Reactive Compatibilizer Precursors for LDPE/PA6 Blends, 4

Abstract

Summary: The effectiveness of some thermoplastic elastomers grafted with maleic anhydride (MA) or with glycidyl methacrylate (GMA) as compatibilizer precursors (CPs) for blends of low density polyethylene (LDPE) with polyamide‐6 (PA) has been studied. The CPs were produced by grafting different amounts of MA or GMA onto a styrene‐block‐(ethylene‐co‐1‐butene)‐block‐styrene copolymer (SEBS) (KRATON G 1652), either in the melt or in solution. A commercially available SEBS‐g‐MA copolymer with 1.7 wt.‐% MA (KRATON FG 1901X) was also used. The effect of the MA concentration and of other characteristics of the SEBS‐g‐MA CPs was also studied. The specific interactions between the CPs and the blends components were investigated through characterizations of the binary LDPE/CP and PA/CP blends, in the whole composition range. It was demonstrated that the SEBS‐g‐GMA copolymers display poor compatibilizing effectiveness due to cross‐linking resulting from reactions of the epoxy rings of these CPs with both the amine and the carboxyl end groups of PA. On the contrary, the compatibilizing efficiency of the MA‐grafted elastomers, as revealed by the thermal properties and the morphology of the compatibilized blends, was shown to be excellent. The results of this study confirm that the anhydride functional groups possess considerably higher efficiency, for the reactive compatibilization of LDPE/PA blends, than those of the ethylene‐acrylic acid and ethylene‐glycidyl methacrylate copolymers investigated in previous works.SEM micrograph of the 75/25 LD08/PA blend (with 2 phr SEBSMA1).magnified imageSEM micrograph of the 75/25 LD08/PA blend (with 2 phr SEBSMA1).

Interfacial tension of compatibilized blends of LDPE and PA6: the breaking thread method

“…The preparation of the compatibilized blends is described elsewhere [19,21]. The blends were fractured under liquid nitrogen and the surfaces were covered with gold.…”

“…In the previous papers the compatibilizing efficiency of three types of compatibilizer precursors (CP) towards blends of low density polyethylene (LDPE) with PA6 have been studied: (i) poly(ethylene-co-acrylic acid) (Escor 5000, 5001 and 5010, by Exxon) having different concentration of acrylic acid (from 6 to 11 wt%) [19]; (ii) ethyleneglycidylmethacrylate copolymer (Lotader GMA AX8840) [20]; (iii) triblock copolymer with polystyrene end blocks and a rubbery poly(ethylene -butylene mid block (SEBS) (Kraton G 1652) and SEBS-g-MA (Kraton FG 1901X) with 2 wt% maleic anhydride [21]. The effectiveness of the CP has been evaluated by an investigation of the thermal properties and the morphology of binary (LDPE/CP and PA6/CP) and ternary (LDPE/PA6/CP) blends, as well as by solvent fractionation experiments.…”

Thermo‐oxidative decomposition kinetics of elastomeric composites based on styrene‐(ethylene‐butylene)‐styrene triblock copolymer and organomontmorillonite

“…No much effect was found on the enhanced interaction between the maleic anhydride group on SEBS and hydroxide group on the OMMT. Perhaps the overlapping aromatic overtone signals on PS blocks with the carbonyl group on maleic anhydride resulted in an insignificant maleated compatibilizer contribution 3, 37…”

Efeito da Montmorilonita Organifílica na Compatibilização e nas Propriedades Morfológicas, Mecânicas e Térmicas de Blendas de PA6/ PEBD

“…propriedades térmicas, mecânicas e morfológicas das blendas [17][18][19][20][21] . Embora o uso de compatibilizantes tenha mostrado eficiência na obtenção de propriedades interessantes nestes sistemas, a abordagem associada ao uso de nanocargas é mais recente e promissora.…”