臺灣博碩士論文加值系統

由含二酸及二異氰酸酯(-NCO)官能基與次乙亞胺(Aziridine)來合成
兩系列含甲醯次乙亞胺官能基的架橋劑,其結構鑑定可由1H-NMR, 13C-NMR
及IR光譜確定。並且示範此架橋劑與羧酸的開環反應,以說明其對羧酸基
的反應性。 以不同比例之架橋劑加入水性PU中,架橋劑可以穩定的存
在鹼性條件下,但在乾燥過程中PH值降低,將會與水性PU分子側鍊上羧酸基
在常溫下形成開環架橋反應。測量乾膜的膠含量、接觸角、吸水性、吸乙
醇性以及抗張強度、動態機械熱分析(DMTA)等機械性質,證明交聯密度的
增加對機械性質的改善。並且以環氧樹脂配合其中一種架橋劑,先後加入
水性PU中,分別與水性PU的胺基及羧酸基反應,以達到雙重架橋的效果。

Two series of acylaziridinyl compounds were synthesized
from the reactions of aziridine with di-acyl chloride and
polyisocyanates,respectively. These prepared di-function
aziridinyl compounds were identified
by nmr and ir spectroscopies. A ring opening reaction between an
aziridinyl compound with acetic acid were demonstrated. These
di-aziridinyl compounds would react with carboxylic groups
ofaqueous-based PU and function as a PU cross-linker. The curing
reactionof these curing agents took place at ambient temperature
under an acidicenvironment, however, they were stable at an
alkaline conditions. Thecuring behaviors of these curing agents
toward aqueous-based PU wereevaluated by the measruements of gel
content, contact angle, water- oralcohol-uptake, tensile
strength and elongation of PU films. Furthermore,epoxy resins
were applied as a second curing agent for aqueous-based
PUdispersions. The thermal properties of these dual-curing PU
system werealso monitored by thermo-grimetric and dynamic
mechanical analyses.