Surlyn Ionomer resin

TPO-based ionomers have been used in abrasion-resistant automotive exterior applications for a number of years. More recently, Du Pont s Bexloy W, a TPO based on the company s Surlyn ionomer resin, has been employed in competition with conventional TPOs (EPDM/PP compounds) in automotive applications such as fender flares, air dams, and license-plate brackets. 

DuPont Surlyn ionomer resins, listed below, are crystal clear and are used alone or in combination with other resins f ° ]... 

Ionomer resins consisting of ethylene—methacrylic acid copolymers partially neutralized with sodium or zinc were commercially introduced in 1964 by Du Pont under the Surlyn trademark (1). More recently, a similar line of products, sold as Hi-Milan resins, has been commercialized by Mitsui—Du Pont in Japan. Iolon ionomeric resins, based on ethylene—acrylic acid, are produced by Exxon in Belgium. Ionomers containing about 1 mol % of carboxylate groups are offered by BP in Europe as Novex resins. Low molecular weight, waxy Aclyn ionomers are produced and sold by AlliedSignal. 

Surlyn 7930 Lithium grade ionomer resin E. I. du Pont de Nemours... 

The major suppliers of ionomer resins include Du Pont (Surlyn A) and Union Carbide (Bakelite). 

Ali [89] reported the results of a study on a LDPE blend with an ionomer resin based on ethylene-methacrylic acid copolymer (Surlyn 1857 10 wt%), which also contained citric acid (1 wt%) as a blowing agent. The blend, as well as the reference samples of pure LDPE and LDPE/citric acid, were e-beam-irradiated at room temperature with a dose of 40kGy, and the EPR spectra were recorded at different time intervals after irradiation. The septet corresponding to allyl radicals was a dominant spectral component in the initial spectra, the total radical concentration being about 10% higher in the presence of the ionomer due to a contribution of Surlyn-derived radicals. The latter were more stable, such that in the blend the EPR signal was still observed three days after irradiation, whereas in the reference samples the radicals had decayed completely within 3.5 h. 

The Surlyn A ionomers (E. I. du Pont de Nemours Co.) are believed to be derived from copolymers of ethylene with minor amounts of methacrylic acid which are treated subsequently, so that substantial amounts of the carboxylic acid are converted to the sodium or other metal carboxylate. Resins similar to the one studied in this work contain about 10 weight % methacrylic acid. The ash (sodium carbonate) indicates about 40% neutralization. This resin, which contains 0.05% Santo-white Powder (Monsanto Chemical Co.), a phenolic antioxidant, is of medium molecular weight—i.e., probably corresponding to an ethylene homopolymer with a melt flow index around 20 (17). The molecular weight distribution is broad (17). 

In view of the similarity in behavior of the networks in the ionomer and low density resin, we are able to deduce from modulus and elongation at rupture measurements the relative crosslinking rates. It appears that Surlyn A crosslinks 50 to 60% more rapidly than DFD 6040. The increased crosslinking in the ionomer may be associated with the radio-... 

Several organic sealants such as epoxy resins, butyl rubber or silicones prove to be more or less permeable and the tiny amount of solvent in the cell is rapidly lost. Suitable organic sealing materials for this technology turn out to be thermoplastic materials, like polyethylene/carboxylate copolymers. So far, Surlyn 1702 ionomer from Dupont has been the main substance used to optimize cell performance and build module prototypes. However, the softening point of Surlyn is rather low (65° C) and at elevated temperatures (> 70°C), serious solvent loss is observed because the bond between Surlyn and TCO-coated glass is substantially weakened [7]. 

The term ionomer was first introduced in the early 1960s, when DuPont developed Surlyn resins [36], salt forms (Na and Zn) of the copolymers of ethylene and a small amount (several mole percent) of methacrylic acid. Initially, Surlyn resin that was based on polyethylene was called an ionomer, but later all polymers that have a small amount of ionic groups (up to 10-... 

This versatile technique is generally used where a ply of polyethylene or copolymer thereof is required in a structure. Other polymers may be used in specialized areas but the handling can become more difficult. The process is widely used within the Packaging Industry for the coating of paper, board, foils, cellulose film and thermoplastic films. The most common coating resin used is low-density polyethylene, but this now extends to copolymers such as Ethylene-vinyl acetate, ethylene-acrylic acid, polypropylene, high density polyethylene and ionomers (e.g. Surlyn). The acrylic acid-based materials and ionomers are used in areas in which enhanced adhesive strength is required, such as resistance to difficult environments. 

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