Acrylonitrile Butadiene Styrene Terpolymer Research Articles

Effect of crosslinking reactions and order of mixing on properties of compatibilized PBT/ABS blends

The low-temperature notched Izod impact strength of poly(butylene terephthalate), PBT, blends with acrylonitrile–butadiene–styrene terpolymers, ABS, can be improved by incorporating methyl methacrylate, glycidyl methacrylate, ethyl acrylate terpolymers, MGE, as a reactive compatibilizer. However, fracture properties depend on the order of mixing of the blend components. When all components of compatibilized blends are melt mixed together in a single-pass extrusion, the low-temperature toughness is improved; however, the room-temperature impact strength is reduced relative to uncompatibilized blends. Using a two-pass extrusion method where PBT and MGE are melt mixed together in a first extrusion prior to incorporating ABS in a second extrusion, the room-temperature impact strength is superior to that of blends prepared by the single-pass method. When a two-pass method is used where ABS and MGE are combined prior to extrusion with PBT, the impact properties at all temperatures are inferior to those of uncompatibilized blends. Evidence is presented which suggests that residual acids present in emulsion-made ABS material may cause a crosslinking reaction involving the epoxide functionality of MGE terpolymers resulting in a deleterious effect on the ABS mechanical properties and its blends with PBT. By changing the order of mixing, the sequence of chemical reactions which occur can be controlled to optimize blend properties.

Synthesis and properties of vinyltrimethoxysilane-EPDM-styrene graft terpolymer

The graft copolymerizations of vinyltrimethoxysilane (VTMO) and styrene (St) onto ethylene–propylene–diene terpolymer (EPDM) were carried out with benzoyl peroxide (BPO) as an initiator in toluene. The effects of EPDM concentration, mole ratio of VTMO to St, reaction time, reaction temperature, and initiator concentration on the graft copolymerizations were examined. The synthesized VTMO–EPDM–St graft terpolymers (VES) were confirmed by infrared and 1H-NMR spectroscopies. The molecular weight, thermal stability, light resistance, and weatherability of the graft terpolymer were investigated by gel permeation chromatography, thermogravimetric analysis, and Fade-o-Meter. The number-average molecular weight was 109,000. It was found that the heat resistance and light resistance as well as weatherability of VES are considerably better than those of acrylonitrile–butadiene–styrene terpolymer. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1345–1352, 1998

Synthesis and properties of vinyltrimethoxysilane–EPDM–styrene graft terpolymer

The graft copolymerizations of vinyltrimethoxysilane (VTMO) and styrene (St) onto ethylene–propylene–diene terpolymer (EPDM) were carried out with benzoyl peroxide (BPO) as an initiator in toluene. The effects of EPDM concentration, mole ratio of VTMO to St, reaction time, reaction temperature, and initiator concentration on the graft copolymerizations were examined. The synthesized VTMO–EPDM–St graft terpolymers (VES) were confirmed by infrared and 1H-NMR spectroscopies. The molecular weight, thermal stability, light resistance, and weatherability of the graft terpolymer were investigated by gel permeation chromatography, thermogravimetric analysis, and Fade-o-Meter. The number-average molecular weight was 109,000. It was found that the heat resistance and light resistance as well as weatherability of VES are considerably better than those of acrylonitrile–butadiene–styrene terpolymer. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:1345–1352, 1998

Mechanistic studies on fire retardant action of fluorinated additives in ABS

Small amounts of polytetrafluoroethylene (PTFE) are shown to modify the combustion behaviour of Acrylonitrile–Butadiene–Styrene terpolymers (ABS) fire retarded with a bromine/antimony synergistic system. PTFE makes ignition more difficult and decreases the rate of flame propagation in the early stage of combustion. The action of PTFE is shown to occur in the condensed phase by accumulation of fluorine in the residue of combustion and by reaction of PTFE with Sb2O3 to give volatile moieties. A catalytic action of fluorinated species formed in the presence of PTFE is suggested to take place on reactions of the bromine/antimony system increasing its effectiveness. © 1997 John Wiley & Sons Ltd.

On the applicability of the load separation criterion to acrylonitrile/butadiene/styrene terpolymer resins

Load separation constitutes the basis for the experimental evaluation of the J-integral by using the single-specimen technique. The objective of this present paper is to investigate the applicability of the load separation criterion for evaluating the ductile fracture mechanics parameters of acrylonitrile/butadiene/styrene (ABS) terpolymers. This criterion allows the load to be represented as the product of two separate functions, namely a material deformation function and a crack geometry function. Load separation implies a method for J-integral evaluation by using only a single load—displacement measurement. The original method for evaluating J used an energy-rate interpretation, which required several load-displacement measurements to be made for identical specimens with varying crack lengths. J methodology based on load separation introduces new parameters, i.e. η, η e1 and η p1, which greatly simplify the calculation of J and constitute the basis for the J−R multiple specimen technique. Recently, a method for both the experimental determination of the η-factors and the verification of load separation, which is based on separation constants, has been proposed for the testing of steel. This method allows the calibration of the η-factors in new test specimen geometries. This present paper attempts to evaluate experimentally whether the principle of load separation is valid when testing ABS polymers in a bending configuration in order to obtain a valid single J-testing method, and to calculate the η plastic factor experimentally by using this new simple method based on the load separation criterion in non-growing-crack measurements. In addition, a new approach based on the load separation principle which allows not only the calculation of J from a single specimen, but also the calculation of J–R curves from one test measurement has recently appeared. This approach is called the ‘normalization method’ and has already been applied to the J-testing of two rubber-toughened nylons and one ABS polymer. However, load separation has only demonstrated for different specimen geometries in steels. In addition, the load separation in ABS terpolymers has been verified in this present paper for growing cracks, by using an experimental procedure available in the literature.

