TY - JOUR
T1 - Gas foaming of segmented poly(ester amide) films
AU - Lips, P.A.M.
AU - Velthoen, I.W.
AU - Dijkstra, Pieter J.
AU - Wessling, Matthias
AU - Feijen, Jan
PY - 2005
Y1 - 2005
N2 - Biodegradable segmented poly(ester amide)s, based on dimethyl adipate, 1,4-butanediol and N,N¿-1,2-ethanediyl-bis[6-hydroxy-hexanamide], with two distinct melting transitions were gas foamed using carbon dioxide (CO2). Polymer films were saturated with CO2 at 50 bar for 6 h after which the pressure was released. The samples were immersed in octane at the desired temperature after which foaming started immediately. Just above the lower melt transition the polymers retain adequate mechanical properties and dimensional stability, while the chain mobility increased sufficiently to nucleate and expand gas cells during the foaming process. In this way semi-crystalline poly(ester amide)s can be gas foamed below the flow temperature.
Two poly(ester amide)s with 25 mol% (PEA2,5-25) and 50 mol% (PEA2,5-50) of bisamide segment content were foamed at 70 and 105 °C, respectively. The storage modulus (G¿) of both pure polymers at the onset foaming temperature is 50¿60 MPa. Closed-cell foams were obtained with a maximum porosity of not, vert, similar90%. The average pore size of PEA2,5-25 ranges from 77 to 99 ¿m. In contrast, the average pore size of PEA2,5-50 is in between 2 and 4 ¿m and can be increased to 100 ¿m by lowering the CO2 saturation pressure to 20 bar. The porosity of PEA2,5-50 foams using this saturation pressure decreased to 70%
AB - Biodegradable segmented poly(ester amide)s, based on dimethyl adipate, 1,4-butanediol and N,N¿-1,2-ethanediyl-bis[6-hydroxy-hexanamide], with two distinct melting transitions were gas foamed using carbon dioxide (CO2). Polymer films were saturated with CO2 at 50 bar for 6 h after which the pressure was released. The samples were immersed in octane at the desired temperature after which foaming started immediately. Just above the lower melt transition the polymers retain adequate mechanical properties and dimensional stability, while the chain mobility increased sufficiently to nucleate and expand gas cells during the foaming process. In this way semi-crystalline poly(ester amide)s can be gas foamed below the flow temperature.
Two poly(ester amide)s with 25 mol% (PEA2,5-25) and 50 mol% (PEA2,5-50) of bisamide segment content were foamed at 70 and 105 °C, respectively. The storage modulus (G¿) of both pure polymers at the onset foaming temperature is 50¿60 MPa. Closed-cell foams were obtained with a maximum porosity of not, vert, similar90%. The average pore size of PEA2,5-25 ranges from 77 to 99 ¿m. In contrast, the average pore size of PEA2,5-50 is in between 2 and 4 ¿m and can be increased to 100 ¿m by lowering the CO2 saturation pressure to 20 bar. The porosity of PEA2,5-50 foams using this saturation pressure decreased to 70%
KW - METIS-229350
KW - IR-54815
U2 - 10.1016/j.polymer.2005.07.052
DO - 10.1016/j.polymer.2005.07.052
M3 - Article
SN - 0032-3861
VL - 46
SP - 9396
EP - 9403
JO - Polymer
JF - Polymer
IS - 22
ER -