The phase inversion and morphology of nylon 1010/polypropylene blends

Noncompatibilized and compatibilized blends of nylon 1010/PP blends having five different viscosity ratios were prepared by melt extrusion. Glycidyl methacrylate-grafted-polypro-pylene (PP-g-GMA) was used as the compatibilizer to enbance the adhesion between the two polymers and to stabilize the blend morphology. The effect of the viscosity ratio on the morphology of nylon 1010/polypropylene blends was investigated, with primary attention to the phase-inversion behavior and the average particle size of the dispersed phase. The relationship between the mechanical properties and the phase-inversion composition was investigated as well. Investigation of the morphology of the blends by microscopy indicated that the smaller the viscosity ratio (ηpp/ηpa) the smaller was the polypropylene concentration at which the phase inversion took place and polypropylene became the continuous phase. The compatibilizer induced a sharp reduction of particle size, but did not have a major effect on the phase-inversion point. An improvement in the mechanical properties was found when nylon 1010 provided the matrix phase. © 1996 John Wiley & Sons, Inc.     

Improving the foaming and mechanical properties of the in situ microfiber-reinforced polyethylene terephthalate/polypropylene composites through compatibilization

The in situ microfiber-reinforced polyethylene terephthalate/isotactic polypropylene (15/85, w/w) composite (PET/iPP MRC) was successfully obtained through the micro-nano-laminating co-extrusion by using polypropylene-grafted-glycidyl methacrylate (PP-g-GMA) as a compatibilizer. The effect of the compatibilizer on the rheological behavior, micromorphology of PET/iPP MRC, foaming capability and the mechanical properties of foamed PET/iPP MRC was investigated. Extensional rheology measurement revealed the strain hardening of PET/iPP MRC is more obviously than iPP and with compatibilizer added. Scanning electron microscope observation indicated that the introduction of PP-g-GMA compatibilizer can improve the compatibility between PET and PP and subsequently lead to the decrease of diameter of PET microfibers. In addition, the incorporating of PP-g-GMA compatibilizer can also decrease the diameter and enhance the cell density of PET/iPP MRC cell. Both the tensile strength and the impact strength of the PET/iPP MRC foam are higher than that of the iPP foam, and improved with the compatibilizer added.     

Compatibilization of polyethylene terephthalate/polypropylene blends with styrene–ethylene/butylene–styrene (SEBS) block copolymers

Blends of polyethylene terephthalate (PET) and polypropylene (PP) at compositions 20/80 and 80/20 were modified with three different styrene–ethylene/butyl–ene-styrene (SEBS) triblock copolymers with the aim of improving the compatibility and in particular the toughness of the blends. The compatibilizers involved an unfunctionalized SEBS and two functionalized grades containing either maleic anhydride (SEBS-g-MAH) or glycidyl methacrylate (SEBS-g-GMA) grafted to the midblock. The effects of the compatibilizers were evaluated by studies on morphology and mechanical, thermal and rheological properties of the blends. The additon of 5 wt % of a SEBS copolymer was found to stabilize the blend morphology and to improve the impact strength. The effect was, however, far more pronounced with the functionalized copolymers. Particularly high toughness combined with rather high stiffness was achieved with SEBS-g-GMA for the PET-rich composition. Addition of the functionalized SEBS copolymers resulted in a finer dispersion of the minor phase and clearly improved interfacial adhesion. Shifts in the glass transition temperature of the PET phase and increase in the melt viscosity of the compatibilized blends indicated enhanced interactions between the discrete PET and PP phases induced by the functionalized compatibilizer, in particular SEBS-g-GMA. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:241–249, 1997     

Study on compatibilization of polypropylene-liquid crystalline polymer blends

The mechanical properties, melt rheology, and morphology of binary blends comprised of two polypropylene (PP) grades and two liquid crystalline polymers (LCP) have been studied. Compatibilization with polypropylene grafted with maleic anhydride (PP-g-MAH) has been attempted. A moderate increase in the tensile moduli and no enhancements in tensile strength have been revealed. Those findings have been attributed to the morphology of the blends, which is predominantly of the disperse mode. LCP fibers responsible for mechanical reinforcement were only exceptionally evidenced. Discussion of PP-LCP interfacial characteristics with respect to mechanical properties-morphology interrelations allowed evaluation of the compatibilizing efficiency of PP-g-MAH. Factors important for successful reinforcement of PP with LCP have been specified. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 969–980, 1997     

