基于淀粉液化改性氨基树脂的合成及表征

以淀粉经α-淀粉酶液化得到的产物(AS)、甲醛(F)、三聚氰胺(M)为主要原料,在弱碱性条件下合成液化淀粉改性氨基树脂(ASMF)。对ASMF树脂的合成工艺、性能及分子结构进行探讨,并对淀粉液化产物进行SEM及FT-IR分析。结果表明:ASMF树脂理想的合成工艺为pH值9.0、合成反应温度区间为88~90℃、甲醛与三聚氰胺摩尔比为2.0:1,淀粉液化产物与三聚氰胺的质量比为0.4:1。在此条件下,ASMF树脂的胶合强度可达1.52 MPa,贮存期可达27 d(25℃)。SEM结果表明:糊化后的淀粉,结构比较疏松,易受到α-淀粉酶的攻击,随着时间的延长,颗粒被破裂成大小不一的碎片;FT-IR结果表明:淀粉液化后N-OKI值下降,结晶度降低;ASMF树脂分子结构主要以亚甲基键和亚甲基醚键相连接。

Synthesis and Characterization of Amyloid-modified Amino Resins Based on Starch Liquefaction

The production of starch by alpha-amylase liquefaction(AS),formaldehyde(F),and melamine(M)were used as the main raw materials to synthesize liquefied starch modified amino resin(ASMF)under weak alkaline conditions.The synthetic process,properties and molecular structure of ASMF resin were discussed,and the liquefied products of starch were analyzed by SEM and FT-IR.The results showed that the ideal synthetic process of ASMF resin is pH 9.0,the synthesis reaction temperature range is 88~90℃,the molar ratio of formaldehyde to melamine is 2.0:1,and the mass ratio of starch liquefaction product to melamine is 0.4:1.Under these conditions,the bonding strength of ASMF resin can reach 1.52 MPa,and the storage period can reach 27 d(25℃).SEM results showed that the gelatinized starch had a loose structure and was susceptible to attack byα-amylase.As time passed,the granules were broken into fragments of different sizes.FT-IR results showed that N-OKI values after starch liquefaction as the crystallinity decreases,the molecular structure of the ASMF resin is mainly connected by methylene bonds and methylene ether bonds.