Phenolic resins history

Phenolic resins some chemistry, technology, and history... 

Phenolic resins were the first totally synthetic plastics invented. They were commercialized by 1910 [I]. Their history begins before the development of the structural theory of chemistry and even before Kekule had his famous dreams of snakes biting their tails. It commences with Gerhardt s 1853 observations of insoluble resin formation while dehydrating sodium salicylate [2]. These were followed by similar reports on the behavior of salicylic acid derivatives under a variety of reaction conditions by Schroder et al. (1869), Baeyer (1872), Velden (1877), Doebner (1896 and 1898), Speyer (1897) and Baekeland (1909-1912) [3-17]. Many of these early reports appear to involve the formation of phenolic polyesters rather than the phenol-aldehyde resins that we think of today. For... 

Much interest has centred on the branch of cyclophanes known as calixarenes. They are polyphenol systems that can act as hosts in the formation of inclusion compounds, where a small guest molecule resides completely in a cavity within a single host they are cone-shaped cavitands . Several accounts have appeared of their history. The discovery by Baeyer of a formaldehyde/phenol resin led to Bakelite and to the work of A. Zincke and E. Ziegler, who gave to the first oligomer a tetrameric structure of a calix[4]arene. Later syntheses by Gutsche (1978) led to calixarenes with 4, 6 or 8 phenol residues.107-109... 

History. Phenolic resin is a condensation-type high polymer formed by the reaction of phenols and aldehydes. In 1910, research and industrialization of this resin were promoted in the U.S. by L. Baekeland (1). In Japan and Europe research on this resin was also started at about the same time. 

Phenolic foams were first used in Germany in the early 1940 s to replace Balsa wood for use in aircraft (2). Notwithstanding the fact that both phenolic resin and phenolic foam itself have long histories, newer applications have imdergone slow development. Quite recently, however, the heat resistance as well as fire resistance qualities of this foam have focused attention to its wide uses. 

Some polymers are easier to foam than others. Indeed, it was not until methods were found to circumvent the inclusion of cells in the early history of the phenol formaldehyde polymer that it gained any commercial significance. The development of foamed phenolic resins only became important much later when a specific need arose to produce rigid foam with reduced flammability. This consideration also led to the development of polyisocya-nurate foams and carbodiimide foams. On the other hand, the polypropylene family of polymers, although having a tonnage far exceeding that of phenol formaldehyde resins, is... 

When an applications engineer thinks of typical reinforcing fibers for plastics the first thing that comes to mind will be glass fibers. In the actual history of this technology, however, the use of organic fibers began several decades earlier with the use of natural cellulose fibers to reinforce phenolic resins (Fig. 37). 

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