Improved compatibility of PET/HDPE blend by using GMA grafted thermoplastic elastomer

ABSTRACT

Herein, graft-modified ethylene-1-octene copolymer (POE-g-GMA) and styrene-butadiene-styrene triblock copolymer (SBS-g-GMA) were found to be excellent reactive compatibilizers for immiscible poly(ethylene terephthalate) (PET)/high-density polyethylene (HDPE) blends via in-situ reaction compatibilization. With increase in compatibilizer amount, uniform phase morphology was observed in all the blends. Thus, exhibiting enhanced mechanical properties, especially, the notched Izod impact strength. In comparison with SBS-g-GMA, compatibilizer POE-g-GMA demonstrated greater impact on the compatibility. The addition of 15% POE-g-GMA produced blends with best mechanical properties. Besides, both POE-g-GMA and SBS-g-GMA enhanced the melt viscosity of PET/HDPE blends.     

Preparation of PBT/POE-g-GMA/PP ternary blends with good rigidity–toughness balance by core–shell particles

Compared with poly(butylene terephthalate)/glycidyl methacrylate grafted poly(ethylene–octene) (PBT/POE-g-GMA) binary blends, supertough PBT-based ternary blends with little rigidity loss were successfully obtained by adding rigid polypropylene (PP) into PBT/POE-g-GMA blends to construct core–shell particles during melt blending. The effects of PP content and type on the phase morphology and mechanical properties of the blends were systematically investigated. Theoretical predictions and scanning electron microscopy observation showed that a core–shell structure was formed in PBT matrix with PP as the core and POE-g-GMA as the shell. The mechanical property tests showed that POE-g-GMA and PP had significant synergistic toughening effect. When PP with high melt flow index (H-PP) was used, PBT/POE-g-GMA/H-PP (70/15/15) blends possessed the highest Izod notched impact strength, which was 1.9-fold compared with PBT/POE-g-GMA (70/30) binary blends, while the tensile performance loss was little. The essential work of fracture tests was performed to evaluate the fracture resistance of different samples. The results demonstrated that PBT/POE-g-GMA/PP ternary blends possessed much better resistance to crack propagation than PBT/POE-g-GMA binary blends. The decrease of interparticle distance and the fibrillation of core–shell particles activated intense matrix shear yielding, which was the reason for the high crack resistance of ternary blends. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48872.     

Morphological,thermal, rheological,and mechanical properties of PP/EVOH blends compatibilized with PP‐g‐IA

We prepared some blends of polypropylene (PP) and ethylene vinyl alcohol (EVOH) with and without a compatibilizer. As a new compatibilizer, we synthesized polypropylene grafted with itaconic acid (PP‐g‐IA) using Brabender mixing system. We investigated the morphological, thermal, rheological, and mechanical properties of a compatibilized blends (PP/EVOH/PP‐g‐IA) and not compatibilized blends (PP/EVOH). Our experiments showed that carboxylic acid groups in PP‐g‐IA and hydroxyl group in EVOH formed strong in situ hydrogen bond in the compatibilized blends, resulting in better morphological and mechanical properties of the compatibilized blends than those of not compatibilized blends. POLYM. ENG. SCI., 56:1240–1247, 2016. © 2016 Society of Plastics Engineers     

Rheological,thermal, and morphological properties of blends based on poly(propylene), ethylene propylene rubber,and ethylene-1-octene copolymer that could result from end of life vehicles: Effect of maleic anhydride grafted poly(propylene)

The objective of this work is to study the properties of blends that could result from the recycling of end-of-life vehicles (ELV). While ethylene propylene rubber (EPR) and ethylene propylene diene monomer (EPDM) have been used extensively as elastomeric additives in poly(propylene) (PP), they can be substituted by ethylene-1-octene copolymer (EOC). As a consequence, the matter resulting from the sorting of ELV might be more complex and made of PP, EPR, and EOC. The effect of incorporating EOC [that is a polyethylene elastomer (PEE)] and maleic anhydride grafted polypropylene (PP-g-MAH) on the rheological, thermal, and morphological properties of PP/EPR blends has been investigated. Blends of various compositions (with and without compatibilizer) were prepared using a corotating twin-screw extruder. The results were compared to the ones presented by a commercial (PP/EPR) blend. The EPR phase is dispersed in the form of spherical particles in (PP/EPR). The EOC phase is dispersed in the form of aggregated particles. Dynamic viscoelastic and differential scanning calorimetry properties of (PP/EPR)/EOC blends shows the incompatibility of the components even in presence of PP-g-MAH copolymer. POLYM. ENG. SCI., 47:1009–1015, 2007. © 2007 Society of Plastics Engineers     

