Silicone aliphatic polyesteramides

In another study, lipase-catalyzed silicone polyesteramides in the bulk at 70°C under reduced pressure (10-20 mmHg) have been reported [22]. Novozym-435 was used as the enzyme under mild reaction conditions to perform the polycondensation reaction using various feed mole ratios of diethyl adipate (DBA), 1,8-octanediol (OD), and a,w-(diaminopropyl) polydimethylsiloxane (Si-NH ). The authors also synthesized poly(octamethyleneadipate), POA, and poly(a,w-(diaminopropyl) polydimethyl siloxane adipa-mide), PSiAA, using the same enzyme, and compared their properties with those of silicone polyesteramides. 

The relative amounts of amide and ester units in the polymer chain strongly influenced the physical properties of the polyesteramides. Presence of high content of DBA-O A units resulted in hard solid materials containing a well-developed high melting POA-type crystal phase. Indeed, a melting temperature was observed at around 67°C, which depended on the copolymer composition. When DEA-SiAA units were the major component, the material exhibited a sticky appearance. 

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Scheme 2.3 Lipase (Novozym-435)-catalyzed synthesis of silicone fluorinated aliphatic polyesteramides (SFAPEAs) by transesterification and amidation of a,0)-aminopropyl terminated poly(dimethylsiloxane) (APDMS) and 3,3,4,4,5,5,6,6-octafluoro 1,8-octanediol (OFOD) with diethyl adipate (DBA), respectively, at temperatures in the range of 70°C to 90°C in the bulk [23], Reproduced with permission (Copyright 2010, Elsevier).

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