交联共聚高强淀粉胶黏剂的制备与性能

Preparation, characterization and properties of high-strength starch-based adhesive by cross-linking and copolymerization

摘要:

以天然玉米淀粉（St）为原料，衣康酸（IA）为接枝单体，过硫酸铵（APS）和NaHSO3为氧化还原体系，聚乙烯亚胺（PEI）和硼砂（Borax）为复合交联剂，制备交联共聚高强淀粉胶黏剂（OSt-IA-PEI/Borax）。采用FTIR、SEM和TGA对材料进行表征和测试，基于黏度和剪切强度测定、耐水性测试，考察APS和IA用量、m(NaHSO3)∶m(APS)、m(PEI)∶m(Borax)、复合交联剂PEI-Borax用量对淀粉胶黏剂性能的影响。结果表明，经IA接枝共聚后的OSt-IA-PEI/Borax胶膜表面平整、均一，经交联-共聚改性后热稳定性明显提升；采用复合交联剂PEI-Borax交联并IA接枝共聚改性淀粉可以有效提升其粘结强度（59.0%）和耐水性能（75.0%）。OSt-IA-PEI/Borax最佳合成工艺条件为：APS和IA用量为分别为淀粉质量的1.2%和10%，m(NaHSO3)∶m(APS)＝2∶3，复合交联剂PEI-Borax用量淀粉质量的3.0%，m(PEI)∶m(Borax)＝3∶1，此条件制备的胶黏剂剪切强度可达8.92 MPa，在60±3 ℃热水中的耐水时间为3.5 h。

Abstract:

A high-strength crosslinked starch adhesive (OSt-IA-PEI/Borax) was synthesized using natural corn starch (St) as the base material, itaconic acid (IA) as the grafting monomer, and an ammonium persulfate (APS) and NaHSO3 redox system. Polyethyleneimine (PEI) and borax were employed as composite crosslinking agents. The material was characterized by FTIR, SEM, and TGA, while viscosity, shear strength, and water resistance tests were conducted to evaluate the effects of APS and IA concentrations, the m(NaHSO3)∶m(APS), m(PEI)∶m(Borax), and the PEI-Borax crosslinking agent dosage on the adhesive"s properties. The results demonstrated that the graft copolymerization of IA produced a smooth and uniform adhesive film, and the crosslinking copolymerization significantly enhanced the thermal stability of the modified starch adhesive. The PEI-Borax composite crosslinking, along with IA grafting, effectively improved bonding strength by 59.0% and water resistance by 75.0%. The optimal synthesis conditions for OSt-IA-PEI/Borax were found to be 1.2% APS and 10% IA based on starch mass, NaHSO3-to-APS ratio of 2:3, and a PEI-Borax dosage of 3.0% with a mass ratio of PEI to Borax at 3:1. Under these conditions, the adhesive achieved a shear strength of 8.92 MPa and a water resistance duration of 3.5 hours at 60 ± 3 °C.