An investigation on the role of GMA grafting degree on the efficiency of PET/PP-<Emphasis Type="Italic">g</Emphasis>-GMA reactive blending: morphology and mechanical properties

Glycidyl methacrylate (GMA) has been grafted on polypropylene (PP) with the aid of styrene (St) comonomer, by changing dicumyl peroxide initiator content, GMA level, and St concentration. The performance of the resulting PP-g-GMA reactive material towards static and dynamic mechanical properties of poly (ethylene terephthalate) (PET) was monitored in terms of grafting reaction variables and compatibilizer content. Fourier transform infrared spectroscopy, scanning electron microscopy, mechanical properties, melt flow rate, and impact strength analyses were applied to correlate structural changes due to grafting (or undesired chain scission) with blends’ properties. The competition between the desired reaction, i.e., GMA grafting onto PP chain, and undesired chain scission of PP macroradicals due to thermal degradation, was discussed based on torque–time curves and mechanical properties. Manipulation of grafting variables was responsible for a special behavior over properties, means that optimal or ascending/descending trends, which noticed high sensitivity of PET toughening to GMA grafting efficiency.     

Effect of blend ratio on bulk properties and matrix-fibril morphology of polypropylene/nylon 6 polyblend fibers

Ternary blends of polypropylene (PP), nylon 6 (N6) and polypropylene grafted with maleic anhydride (PP/N6/PP-g-MAH) as compatibilizer with up to 50 wt% of N6 were investigated. PP-g-MAH content was varied from 2.5 to 10%. Blends of the two polymers PP/N6 (80/20) without the compatibilizer were also prepared using an internal batch mixer and studied. The ternary blends showed different rheological properties at low and high shear rates. The difference depended on the amount of N6 dispersed phase. Co-continuous morphology was observed for the blend containing 50% N6. This blend also exhibited higher viscosity at low shear rate and lower viscosity at high shear rates than the value calculated by the simple rule of mixture. At higher shear rates, viscosity was lower than that given by the rule of mixture for all blend ratios. An increase in viscosity was observed in the 80/20 PP/N6 blend after the concentration of the interfacial agent (PP-g-MAH) was increased. Polyblends containing up to 30% N6 could be successfully melt spun into fibers. DSC results showed that dispersed and matrix phases in the fiber maintained crystallinity comparable to or better than the corresponding values found in the neat fibers. The dispersed phase was found to contain fibrils. By using SEM and LSCM analyses we were able to show that the N6 droplets coalesced during melt spinning which led to the development of fibrillar morphology.     

Mechanical and Morphological Properties of Polypropylene and Regenerated Tire-Rubber Blends

Mechanical properties and morphology of blends prepared from polypropylene (PP) and 5–20 wt% of regenerated tire-rubber (RgR) were studied. The samples were prepared in a twin-screw extruder. The addition of maleic anhydride-functionalized polypropylene (PP-g-MAH) was also investigated. Tensile and flexural moduli, tensile strength at break, elongation at break and Izod impact resistance at 23°C were increased by the addition of 15 wt% of regenerated rubber and 5 wt% of PP-g-MAH. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses showed some interaction between PP and RgR and considerable modification of the compatibilized mixture morphology. The fracture surface of the blend with PP-g-MAH showed a better interaction between the PP matrix and the regenerated rubber domains, for all blends. Well-dispersed particles of the rubber in the polypropylene matrix were observed. DSC showed that PP crystallizes on cooling at lower temperatures as the RgR content increases. The decrease in crystallization temperature is more evident for blends with 5 wt% PP-g-MAH.     

