Enzymatic degradation of aliphatic polyesters copolymerized with various diamines

Abstract

Poly(hexamethy1ene adipate) copolymers with 1040 mol-% (in feed) of aliphatic diamines of various methylene chain lengths were prepared by melt polycondensation. hi vitro degradation was performed in buffer solution at 37 'C with a lipase and was evaluated by weight loss of the films. The weight loss increased greatly by the copolynieriration and showed a maximum at 10 mol-'% of comonomer content. Degradation also increased in a zigzag fashion with decreasing number of methylene chains in the diamine comonomers. Both effects on the enzymatic degradation are discussed.

Copolyesteramides, 10. Enzymatic degradation of 6-iminohexanoyl/12-oxydodecanoyl copolyesteramides

“…Because of the breakages the gravimetric data are incomplete, but those specimens recovered intact (including the N6 and the f series films) showed weight losses of between 5 and 11%, averaging about 2,6 g N m -2 of film surface with no obvious species correlation. These values are somewhat larger than have been reported for other copolyesteramides of similar weight-% ester group content 28,31,33) , but certain of the lat- In m-cresol (c = 0,5 g/100 mL) at 30 8C.…”

“…There are fewer comparative studies with polyamides, but it is clear that the linear aliphatic members (nylons) are considerably longer-lived in physiological environments (although eventual disintegration occurs after lengthy in vivo implantation) 2,6,9,10,[21][22][23][24] and that chemical modification would be needed to encourage shorter-term breakdown. The combination of both types of characteristic groups, as polyesteramides, has therefore been envisaged as a means of affording wider ranges, and hence more specific choices, of biodegradation behaviour [11][12][13][14][25][26][27][28][29][30][31][32][33] . Moreover, the mechanical and thermal properties of polyesteramides are open to wide variation by structural choice 1,[34][35][36][37] so as to make potentially available materials combining desired physical character with the chemical response required for particular biotic conditions.…”

Pretreatment of Proteinic and Synthetic Fibres Prior to Dyeing

“…The water contact angle is found to decrease from 75.8º to about 52º. As the contact angle decreases, the wettability increases and consequently the dyeability is improved (50)(51)(52)(53)(54)(55)(56) .…”

Analytical Methods for Monitoring Biodegradation Processes of Environmentally Degradable Polymers

“…Degradability of PCL fi bers was monitored by dissolved organic carbon ( DOC ) formation and weight loss. Similar systems with lipases have been used for studying the hydrolysis of broad ranges of aliphatic polyesters [25 -30] , copolyesters with aromatic segments [26, 31 -33] , and copolyesteramides [34,35] . Other enzymes such as α -chymotrypsin and α -trypsin have also been applied for these polymers [36,37] .…”