加速环氧树脂生物降解的溶胀氧化协同预处理机理OA

Epoxy resin,which has been widely and extensively applied in the field of electrical insulation because of its outstanding structural stability,encounters significant hurdles in the recycling process.This is primarily attributed to its highly cross-linked network structure.Traditional physical and chemical pretreatment methods often involve harsh conditions,high costs,or environmental risks.In order to accelerate the degradation,this paper proposes a synergistic pretreatment strategy.It makes use of Dipropyleneglycol dimethyl ether(DMM),a green solvent,and low-concentration KMnO4 to disrupt the structural integrity of the epoxy resin under relatively mild operating conditions. A total of 45 experimental groups were meticulously and systematically designed to assess the impacts of various parameters.The experimental parameters were set as follows:reaction temperature 85～99℃,duration 30～90 min;KMnO4 solutions at 0.1 and 0.5 mol/L;and treatment modes—DMM and KMnO4 were applied either individually or in combination.Thermogravimetric analysis(TGA),differential scanning calorimetry(DSC),Fourier-transform infrared spectroscopy(FTIR),dynamic mechanical analysis(DMA),and scanning electron microscopy(SEM)were utilized to evaluate thermal stability,cross-linking density,mechanical properties,and morphological changes.Meanwhile,this paper explores the action mechanisms of different treatment methods. According to the experimental results,this pretreatment method significantly reduces the physical stability and chemical cross-linking degree of the epoxy resin.At the same time this paper proposes that the mechanism of action of DMM is to penetrate into the structure of the epoxy resin through swelling,making the original system loose.At the same time,it forms a new system with the epoxy resin through hydrogen bonding,thereby reducing its physical stability.Potassium permanganate will form different oxidation products under different reaction conditions,and specific reaction pathways are proposed in this paper.When applied to Aspergillus niger mediated biodegradation,pretreated samples exhibited accelerated degradation.After 30 days,the Tg of combined-pretreated samples decreased to 40～45℃,compared to 90～95℃for untreated controls.Pretreatment makes the surface of the sample rough and rich in hydroxyl groups,which enhances the attachment and reproduction of Aspergillus niger.