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, r <br /> 1� <br /> �h�'and. '� <br /> Ashland Specialty Chemical Company <br /> Division of Ashland Inc. <br /> Specialty Polymers&Adhesives Division Address Reply: <br /> 802 Harmon Avenue <br /> Columbus,OA 43223 <br /> Tel: (614)232-8510 <br /> Fax:(614)232-8520 <br /> Emulsion Polymer Isocyanate Adhesives: A Study of Longevity <br /> This report is a synopsis of work conducted by Edwin Luckman of Ashland Chemical Co. in 1995. <br /> ABSTRACT: <br /> Emulsion polymer isocyanate(EPI) adhesives have been marketed in the United States since 1979 <br /> and are used in many high performance applications bonding a wide variety of materials. This <br /> paper examines the longevity of EPI adhesives and the resulting adhesive bonds. Longevity, in <br /> adhesives, is measures the endurance of these bonds and consists of two parts: durability, which <br /> measures physical stability and permanence, which measures chemical stability. EPI adhesives <br /> were evaluated for durability and permanence using various ASTM test methods, industry <br /> standards, and in-service exposure tests. Conclusions from these evaluations are that EPI adhesives <br /> provide excellent degradation resistance to physical and chemical effects. Adhesive bonds formed <br /> with EPI adhesives are not sensitive to the chemical characteristics of wood, are resistant to the <br /> swelling and shrinking stresses of wood, and are resistant to chemical degradation. EPI adhesives <br /> provide excellent longevity under a wide variety of end-use conditions to meet the requirements of a <br /> changing market where quality is the primary criteria. <br /> LONGEVITY OF ADHESIVE BONDS: <br /> Testing of adhesives can be separated into three general categories: working properties of the <br /> adhesive, cured film properties, and determination of the quality and performance of the adhesive <br /> bonds. Working properties and cured film properties include such properties as viscosity, solids <br /> content, tensile strength, and elongation. Stability of the cured adhesive film against moisture and <br /> solvents is an important factor as well. <br /> A wide variety of test methods are used in a laboratory setting to confirm that adhesive bonds <br /> produced under a certain set of conditions will perform up to expectations. Most of these relate to <br /> subjecting the adhesive bonds to moisture, heat, or both and determining the amount of deterioration <br /> which took place. Once the strength of the bond has been established as well at its short term <br /> exposure to moisture and heat, it is essential to know how the laminated part will perform in service <br /> over a long period of time. Assessing the longevity of an adhesive generally is related to initially <br /> determining if the adhesive bond is durable and if it is permanent. <br /> Quality Plus: Headquarters: Tel: (614)790-3333 <br /> Ashland's Commitment to 5200 Blazer Parkway Fax: (614)790�119 <br /> Quality and Productivity Dublin,Ohio 43017 http://www.ashspeacom <br />