Thermoplastic adhesives properties

The data also demonstrate that the addition of the thermoplastic, PMMA, does not have the significant effect on the toughness or adhesion properties as does the addition of the rubber, Vamac B-124. Clearly, the physical properties of the polymeric additive determine the magnitude of the adhesive physical property modifications, which result from their addition to an alkyl cyanoacrylate monomer. 

Many engineering thermoplastics (e.g., polysulfone, polycarbonate, etc.) have limited utility in applications that require exposure to chemical environments. Environmental stress cracking [13] occurs when a stressed polymer is exposed to solvents. Poly(aryl ether phenylquin-oxalines) [27] and poly(aryl ether benzoxazoles) [60] show poor resistance to environmental stress cracking in the presence of acetone, chloroform, etc. This is expected because these structures are amorphous, and there is no crystallinity or liquid crystalline type structure to give solvent resistance. Thus, these materials may have limited utility in processes or applications that require multiple solvent coatings or exposures, whereas acetylene terminated polyaryl ethers [13] exhibit excellent processability, high adhesive properties, and good resistance to hydraulic fluid. 

Polysulfide resins combine with epoxy resins to provide adhesives and sealants with excellent flexibility and chemical resistance. These adhesives bond well to many different substrates. Tensile shear strength and elevated-temperature properties are low. However, resistance to peel forces and low temperatures is very good. Epoxy polysulfides have good adhesive properties down to -100°C, and they stay flexible to -65°C. The maximum service temperature is about 50 to 85°C depending on the epoxy concentration in the formulation. Temperature resistance increases with the epoxy content of the system. Resistance to solvents, oil and grease, and exterior weathering and aging is superior to that of most thermoplastic elastomers. 

Acrylonitrile-Butadiene-Styrene (ABS). ABS plastics are derived from acrylonitrile, butadiene, and styrene. ABS materials have a good balance of physical properties. There are many ABS modifications and many blends of ABS with other thermoplastics that can affect adhesion properties. ABS resin can be bonded to itself and to other materials with adhesives, by solvent cementing, or by thermal welding. 

Poly(ester-imide)s are a class of polymers known for more than 35 years. They are used today in large tonnage as electrical insulating materials. The patent literature reviewed shows that predominant research activities in the past were focused on improving the electrical, thermal and mechanical properties. In recent times new applications for these polymers have been found, such as engineering thermoplastics, adhesives, printed circuit boards and membranes. Excellent properties and easy processing will probably lead to a continuous growth of poly(ester-imide) business. 

Polyolefin - Polyolefins are a large class of carbon-chain elastomeric and thermoplastic polymers usually prepared by addition (co)polymerization of olefins or alkenes such as ethylene. The most important representatives of this class are polyethylene and polypropylene. There are branched and linear polyolefins and some contain polar pendant groups or are halogenated. Unmodified polyolefins are characterized by relatively low thermal stability and a nonporous, nonpolar surface with poor adhesive properties. Processed by extrusion, injection molding, blow molding, and rotational molding. Other thermoplastic processes are used less frequently. This class of plastics is used more and has more applications than any other. Also called olefinic resin, olefinic plastic. 

The more viscous, mastic-type cements include some of the epoxies, urethanes and sflicones. Epoxies adhere well to both thermosets and thermoplastics. But epoxies are not recommended for most polyolefin bonding. Urethane adhesives have made inroads into flexible packaging, the shoe industry, and vinyl bonding. Polyester-based polyurethanes are often preferred over polyether systems because of their higher cohesive and adhesive properties. Sflicones are especially recommended where both bonding and sealing are desired. 

Polyester polyols are used widely in urethane adhesives because of their excellent adhesive and cohesive properties. Compared to polyether-based polyols, polyester-based polyol adhesives have higher tensile strengths and improved heat resistance. These benefits come at the sacrifice of hydrolytic resistance, low-temperature performance, and chemical resistance. One of the more important application areas for these products is in the solvent-borne thermoplastic adhesives used in shoe sole binding. These products are typically made from adipic acid and various glycols (see Fig. 15). 

Features Curing agent for maintenance and marine coatings, overprint varnishes, masonry and pool coatings, adhesives, caulks, grouts flexibilizer for thermoplastic polyamides Properties Gardner < 9 cotor dear appearance dens. 8.1 Ib/gal vise. 150,000 poise amine no. 85-95 flash pt. (CC) > 160 C 100% solids Epikure 3100-ET-60 [Resolution Perl. Prods.]... 

Features Exc. adhesion soft, clear, glossy, flexible but though films wash resist, when crosslinked thermoplastic crosslinkable Properties Opaque dens. 8.72 Ib/gal vise. 100 cps pH 8 VOC 183 g/l anionic 30% solids... 

CAS 12001-26-2 EINECS/ELINCS 310-127-6 Uses Filler for joint compds., adhesives, sealants, electrode coatings reinforcing agent (inc. stiffness, prevents waqting, improves dimensional stability) in thermoplastic resin composites insulator aiding dielec, props, in thermoset resin composites Features Reduces shrinkage, cracking in adhesives Properties 48 p median size bulk dens. 21 Ib/fE... 

The water-based component is the main adhesive component in EPI adhesives. Generally, it consists of water, poly(vinyl alcohol) (PVA), one or more water-based emulsions, filler(s) and a number of additives such as defoamers, dispersing agents and biocides [1, 4, 5, 8, 9]. As with traditional thermosetting and thermoplastic wood adhesives, properties such as viscosity and solids content vary with the intended application. In the European market the typical viscosities are 2000-8000 mPa s at 25°C and the solids content is normally 50% or more. The adhesives are normally neutral with a pH in the range of 6-8 [3]. The storage stability of the EPI adhesive component is typically half a year when stored at a temperature between 10 and 30°C. 

This is one of the most important synthetic thermoplastic elastomers. Nitrile rubber is a copolymer of butadiene and acrylonitrile. The copolymer usually contains enough acrylonitrile (>25%) so that good resistance to oil and grease can be obtained. Adhesive properties also increase with increasing nitrile content. These adhesives are used to bond vinyls, other elastomers, and fabrics where good wear, oil, and water resistance are important. Compatibility with additives, fillers, and other resins is another advantage of this material.Table 5.1 summarizes the properties of nitrile rubber. 

Thermoplastic adhesives have a more limited temperature range than thermosetting types. It is not suggested to use thermoplastic adhesives over 65°C. Their physical properties vary over a wide range, because many polymers are used in a single-adhesive formulation. 

Adhesive Processes. Most commercially available adhesive systems consist of either thermoplastic hot melt or reactive thermosetting resins. Typical thermoset adhesive formulations contain base resin monomers and oligomers, curing agents (hardeners), catalysts, adhesion promoters, and various fillers. Adhesive properties depend on the complete mixing and adequate dispersion of the... 

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