Improvement of the mechanical properties of an HDPE/PS blend by compatibilization and incorporation of CaCO₃

Abstract

Ecole des Mines d'AlI5s 6 auenue de CZaui&es, 30319 Alks C e h , France 2M&riaux a Flnalitks S@a%ues (MFS) UniVersW de Toulon et du Var BP 132,8395 7 La Gar& Cedex, fianceGenerally, recycled polymer blends exhibit solid dispersion-like morphology with poor mechanical properties. The aim of this work was to enhance the mechanical properties of a HDPE/PS (75/25) blend, in particular the stiffness and the impact strength. In order to improve the stiffness, CaCO, filler was incorporated. It was shown that PS and CaCO, were separately dispersed with poor adhesion to the HDPE matrix. The incorporation of CaCO, significantly enhanced the stiffness but lowers the impact resistance. Elastomer copolymers were incorporated in order to compensate for the embrittlement caused by the CaCO, filler. Depending on their chemical structure, either grafted with a reactive function or ungrafted, the elastomers acted differently at the interfaces of the HDPE/PS/CaCO, system. SEBS acts exclusively at the HDPE-PS interface whereas SEBSgMA acts at both the 650 POLYMER ENGINEERING AND SCIENCE, MARCH 2003, Val. 43, No. 3 Improvement of Mechanical Properties of an HDPE/PS Blend Flg. 2. SEM micrographs [X4000] of cryogenicfiacture surfmes: 24) HDPE/ CaC03 (80/20), 2b) HDPE/CaC03 (80/20) with 4% SEBS, 2c) HDPE/CaCO, (80/20) with 4% SEBSgMA.

Investigation of compatibilization effects of SEBS-g-MA on polystyrene/polyethylene blend with a novel separation method in melted state

“…2/a-e), while from 2 vol% of compatibilizer the fracture path passed through the PS domains (Fig 2/f-i), because of the reaction of the components. In our study the morphology developed at different SEBS-g-MA contents show good agreement with the results of Sahnoune et al [72].…”

“…Some research mentioned styrene-butadiene copolymer (SB) [53] and styrene/butadiene/styrene block copolymer (SBS) [52] as a potential additive for compatibilizing PS and PE with each other, in other papers the effectiveness of polyether copolymer (PEC) [54], hydrogenated butadiene-polystyrene copolymers (SEB) [55] and ethylene/styrene interpolymers [47] were also investigated. However, the most commonly used compatibilizer for improving the miscibility of PS and PE is styrene/ethylene/butylene/styrene block copolymer (SEBS) and its maleic anhydride grafted type (SEBS-g-MA), with which adhesion can be improved between the phases to prepare blends with better toughness [35,44,45,[56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73].…”

“…Previously Sahnoune et al [72] and Ha et al [73] compared the effectiveness of SEBS and SEBS-g-MA in PS/HDPE blends, where both copolymers showed a good compatibilizing effect. Sahnoune et al [72] found that PS and HDPE were immiscible with each other in a 75/25 HDPE/PS blend, where the fracture path spread in the boundary of PS and HDPE, due to the poor interfacial adhesion between the phases.…”

“…Sahnoune et al [72] found that PS and HDPE were immiscible with each other in a 75/25 HDPE/PS blend, where the fracture path spread in the boundary of PS and HDPE, due to the poor interfacial adhesion between the phases. When SEBS or SEBS-g-MA was added to the HDPE/PS blends, a significant reduction was detected in the size of dispersed PS.…”

Toughness Improvement in Ternary HDPE/PS/PET Polymer Blends with Compatibilizer

“…It would be also important to know the effects of the prior homogenisation on morphology, tensile and impact properties of blends. In the first step, styrene/ethylene-butylene/styrene copolymer grafted with maleic anhydride (SEBS-g-MA), which additive is recommended by previous studies [15][16][17], was added to the ternary 70/15/15 wt% HDPE/PS/PET blends in order to improve the impact strength and the elongation at break. Another additive polypropylene grafted with maleic anhydride (PP-g-MA), which is not a recommended additive, was also added to the blends in order to investigate the potential negative effects of an improperly selected additive on tensile and impact properties of blends.…”