2,6⁃单取代双酚A间苯二甲醛树脂的合成及其在可逆热敏变色复合NiBR膜中的应用

Synthesis of 2,6⁃monosubstituted bisphenol A isophthalaldehyde phenolic resin and its applications in reversible thermochromic composite NiBR film

采用双酚A与低熔点、弱π⁃π堆积作用且活性略高于对苯二甲醛(TPD)的潜在生物质——间苯二甲醛(IPD)为单体,在开放与溶液共缩聚体系中,微波辅助合成数均相对分子质量(M_(n))为1.150×10^(3)g/mol、多分散指数(PDI)为1.004的2,6⁃单取代双酚A间苯二甲醛低聚酚醛树脂,采用核磁氢谱(^(1)H⁃NMR)、核磁碳谱(^(13)C⁃NMR)和傅里叶变换红外光谱(FTIR)表征其结构,以树脂做显色剂制备可逆热敏变色复合镍系顺丁橡胶膜。结果表明,由于IPD的低熔点、弱π⁃π堆积作用,BPA⁃IPD树脂的柔性及部分生成的IPD端COOH,有利于生成潜热较低的低、高温段共结晶相,提升低温段共结晶相的结晶限、变色速度(ΔE/t)以及与1,4⁃高顺式顺丁橡胶(NiBR)的互容性、稳定性;经配方优化的复合膜,在12~37℃的总色差(ΔE),在480~600 nm、600~660 nm可见光区的吸收/散射色差(ΔK S)分别达85左右,20与45左右,ΔE/t达2.14 s^(-1)。

A 2,6⁃monosubstituted bisphenol⁃A(BPA)⁃isophthalaldehyde(IPD)oligomerized phenolic resin with a num⁃ber⁃average molecular weight of 1.150×10^(3)g/mol and a polydispersion index of 1.004 was synthesized through micro⁃wave⁃assisted solution copolycondensation in an open system using BPA and potential biomass IPD as monomers.This potential biomass IPD has a low melting point,a weakπ⁃πstacking interaction,and a slightly higher activity than tere⁃phthalaldehyde(TPD).The structure of the as⁃synthesized phenolic resin was confirmed by ^(1)H⁃NMR,13C⁃NMR,and FTIR.A reversible thermochromic composite Nickel⁃based butadiene rubber(NiBR)film was prepared by using the as⁃synthesized phenolic resin as a color developing agent.The results indicated that the flexibility of BPA⁃IPD and partially generated carboxyl end groups of IPD facilitated to generate low⁃and high⁃temperature eutectic phases with lower latent heat due to a low melting point and a weakπ⁃πstacking interaction of IPD.This improved the crystallization limit in the low temperature eutectic phase and color changing speed of the NiBR film and enhanced its compatibility with 1,4⁃high cis⁃NiBR and stability.The total color difference of the NiBR film was optimized to be around 85 at 12~37℃through a formula.The absorption⁃scattering color depth difference of the NiBR film were approximately 20 and 45 at visible light range of 480~600 and 600~660 nm,respectively,and its color changing speed was 2.14 s^(-1).