Study On The Compatibility And The Mechanical Performance Of Waste Household Appliances HIPS And ABS Blend System

High-impact polystyrene and acrylonitrile-butadiene-styrene have the excellent comprehensive performance, which are the most currently used polymers in the fields of electrical and electronical equipments. Recycled ABS and HIPS are similar in appearance and density, which makes separation more difficult. It affects the recycling of HIPS and ABS, leading to the resource waste. Secongdly, due to the existence of polar nitrile group in R-ABS, delamination may occur during the simple mixing process of HIPS and ABS on account of poor compatability, rendering compositis more brittle. Meanwhile, the degradation process in R-HIPS and R-ABS copolymers tempted by light, heat and oxygen, induced a deterioration of the mechanical properties and long-term stability remarkble deterioration. These conditions limited the reuse of R-HIPS and R-ABS.In this paper, degrees of aging of R-HIPS and R-ABS under natural condition were studied separately; maleic anhydride grafted styrene-ethylene-butylenes-styrene block copolymer was introduced as compatilizer and effect of its dosage on the compatibility of R-HIPS and R-ABS blends were studied; SEBS-g-MAH and oxazoline functionalized recycled ABS as the composite reactant compatibilizer were added to further enhance the interfacial consistency. the comprehensive mechanical properties of R-HIPS and R-ABS blend could be improved by improving the compatibility among three phase interfaces, rubber phase PB and matrix phase PS of R-HIPS, rubber phase PB and matrix phase SAN of R-ABS, and matrix phase PS and SAN of R-HIPS and R-ABS blend, achieving success recycling of R-HIPS and R-ABS.From the above, we could draw the following conclusions:(1) The degradation mechanism of R-HIPS and R-ABS was characterized by using gel permeation chromatography, fourier transform infrared spectroscopy, nuclear magnetic resonance, gel content, grafting rate and mechanical properties in this paper. The results indicated that carbonyl and carboxyl groups generated throughout the aging process of R-HIPS abd R-ABS. Molecular chains could be inferred to be broken in PB-g-PS and PB-g-SAN, which linked the rubber phase and matrix phase inside R-HIPS and R-ABS individually. This could cause the decreation of molecular weight, phase separation and incompatability between PB phase and PS phase in R-HIPS and PB phase and SAN phase in R-ABS.(2) The compatibility mechanism of R-HIPS and R-ABS was characterized by using differential scanning calorimetry, dynamic mechanical analyzer, scanning electron microscope and mechanical properties in this paper. The results proved that the compatibility of R-HIPS/R-ABS blend was better than HIPS/ABS blend, which was owing to enhanced interfacial addhension in consequence of the intermolecular forces between polar groups(carbonyl, carboxyl, nitrile groups). However, the interfacial bond between rubber phase and matrix phase of R-HIPS and R-ABS, and the compatibility of R-HIPS and R-ABS blend were unfortunate, leading to the unsatisfying mechanical properties of R-HIPS and R-ABS blend.(3) Through mechanical properties, FTIR, DMA, DSC, SEM, rheological properties and thermogravimetric analysis test, the influences of SEBS-g-MAH on R-HIPS and R-ABS blend were studied. Results showed that the bonding strength of three phase interfaces were all strengthend by SEBS-g-MAH's advancement in intermolecular forces, thus, compatibility was perfected. Dipole moment force among maleic anhydride and carbonylor carboxyl group exists in R-HIPS. Oxidized rubber was linked to matrix with SEBS-g-MAH, which strenthend the compatibility between PB and PS. Additionally, R-HIPS was toughened by SEBS. In R-ABS, dipole moment force could be confirmed both between maleic anhydride and carbonyl or carboxyl group, and maleic anhydride and nitril group. Intermolecular force between polar molecules promoted not only the compatibility between R-HIPS and R-ABS but also the compatibility between SAN and matrix PS phase of R-HIPS and R-ABS blend. When the SEBS-g-MAH was added as 15 wt%, the impact strength of R-HIPS/R-ABS/SEBS-g-MAH blend improved from 2kJ/m2 to 7kJ/m2.(4) Through mechanical properties, FTIR, DMA, DSC and SEM test, the influences of R-ABSm on R-HIPS/R-ABS /SEBS-g-MAH blends were studied. The results showed that when the ratio of R-HIPS/R-ABS/SEBS-g-MAH was 7/3/1.5(mass ratio), adding the 4%(mass fraction) R-ABSm, the impact strength of R-HIPS/R-ABS/SEBS-g-MAH blends improved from 2kJ/m2 to 9kJ/m2. It was proved that the carboxyl group of R-ABS the anhydride carbonyl groups of SEBS-g-MAH reacted with the oxazoline groups of R-ABSm separatedly, which boosted the interfacial bonding strength of PB and PS phases in R-ABS and PS and SAN phases in R-HIPS and R-ABS blend. In the meanwhile, decreased rubber content in deterioration could be complemented though chemical link.