Short Glass Fiber Reinforced PA 6 and ABS Blends

Abstract A 70:30 blend of polyamide 6 (PA 6) and acrylonitrile butadiene styrene terpolymer (ABS), with and without a compatibilizer, was used as the matrix for reinforcement with short glass fibers. The compatibilizer used was a copolymer of styrene maleic anhydride (SMA) and its level was kept at 5 wt.-% in the blend. The glass fiber content was varied from 10 to 30 wt.-%. The blends and corresponding composites were compounded using a single screw extruder and test samples were prepared by injection molding. Tensile, flexural and impact properties were determined using the injection molded test samples according to ASTM standards. Morphological studies were carried out on fractured tensile test specimens using scanning electron microscopy (SEM). In general, the mechanical properties improved by the addition of glass fibers to the blend matrices and increased with increasing glass fiber content. The compatibilizer (SMA) has no favorable effect on the mechanical properties of the composites although it has a significant effect on the blends of PA 6 and ABS. SMA increases the melt viscosity of the blend and its addition to the blend results in greater damage to the fibers in the composite during processing. The fiber-matrix adhesion appears to be better in the absence of SMA. The morphological observations have been correlated with mechanical properties.

Photo-oxidation of ABS: Part 2—Origin of the photodiscoloration on irradiation at long wavelengths

The reactions that lead to the discoloration of acrylonitrile-butadiene-styrene terpolymers (ABS) on exposure to long-wavelength irradiation ( λ > 300 nm) in the presence of oxygen have been studied. The photoproducts responsible for the discoloration are obtained by photo-oxidation of the polystyrene component of the styrene-acrylonitrile (SAN) macrophase. It is shown that the polystyrene oxidation is mainly initiated by radical species obtained in photo-oxidation of the polybutadiene nodules. The considerable photo-oxidability of polybutadiene accounts for the high rate of discoloration of ABS in comparison with the discoloration of polystyrene homopolymer. In conditions of accelerated artificial photo-ageing, oxygen starvation effects on the photodiscoloration of ABS are observed. Similar effects have been observed formerly in the photo-oxidation of the polybutadiene nodules.

Studies on binary and ternary blends of polypropylene with ABS and LDPE. I. Melt rheological behavior

AbstractStudies are presented on melt rheological properties of binary blend of polypropylene (PP) and acrylonitrile–butadiene–styrene terpolymer (ABS), and ternary blend of PP, ABS, and low‐den‐sity polyethylene (LDPE). Data obtained in capillary rheometer are presented to describe the effect of blending ratio, shear stress, and shear rate on flow properties, melt viscosity, and melt elasticity. At a blend composition corresponding to 10 wt % ABS content, both binary and ternary blends show maximum in melt viscosity accompanied by minimum in melt elasticity. Pseudoplasticity of the melt decreases with increasing ABS content. In ternary blends, LDPE facilitates the flow at low LDPE contents and obstructs the flow at high LDPE contents. Scanning electron microscopic studies are also presented to illustrate the state of dispersion and its variation with blend composition.

Radical concentration and efficiency of secondary photochemical reactions in modified polystyrene

AbstractThe influence of acrylonitrile‐butadiene‐styrene‐terpolymer (ABS) and methyl methacrylate‐butadiene‐styrene‐terpolymer (MBS) modifying the polystyrene (PS) films on its resistance to UV radiation were investigated.On the basis of the results of ESR, IR, UV, mass spectroscopy, viscosimetric and solubility measurements it was found that 3% of ABS or MBS in polystyrene films have a clear influence on the course of photochemical processes. After UV‐irradiation of the samples, at the presence of this terpolymers, a greater concentration of free radicals with shorter half‐life times was observed.Both terpolymers increase the productivity of photooxydation of polystyrene as well as its crosslinking and decrease its dehydrogenation.

Polypropylene/ABS terpolymer blends. Mixing and mechanical properties

A typical commercial polypropylene and acrylonitrile–butadiene–styrene terpolymer were coextruded and injection molded in various ratios and as the pure components. The rheological properties of the pure components in a single screw extruder were analyzed. Tensile and impact properties were compared with those of the pure polymers. Stress relaxation was analyzed by a simple three-element model. The data were related to the processing conditions. The morphology of the blends was inferred from extractive and staining tests on the blends.