Enthalpic effects on interfacial adhesion of immiscible polymers compatibilized with block copolymers

Adedeji, Adeyinka; Jamieson, A. M.

doi:10.1016/0032-3861(93)90246-7

Cited by 21 publications

(9 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This characteristic behavior is not, however, observed with some of the RBC/hS15 blends seen in Figure , which reveal that hS15 (bright) is excluded from the RBC (dark) matrix in narrow channel structures that do not represent minimization of S−I contacts. Note that these morphologies differ from similarly appearing ones reported − for hA-rich AB/hA blends (e.g., high-impact polystyrene, HIPS) in which the AB copolymer self-assembles into bilayered (membrane) structures. In this work, hS, not the RBC, constitutes the minor component and phase-separates to form the observed channel structure.…”

Section: Resultscontrasting

confidence: 72%

“…In addition to the large hS120 domains, a few dispersed hS channel structures reminiscent of those seen in the 15/5 blend (Figure a) are also observed in the 120/20 blend (data not shown). Recall that, while membrane-like structures (e.g., vesicles) are often observed in macrophase-separated copolymer/homopolymer blends, − they are commonly the result of copolymer, not homopolymer, self-organization. A micrograph showing the interior of a lone hS120 domain is provided in Figure and demonstrates that spherical RBC inclusions ranging from 80 to 450 nm in diameter, as well as cylindrical or wormlike RBC micelles measuring about 45 nm wide, reside within the hS120 domains.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Complex Phase Behavior of a Disordered “Random” Diblock Copolymer in the Presence of a Parent Homopolymer

et al. 1997

View full text Add to dashboard Cite

Previous efforts addressing binary blends of a block copolymer and a parent homopolymer have principally employed ordered copolymers in either the intermediate- or strong-segregation regimes. In this work, blends composed of a disordered (75/25)-b-(50/50) poly[(styrene-r-isoprene)‘-b-(styrene-r-isoprene)‘‘] (S/I)‘-b-(S/I)‘‘ random diblock copolymer (RBC) and homopolystyrene (hS) have been investigated. Blend morphologies, characterized by transmission electron microscopy, are correlated with hS concentration and molecular weight, as well as with changes in the hS T g, as measured by thermal calorimetry. At low hS fractions (up to 20 wt % hS), the S/I block sequences in the RBC induce competition between attractive and repulsive interactions with hS molecules, resulting in the formation of thin hS channel structures in a continuous RBC matrix. An increase in hS concentration or molecular weight serves to broaden the channels until the morphology resembles macrophase-separated hS domains containing micelle-like RBC dispersions. In blends with relatively high hS fractions (greater than 80 wt % hS), repulsive interactions between RBC and hS molecules are responsible for the formation of macroscopic RBC domains in a continuous hS matrix. These blend morphologies demonstrate that localized interactions between homopolymer molecules and each block of a copolymer exist, and can be probed, in the disordered state.

show abstract

Section: Resultscontrasting

confidence: 72%

Section: Resultsmentioning

confidence: 99%

Complex Phase Behavior of a Disordered “Random” Diblock Copolymer in the Presence of a Parent Homopolymer

et al. 1997

View full text Add to dashboard Cite

show abstract

“…The blend of poly(vinyl chloride) and polyethylene represents an immiscible system with a discrete dispersed phase. Modification of the interface of a polymer blend with an interfacial modifier serves to reduce the interfacial tension between the parent components, − reduce the dispersed phase size, − inhibit coalescence, ,,, and improve the adhesion between the constituents in question . This is normally a prerequisite to the obtention of improved mechanical properties. − …”

Section: Introductionmentioning

confidence: 99%

Correlation between the Interfacial Tension and Dispersed Phase Morphology in Interfacially Modified Blends of LLDPE and PVC

