Formulation and raw material selection

Safe preparation of polyester resins from polyfunctional monomers (Fjj 2) without gelation requires careful optimization of average functionality and calculation of the degree of polymerization at the gel point (Pg j). Wallace Carother and PJ. Floryhave made significant contributions in this area however, a detailed discussion is outside the scope of this book. 

A wide range of raw material is available to design polyesters with a broad spectrum of properties. In addition to the polyols listed in the section on alkyd resins (Section 2.3), other specialty diols are also used in polyester synthesis. Some important polyols are listed in Table 2.4. 

Various polybasic acids are used in polyester synthesis, including aromatic acids as well as aliphatic acids. Some important acids used in polyester synthesis and their primary characteristics are shown in Table 2.5. 

In addition to polybasic acids, some monobasic acids including lower MW synthetic branched fatty acids and monobasic aromatic acids are also used for controlling functionality and MW of polyesters. 

Neopentyl glycol 2 Hardness, heat resistance, impact resistance, chemical resistance 

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