Effect of the Monomer Ratio on the Strengthening of Polymer Phase Boundaries by Random Copolymers

Abstract

The fracture toughness Gc of an interface between the immiscible homopolymers polystyrene (PS) and poly(2-vinylpyridine) (PVP) reinforced with random copolymers, dPSf-r-

Quantifying and Controlling the Composition and ‘Randomness’ Distributions of Random Copolymers

“…However, there exist conflicting results regarding the utility of random copolymers as interfacial modifiers. [11,12,13,25] These results include studies on mixtures of polystyrene (PS) and poly(methyl methacrylate) (PMMA) with random copolymers of PS and PMMA as compatibilizer which show that the random copolymer does not improve the strength of the biphasic interface as well as a block copolymer. [12,13] Alternatively, if the same experiment is completed on mixtures of PS and poly(2-vinyl pyridine) (P2VP) with a PS/P2VP random copolymer, the random copolymer substantially improves the interfacial strength between the two homopolymers [11,25] Additionally, seminal work by Fayt et al [32 -36] showed that addition of tapered (which can also be thought of as a type of random) copolymers of PS and polyethylene(PE) to a blend of PS and PE improved the elongation and ultimate strength of that blend more than the addition of a similar diblock copolymer.…”

The reinforcement of polystyrene and poly(methyl methacrylate) interfaces using alternating copolymers

“…In these experiments, the addition of a compositionally symmetric P(S-ran-2VP) resulted in the greatest increase in G c of the interface and forward elastic recoil spectroscopy showed that this copolymer provided a symmetric interface [15]. In a separate study, investigation of the fractured ADCB beams using forward recoil spectroscopy determined that in a system with multiple interfaces fracture always occurs at the interface with the smallest w i [16].…”

“…The wafers were washed three times, using alternate washings of acetone and toluene to remove any organic material from the surface. The wafers were then placed in an ultra-violet ozone oven for 15 …”

“…The effectiveness of random copolymers to reinforce polymers interfaces has also been widely investigated [11,12,15,21,22,[33][34][35][36][37][38] and was found to be dependent on the monomer composition [22]. In the case of PðS f -ran-MMA 12f Þ; where f is the monomer composition, the compositionally asymmetric P(S 0.7 -ran-MMA) displayed the greatest reinforcement of the PS/PMMA interface out of a range of P(S-ran-MMA) compositions studied [21].…”

ToF‐SIMS study of the surface morphology of blends of polystyrene and poly(N‐vinyl‐2‐pyrrolidone) compatibilized by poly(styrene‐co‐4‐vinylphenol)

“…16,17 In practice, random copolymers could be good compatibilizers that are relatively easy to synthesize at low cost. Recently, Dai et al investigated the immiscible blend of polystyrene (PS) and poly(2-vinylpyridine) (PVPy) compatibilized by a random copolymer of deuterated PS and PVPy 5 and a random copolymer of poly(styrene-co-2-vinylpyridine) (STVPh). 18 They found that the long, random copolymers could be remarkably effective in reinforcing the immiscible polymer blend interfaces.…”