Liang¹,

Favis²,

Yu³

et al. 1999

Macromolecules

View full text Add to dashboard Cite

To study the phase size/interfacial tension relationship for LLDPE/PVC blends over a wide range, three modifiers of widely varying efficacy were chosen based on a cursory analysis of their acid−base interactions with the blend system. The modifiers used were poly(isoprene−4-vinylpyridine) (PIP−P4VP), poly(styrene−acrylic acid) (PS−PAA), and a hydroxyl-terminated polystyrene (PS−Si(CH3)2OH). The ternary blend systems were rigorously characterized by tracking both interfacial tension and dispersed phase morphology evolution as a function of percent interfacial modifier. The interfacial tension was measured using the breaking thread technique, and the blends for morphology examination were prepared on a Brabender mixer, a predominantly shear mixing device. Both the interfacial tension and the morphology studies confirm that the best modifier was the PIP−P4VP followed by PS−Si(CH3)2OH, and the PS−PAA copolymer did not have any influence on the system whatsoever. The area occupied per molecule at the PVC/LLDPE interface estimated from the emulsification curve (morphology data) for the poly(isoprene−4-vinylpyridine) is approximately 6 nm2 per molecule. It is shown that PVC/LLDPE, due to the low interfacial tension of the unmodified blend, represents a case where the dynamic coalescence contribution to morphology development is essentially negligible. This has allowed the relationship between morphology and interfacial tension to be studied in a direct fashion. A comparison of the limiting values of morphology and interfacial tension, in the presence of the modifiers, compared to the unmodified system unambiguously indicates a close 1:1 relationship between the two in the absence of coalescence effects. This direct dependence between dispersed phase size and interfacial tension is observed for all three systems and is independent of the relative efficacy of the modifier itself. These results demonstrate a direct experimental confirmation of the interfacial tension/phase size relationship as predicted by Taylor theory.

show abstract

“…Another difficulty in physical compatibilization is that a block copolymer cannot reach the interface easily owing to its high viscosity and rather short processing times, because polymer alloys are usually prepared by extruder or compounding machine. Thus, although much work3–6, 15–17 has been published in this area, physical compatibilization is not widely used for commercial production of polymer alloys.…”

Section: Introductionmentioning

confidence: 99%

Preparation of the HIPS/MA graft copolymer and its compatibilization in HIPS/PA1010 blends

Chen

Yang

Liu

1999

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

ABSTRACT:The graft copolymer of high-impact polystyrene (HIPS) grafted with maleic anhydride (MA) (HIPS-g-MA) was prepared with melt mixing in the presence of a free-radical initiator. The grafting reaction was confirmed by infrared analyses, and the amount of MA grafted on HIPS was evaluated by a titration method. 1-5% of MA can be grafted on HIPS. HIPS-g-MA is miscible with HIPS. Its anhydride group can react with polyamide 1010 (PA1010) during melt mixing of the two components. The compatibility of HIPS-g-MA in the HIPS/PA1010 blends was evident. Evidence of reactions in the blends was confirmed in the morphology and mechanical behavior of the blends. A significant reduction in domain size was observed because of the compatibilization of HIPS-g-MA in the blends of HIPS and PA1010. The tensile mechanical properties of the prepared blends were investigated, and the fracture surfaces of the blends were examined by means of the scanning electron microscope. The improved adhesion in a 15% HIPS/75% PA1010 blend with 10% HIPS-g-MA copolymer was detected. The morphology of fibrillar ligaments formed by PA1010 connecting HIPS particles was observed.

show abstract

Enthalpic effects on interfacial adhesion of immiscible polymers compatibilized with block copolymers

Cited by 21 publications

References 27 publications

Complex Phase Behavior of a Disordered “Random” Diblock Copolymer in the Presence of a Parent Homopolymer

Complex Phase Behavior of a Disordered “Random” Diblock Copolymer in the Presence of a Parent Homopolymer

Correlation between the Interfacial Tension and Dispersed Phase Morphology in Interfacially Modified Blends of LLDPE and PVC

Preparation of the HIPS/MA graft copolymer and its compatibilization in HIPS/PA1010 blends

Contact Info

Product

Resources

About