Adhesives historical development

An important historic development was the insight that surface tension is a surface- and not a bulk-property. Newton ) had already discriminated between cohesive and adhesive forces. A decisive discriminative experiment was carried out by Hawksbee ). He investigated liquid rise in capillaries and between glass plates and found that the thickness of the glass did not matter. So the phenomenon of wetting was established as a surface phenomenon, although the depth of the interactions responsible for the various tensions still remains an issue today (chapter 2). 

Table 1.2 Historical developments for adhesives used in electronics...

Historical Development of Adhesives and Adhesive Bonding Fred A. Keimel... 

Most historical surveys treat the work of McBain and Hopkins in 1925 as the earliest application of modern scientific investigation to the study of adhesion [9]. McBain and Hopkins considered that there were two kinds of adhesion, specific and mechanical. Specific adhesion involved interaction between the surface and the adhesive this might be chemical or adsorption or mere wetting. Specific adhesion has developed into the model we today describe in terms of the adsorption theory. 

Table 1.2. Historical Developments for Adhesives Used in Electronics...

Many of the comments about the use of adhesives in building apply equally to civil engineering. The section on Historical Development outlined some of the uses of natural adhesives, for joining wood or... 

The use of adhesives can be traced back many centuries, while the production of adhesives, on an industrial scale, started about 300 years ago. The birth of modern structural adhesives can be dated from about 1910, with the introduction of the phenol-formaldehyde resins.Table II summarizes the historical development of structural adhesives, with the dates referring to the approximate time period during which each adhesive became commercially available. The introduction dates for the high-temperature polymers (polyimide, polybenzimidazole, and polyquinoxa-line) have been included for reference, although, as previously mentioned, there are presently few commercial products based on these polymers. 

The most common test specimen used is some form of overlap shear joint. While this provides information useful for comparative purposes, it gives little information of use to the design engineer. The value of test results in making predictions of durability depends on establishing a correlation between the behavior of test specimens under the test conditions and the service performance of bonded assemblies. Minford has reviewed the historical development of stressed test methods. Some of the more recent developments for predicting the strength and endurance of adhesively bonded metal joints have been surveyed by Aker. ... 

Keimel, E.A., Historical development of adhesives and adhesive bonding, in A. Pizzi and K.a L. Mittal (Eds.), Handbook of Adhesive Technology (pp. 3-15), Marcel Dekker, New York, 1974. 

In Chapters 3 and 6 we have briefly presented the most important theories for estimating interfacial tensions as well as their applications to wetting, adhesion and surface analysis. In this chapter we discuss the historical development of these theories and evaluate their applicability from a wider point of view. 

Contemporary discussion of the fundamentals of adhesion generally reflects the historical development of the subject. For convenience, this approach will be adopted here. Early work in the 1920s discussed two kinds of adhesion. Where surfaces were smooth, what would now be described as adsorption theory applied, with rough or porous surfaces mechanical theory. The next two sections, Sects. 2.2 and 2.3, of this chapter discuss these in turn. 

The military has historically led the way in the development and application of adhesive bonding on aircraft. This practice continues today, primarily with bombers, fighter and attack aircraft where weight is a critical consideration, but also with support craft such as reconnaissance aircraft and freighters. 

More recently, there has been a renewed recognition of the potential of bark-derived polyphenols for adhesives as a result of improved understanding of the chemical structure of these materials (, 5), new types of formulations (5), and the fact that tannins are being commercially used in adhesives in South Africa (7), thus serving as a prototype for utilization in other parts of the world. In order to properly assess the current developments in this field, this overview will provide a historical perspective on adhesives based on tannins as well as a summary of the extraction techniques and chemical structures. Finally, areas where additional work could be fruitful will be suggested. 

In the context of a book on adhesives from renewable resources, blood- and casein-based adhesives are worthy of mention because of their great historical importance to the adhesives industry. Caseins are particularly important because they were the first adhesives recognized for forming structurally capable bonds in wood products. They have been used since 1880 and they are still the preferred materials for many types of bonding due to their excellent adhesive properties and ease of cure. Despite their animal origins, these materials are far from plentiful. This makes them quite expensive in terms of wood adhesives, which is the viewpoint of this discussion. The review of the history, nature, manufacturing, and uses of these materials that follows may help to develop a perspective on their future usefulness to the adhesives industry. 

Historically, the reaction of phenol with formaldehyde was of vital importance to the polymer industry, being one of the first totally synthetic commercial polymer resin systems developed. In 1907, Leo H. Baekeland commercialized, under the tradename Bakelite , a range of cured phenol-formaldehyde resins, which were useful in producing heat-resistant molded products . Since this early work, phenol-formaldehyde resins have been used in many applications, including refractory compounds, adhesives, thermal insulation and electrical industries ". ... 

Before the advent of synthetic resin adhesives, semisynthetic cellulosic materials were developed, but when they were first dissolved in solvents and used as an adhesive is not clear from the literature. Historically, the first thermoplastic synthetic adhesive (only partly synthetic) was the cellulose ester cellulose nitrate, often called nitrocellulose, and it is still one of the most important. Later, other esters such as the acetate were developed, as well as certain mixed esters [1, p. 295]. 

Historically, surface treatments to improve adhesion of coatings to plastics consisted of mechanical abrasion, solvent wiping, solvent swell that was followed by acid or caustic etching, flame treatment, or corona surface treatment. Each of these treatments has limitations, thus providing a strong driving force for the development of alternative surface preparation methods. Many of the common methods mentioned are accompanied by safety and environmental risks, increased risk of part damage, and expensive pollution and disposal problems. 

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