may be seen from the results shown in Table 4.2 where joint strengths for PTFE and PCTFE, bonded using an epoxy-polyamide adhesive, are given and the fluorocarbons have been pretreated by either abrasion or a... 

Degussa Corporation, 1992, Precipitated Silicas, Manufacturing /Properties / Applications. Dexheimer, R.D.,and Vertinik, L.R., 1977, " Polyamide Adhesives", Handbook of Adhesives, 2nd ed., I. Skeist(ed.), Van Nostrand Reinhold, New York, pp 581-591. 

Fig. 109. Equation of McAbee et al. (1970) illustrated by failure times of an epoxy polyamide adhesive (Courtesy, Ministry of Defence, RAE, Famborough).

The polyamide terpolymers 6,6-6,6-10, 6,6-6,12 6,6—6,6—12 and 6,6—9,6—12 are used for bonding textile fabrics where they are resistant to washing and dry cleaning solvents. Polyamide adhesives have been reviewed by Rossitto (1990). 

Brewis et al. (1982) reported the dependence upon temperature of the tensile modulus of the epoxide-polyamide adhesive FMIOOO, which has a Tg of 40°C. The data that appear in O Fig. 18.9 show typical viscoelastic behavior. The same authors (1983) showed similar data for an aliphatic amine-cured epoxide adhesive, which has a Tg of 65°C. Changes in the strengths of lap joints with increasing temperature fell in the same manner as the modulus and tensile strength of the adhesive, as is shown in Fig. 18.10. 

Effect of temperature on the modulus of the epoxide-polyamide adhesive FM 1000 (Brewis et al. 1983]... 

Effect of high humidity (97% r.h. at 43°C) on the strength of aluminium joints bonded with an epoxide polyamide adhesive. After Butt and Cotter (1976). Surface treatments are o chromic-sulphuric acid etch, alkaline etch (commercial formulation], solvent degrease,... 

Epoxy polyamide adhesive of two components able to cure at room temperature... 

Such boring bars have internal structures in order to keep the core constructed with four carbon steel parts bonded by VEM in the tube part of the bar as shown in Fig. 5.20. A sheet of VEM is adhered on the periphery of the core and the core is inserted into the bar tube and then bonded by an epoxy-polyamide adhesive. In addition, the boring bar is completed with a tool-point part bonded on it. The reason why the core is divided into 4 parts is to prevent the occurrence of aeolotropy of the damping ability of the bar. 

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