Hexamethylene carbonate diol

Table 11.1.3. Compounds identified in the pyrogram of a poly(hexamethylene carbonate) diol sample with M = 860 as shown in Figure 11.1.2.

Common SS include polyethers, polyesters and polyalkyl glycols with glass transition temperatures in the range of -70°to -30°C. Commonly used macrodiols in the PUs synthesis are polyalkyl-diols, such as polyisobutylene diol [70], polybutadiene (PBU) [20, 71], or oligo-butadiene diols [72] as well as hydrogenated polybutadiene diol [20] polyether diols polytetrahydrofuran (PTHF or PTMO) [50-52], polyethylene glycol (PEG) or (PEO) [73], polypropyleneoxide (PPO) [73] or mixed blocks of them PEO-PPO-PEO [74] and PPO-THF [54] polyester diols poly(ethylene adipate) (PEA) [4,20], poly(butylene adipate) (PBA) [20, 73], and latterly polycaprolactone diol (PCL or PCD) [75], polyalkylcarbonate polyol [20] or mixed blocks of them, for example poly(carbonate-co-ester)diol [76], poly(hexamethylene-carbonate)diol [77], as well as poly(hexamethylene-carbonate-co-caprolactone)diol [78] and a mixed block copolymer of polyether and polyester blocks PCL-b-PTHF-b-PCL [79]. Examples schemes of macrodiols are shown in Eig. 1.9. 

Fig. 6.2 Composite plot of different homologous series illustrating odd-even effect. Plot of melting temperature against number of carbon atoms, (a) Aliphatic poly(esters) based on decamethylene glycol number of carbon atoms in dibasic acid, (b) Aromatic poly(esters) based on terephthalic acid number of carbon atoms in diol. (c) Aliphatic poly(amides) based on hexamethylene diamine number of carbon atoms in diacid, (d) Polyfurethanes).

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