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N-(1-苯乙基)丙烯醯胺[N-(1-Phenylethyl) acrylamide, M1]和 7-丙烯
醯氧-4-甲基香豆素[7-Acryloyl-oxy-4-methyl coumarin,M2]在70℃下，
N,N-二甲基醯胺(DMF)中進行自由基共聚合反應，合成側鏈具有4-甲基香
豆素的共聚合物。由Fineman-Ross法、Kelen-Tudos法、Mayo-Lewis法、
和Y.B.R.法求得兩單體反應性比約為r=0.16、 r=1.23。由單體反應性比
可知在高分子中，可知M2單體反應性較高。由所合成的高分子溶於1,4-二
氧陸圜溶液中，在濃度10∼10M下，以350nm紫外光照射行環丁烷的交聯反
應後，再以25 4nm光源照射時，在本實驗發現除了已知的裂解反應外，同
時有交聯反應的產生，使反應後期達到一個動態平衡。由於採用低濃度的
反應溶液，使光反應僅限高分子內進行，高分子的構造將影響其光反應的
速率。本研究發現高分子組成比(F)值愈小，其交聯速率愈小，裂解速率
愈大。
The copolymer of N-(1-phenylethyl)acrylamide (M1)and 7-
acryloyloxy-4-methyl coumarin (M2), which containsphoto- active
4-methyl coumarin pedant group, was prepared by free radical
copolymerization in DMF at 70C. The monomer react- ivity
ratios (MRR) of M1 and M2 were estimated by the Fineman-Ross,
Kelen-Tudos, Mayo-Lewis,and Y.B.R methods to be about r= 0.16
and r= 1.23.From the MRR values, clearly the reactivity of M2
is higher than M1. The copolymer solution (10∼10M in dioxane)
was first photocrosslinked (350 nm) and then photocleavaged(254
nm) within a Rayonet RPR-100 Photochemical Reactor.The re-
actions were traced by a UV-Visible spectrophotometer, it was
found that when 254 nm was the light source photo- crosslinking
and photocleavage occuredsimultaneously and finally reached to
a dynamic equilibrium. However, only photo -crosslinking could
be observedunder 350 nm light. Beacuse of the very low
concentration, the photoreaction should occurs intramolecularly
and the reaction rate con- stant should be affected by the
composition of the copolymer . Kinetic results showed that the
photocrosslinking rate constant increased with mole fractionof
M2 in the copolymer (F). On the contrary, photocleavage rate
constant decreased with increasing F. Beacuse of the low
concentration solution, the photoreaction rate is affected by
the compositon of the copolymer.the result showed that If the
mole fraction of M2 in the copoly- mer(F) is smaller, the
reaction rate would be smaller in photocrosslinking and larger
in photocleavage.
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