Solid state behaviour and properties of compression moulded poly(ether ether ketone)/polysulfone blends

2006

Macro Materials & Eng

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Summary: Blends of PEI and PPSU were prepared directly during the plasticization step of an injection molding process throughout the full composition range. The molded blends were transparent and showed a single glass transition and no dispersed phase by SEM. These characteristics did not allow the presence of a single miscibilized phase to be inferred unambiguously due to the very similar Tgs and refractive indices of the two components of the blends. Miscibility was inferred after close observation of the position, height and area of the enthalpy relaxation peak of the 50/50 blend. The modulus of elasticity and yield stress changed linearly with composition, leading to polymer materials with intermediate characteristics. The linearity was attributed to the lack of decrease in free volume induced by mixing and to the similar orientation of the components before and after mixing. The PPSU presence only slightly reduced the known tendency towards brittle fracture of PEI under notched impact conditions, but the presence of a single amorphous phase led to an expected ductile behavior of the blends close to that predicted by the single rule of mixtures.

Section: Resultsmentioning

confidence: 99%

New Miscible Poly(ether imide)/Poly(phenyl sulfone) Blends

Ramiro¹,

2006

Macro Materials & Eng

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“…It is known that a small dispersed phase size is necessary to obtain compatible polymer blends 26,37,42 This is because the large stress concentrations provoked by large dispersed particles lead to early failure. The low dispersed phase size of PBT-PAE blends (0.4-1 m) is probably one reason for the observed positive behavior, which has also been seen in partially miscible blends such as polyetherimide-polyarylate 43 It is also known that, although significant exceptions exist, 44 the strain at break usually depends strongly on the blend miscibility, 26,45 and more specifically on the interfacial adhesion between components. 1 The almost linear behavior of ductility with composition displayed in Figure 11 indicates that, as was seen previously from the morphological observations, the adhesion between the blend components was good enough to allow an efficient stress transfer from the matrix to the dispersed phase.…”

Section: Mechanical Propertiesmentioning

confidence: 88%

Phase behavior and mechanical properties of blends of poly(butylene terephthalate) and poly(amino–ether) resin

Granado¹,

J of Applied Polymer Sci

2003

ABSTRACT:The structure, thermal and mechanical properties of blends of poly(butylene terephthalate) (PBT) and a poly(amino-ether) (PAE) barrier resin obtained by direct injection molding are reported. The slight shift of the glass transition temperatures (T g ) of the pure components when blended is attributed to partial miscibility rather than interchange reactions. Both the small strain and the break properties of the blends were close or even above those predicted by the direct rule of mixtures. The specific volume of the blends appeared to be the main reason for the modulus behavior. The linear values of the elongation at break indicated that the blends were compatible, and were attributed to a combination of good adhesion between the two phases of the blends and the small size of the dispersed phases.

“…Finally, a highly aromatic character of both components of the blend 25,52,53,55 has been proposed as the reason for compatibility in fully immiscible blends such as PPS with both PEI and PSU, 25 and PEEK with both PSU 52,55 and PES. 53 Both components of PEI/PC blends are also highly aromatic, with bisphenol A units in their polymer chains.…”

Section: Mechanical Propertiesmentioning

confidence: 98%

“…The occurrence of good ductility values in apparently fully immiscible blends is a rather frequent result. 25,[52][53][54][55] Therefore, other factors, such as the properties of the blend components, mentioned above, should also be taken into consideration. For instance, in a polymer blend, a lower Poisson's ratio or a higher thermal expansion coefficient of the matrix lead to compressive stress in the dispersed phase upon elongation, making debonding difficult.…”

Section: Mechanical Propertiesmentioning

confidence: 99%

Phase Structure and Mechanical Properties of Blends of Poly(ether imide) and Bisphenol A Polycarbonate

Ramiro¹,

2004

Polym J

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Poly(ether imide) (PEI)/bisphenol A polycarbonate (PC) blends were obtained throughout the composition range both by direct injection moulding (DI blends) and by extrusion followed by injection moulding (PM blends). Although some reaction was observed by FT IR, the blends were fully phase separated at the detection level of DMTA. An anomalous decrease in the high temperature T g of the 90/10 and 80/20 blends, was only seen in PM blends. This was attributed to an anomalous thermodynamic behaviour, after rejecting degradation, reactions or particle size as possible explanations. With the exception of the PC-rich DI blends, the morphology was fine and homogeneous. Both the modulus of elasticity and the yield stress were very close to those expected from the rule of mixtures, whatever the morphology. Unexpectedly, ductility followed the same trend, even in the less homogeneous PC-rich DI blends. This points to the very slight reactions observed, and to parameters related to chemical features of the components (such as the highly aromatic character of the components of the blend) as the main reasons for the observed ductility behaviour. [DOI 10.1295/polymj.36.705] KEY WORDS Poly(ether imide) / Polycarbonate / Blends / Mechanical Properties / Phase Structure / Blending thermoplastic polymers 1,2 to obtain multicomponent materials is one of the most useful ways to develop new polymeric materials. This is because the costs associated with the development of a new polymer do not usually compensate the likely profit. Moreover, the preparation and development of blends based on commercial polymers requires less time for the optimisation of the final product. Usually, the components of a blend are selected looking at complementary characteristics in processability, final properties or price. Thus, polymer blending can allow the combination, for example, of an expensive high performance polymer with a cheaper one, to obtain the expected performance at an advantageous cost.Poly(ether imide) (PEI) is a high performance amorphous thermoplastic with good thermal stability (T g ¼ 220 C) and remarkable modulus of elasticity and tensile strength. 3 It is used, among other applications, for advanced parts in electrical and electronics industry, in aircraft applications and in the automotive industry. Blends of PEI with poly(ether ether ketone) (PEEK), 4-6 aliphatic-aromatic polyesters, 7-20 polyarylate (PAr), 21,22 polyamide 6,6, 23,24 poly(phenylene sulphide) (PPS) and polysulfone of bisphenol A (PSU), 25 among others, have been studied and several patents 26 with polymers such as polycarbonate, polyamides, polypropylene, polysulfones and liquid crystal polymers, have been granted.Bisphenol A polycarbonate (PC) is an engineering thermoplastic with applications in a wide variety of fields, such as electronics, illuminating engineering, household, automotive industry, sports, security elements, etc. Its blends with many other polymers have been studied 27,28 or registered, 26 and some of them such as those with poly(ethylene terepht...