A. Laschewsky et E. Rekai, Photochemical modification of the lower critical solution temperature of cinnamoylated poly(N-2-hydroxypropylmethacrylamide) in water, MACRO RAPID, 21(13), 2000, pp. 937-940
Partial modification of the nonionic polymer poly(N-2-hydroxy-propylmethacr
ylamide) by cinnamate produces stimuli-responsive copolymers. The hydrophob
ic character of the cinnamate chromophore induces not only a lower critical
solution temperature (LCST) in water, but renders additionally the polymer
s photoresponsive. For moderate cinnamate contents of 9 mol-%, the photoiso
merization of the trans-cinnamate to cis-cinnamate groups allows to switch
the LCST by irradiation, whereas for higher cinnamate contents of 21 mol-%,
irradiation leads to intra- and intermolecular photocrosslinking.