| Popis: |
The polymer is used in hundreds of diverse applications and in very large volumes. This chapter provides an understanding of the fundamental chemistries, uses, and values of these materials, as well as provides enough references to permit the interested reader to begin his or her own exploration of the topic. The reasons for the long-term, commercial robustness of phenolic technology include low cost, versatility, heat and flame resistance, durability, strength and stiffness, low toxicity, and ease of processing. It is traditional to divide phenolics into two main categories: novolacs and resoles. This system of classification is consistent with the division of applications as well as the compositions and conditions of resin manufacture. Novolacs are used primarily in the molding industries and electronics applications. Resoles are used primarily as binders for other materials. The chapter discusses the synthesis of phenolic resins. The manufacture of phenol-formaldehyde resins, or any phenolic resin, is a potentially dangerous undertaking both in the laboratory and in the manufacturing facility. There are several levels of danger of which chemists and reactor operators should be well aware. |
