Durability degradation reactions

Phenol-formaldehyde type polymers had been the only exterior-durable adhesives for wood bonding, until the recent limited use of isocyanates. Both systems are petrochemical-based. Several researchers substituted carbohydrates for part of phenolic adhesives (1-4) > producing solid, fusible novolak resins. Recently, reaction of carbohydrate acid-degradation products with phenol and formaldehyde has produced liquid resols (5). Gibbons and Wondolowski (6,7) replaced a considerable amount of phenol with carbohydrate and urea to pro-... 

The combustion of CCI2F2 in oxygen at 500 °C was studied in the presence of more than 20 different catalysts. The combustion products are CO, CO2, and F2. Because of fluorine s tremendous reactivity, metallic and silicon-based catalysts degraded rapidly. The most durable catalyst was found to be BPO4 however, it also did not have a satisfactory life because of fluorine reaction with boron [103],... 

An alternative tactic to deal with the problem of polymer wastes is to make polymers degradable. The difficulty with this approach is that in making synthetic polymers degradable one of the greatest assets of these materials, namely their durability, may be eliminated. There is also the possibility that degradation may give rise to reaction products that may themselves cause environmental problems. For example toxic wastes from degrading polymers have caused problems of water pollution in the vicinity of landfills. 

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