Stress–strain behavior of low‐density polyethylene/poly(methyl methacrylate) blends with modulated interfaces with a hydrogenated polybutadiene‐block‐poly(methyl methacrylate) diblock copolymer

Abstract

The stress-strain diagrams and ultimate tensile properties of uncompatibilized and compatibilized hydrogenated polybutadiene-block-poly(methyl methacrylate) (HPB-b-PMMA) blends with 20 wt % poly(methyl methacrylate) (PMMA) droplets dispersed in a low-density polyethylene (LDPE) matrix were studied. The HPB-b-PMMA pure diblock copolymer was prepared via controlled living anionic polymerization. Four copolymers, in terms of the molecular weights of the hydrogenated polybutadiene (HPB) and PMMA sequences (22,000 -12,000, 63,300 -31,700, 49,500 -53,500, and 27,700 -67,800), were used. We demonstrated with the stress-strain diagrams, in combination with scanning electron microscopy observations of deformed specimens, that the interfacial adhesion had a predominant role in determining the mechanism and extent of blend deformation. The debonding of PMMA particles from the LDPE matrix was clearly observed in the compatibilized blends in which the copolymer was not efficiently located at the interface. The best HPB-b-PMMA copolymer, resulting in the maximum improvement of the tensile properties of the compatibilized blend, had a PMMA sequence that was approximately half that of the HPB block. Because of the much higher interactions encountered in the PMMA phase in comparison with those in HPB (LDPE), a shorter sequence of PMMA (with respect to HPB but longer than the critical molecular weight for entanglement) was sufficient to favor a quantitative location of the copolymer at the LDPE/PMMA interface.

Plasticized PVC graphene nanocomposites: Morphology, mechanical, and dynamic mechanical properties

“…However at higher loading, filler–filler interactions are dominated leading to high stress concentration in the PVC matrix due to poor dispersion. This results in decreased elongation at break .…”

On the phase affinity of multi-walled carbon nanotubes in PMMA:LDPE immiscible polymer blends

“…In contrast to electrical conductivity, rheological percolation in immiscible polymer blends is only achieved if the percolated polymer constitutes the major phase or, at least, significantly contributes to the bulk rheology of the blend. A well-known example of the above mentioned improved performance derived from immiscible polymer blends would be the increased toughness of brittle matrices with rubbers or poly(olefin)s or, inversely, the promotion of enhanced tensile strength in elastomers filled with a brittle polymer [12].…”

“…These polymers, which have traditionally been used as commodity plastics, have lately found application in the manufacture of products with high added value [12]. Very few studies have been reported on PMMA/PE blends filled with carbon-based conductive particles (e.g.…”

Synthesis and utility of ethylene (meth)acrylate copolymers prepared by a tandem ring‐opening polymerization hydrogenation strategy

“…[10][11][12]20 In this work, a PE/PMMA blend with PMMA as the dispersed phase was targeted in an effort to improve the blend properties by using a "random" copolymer compatibilizer. In a binary blend of PE/PMMA (80/20), clear macrophase separation was observed.…”

“…Interestingly, with the use of PEMMA-3 copolymer that has the lowest MMA mole percent, the elastic modulus of the compatibilized blend was nearly a factor of 2 larger than the binary blend (up to 170 MPa) while still retaining high elongation-at-break values (e.g., 780%) ( Table 2). 20 Mechanical Properties of PEBA-Based Elastomers Mechanical properties of the PEBA samples were also evaluated by uniaxial extension experiments. Figure 5a shows representative tensile tests for PEBA-12.5 and PEBA-6.5.…”