Compatibilization and morphology development of immiscible ternary polymer blends

We report a novel and effective strategy that compatibilizes three immiscible polymers, polyolefins, styrene polymers, and engineering plastics, achieved by using a polyolefin-based multi-phase compatibilizer. Compatibilizing effect and morphology development are investigated in a model ternary immiscible polymer blends consisting of polypropylene (PP)/polystyrene(PS)/polyamide(PA6) and a multi-phase compatibilizer (PP-g-(MAH-co-St) as prepared by maleic anhydride (MAH) and styrene (St) dual monomers melt grafting PP. Scanning electron microscopy (SEM) results indicate that, as a multi-phase compatibilizer, PP-g-(MAH-co-St) shows effective compatibilization in the PP/PS/PA6 blends. The particle size of both PS and PA6 is greatly decreased due to the addition of multi-phase compatibilizer, while the interfacial adhesion in immiscible pairs is increased. This good compatibilizing effect is promising for developing a new, technologically attractive method for achieving compatibilization of immiscible multi-component polymer blends as well as for recycling and reusing of such blends. For phase morphology development, the morphology of PP/PS/PA6 (70/15/15) uncompatibilized blend reveals that the blend is constituted from PP matrix in which are dispersed composite droplets of PA6 core encapsulated by PS phase. Whereas, the compatibilized blend shows the three components strongly interact with each other, i.e. multi-phase compatibilizer has good compatibilization between the various immiscible pairs. For the 40/30/30 blend, the morphology changed from a three-phase co-continuous morphology (uncompatibilized) to the dispersed droplets of PA6 and PS in the PP matrix (compatibilized).     

Blends of recycled polycarbonate and acrylonitrile–butadiene–styrene: comparing the effect of reactive compatibilizers on mechanical and morphological properties

Blends of recycled polycarbonate (PC) and acrylonitrile–butadiene–styrene (ABS) were prepared and some mechanical and morphological properties were investigated. To compatibilize these blends, ABS‐g‐(maleic anhydride) (ABS‐g‐MA) and (ethylene–vinyl acetate)‐g‐(maleic anhydride) (EVA‐g‐MA) with similar degree of grafting of 1.5% were used. To compare the effect of the type of compatibilizer on mechanical properties, blends were prepared using 3, 5 and 10 phr of each compatibilizer. A co‐rotating twin‐screw extruder was used for blending. The results showed that ABS‐g‐MA had no significant effect on the tensile strength of the blends while EVA‐g‐MA decreased the tensile strength, the maximum decrease being about 9.6% when using 10 phr of this compatibilizer. The results of notched Charpy impact strength tests showed that EVA‐g‐MA increased the impact strength of blends more than ABS‐g‐MA. The maximum value of this increase occurred when using 5 phr of each compatibilizer, it being about 54% for ABS‐g‐MA and 165% for EVA‐g‐MA. Scanning electron microscopy micrographs showed that the particle size of the dispersed phase was decreased in the continuous phase of PC by using the compatibilizers. Moreover, a blend without compatibilizer showed brittle behaviour while the blends containing compatibilizer showed ductile behaviour in fracture. © 2013 Society of Chemical Industry     

Mechanical and morphological properties of elastomer-modified polypropylene/polyamide-6 blends

Polypropylene/polyamide-6 (70:30) blends, containing dispersed discrete polyamide-6 microphases as matrix reinforcement, represent attractive materials for engineering applications. In order to enhance impact resistance, ethene/propene (EPM) was incorporated as a second separately dispersed microphase using reactive blending technology. Blend morphologies were controlled by adding maleic-anhydride-grafted-polypropylene (PP-g-MA) as compatibilizer during melt processing, thus enhancing dispersion and interfacial adhesion of the polyamide-6 phase. With PP-g-MA volume fractions increasing from 2.5 to 10 vol %, much finer dispersions of discrete polyamide-6 with average domain sizes decreasing from 8 to 0.8 μm were obtained. When polyamide-6 and ethene/propene (EPM)-rubber are dispersed simultaneously in the polypropylene matrix, impact resistance was improved. The influence of PP-g-MA volume fraction and blend morphologies on mechanical properties such as Young's modulus, yield stress, notched Charpy impact resistance was investigated. The ternary polypropylene/polyamide-6/EPM blend properties were compared with those of binary polypropylene blends containing the equivalent volume fraction of EPM. © 1995 John Wiley & Sons, Inc.     

Morphological,Thermal and Mechanical Properties of Polypropylene and Vermiculite Blends

Morphological, thermal and mechanical properties of blends prepared from polypropylene (PP) and 1, 3 and 5 wt% of vermiculite (VMT) were studied. The samples were prepared in a twin-screw extruder. The addition of maleic anhydride-functionalized polypropylene (PP-g-MAH) was also investigated. The blend morphologies were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The thermal properties of the composites were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The DSC results showed that PP crystallizes on cooling at higher temperatures as VMT content increases. The increase in crystallization temperature was most evident for blends with 5 wt% VMT. The TGA results showed that the use of VMT particles to fill polypropylene increased the thermal stability of the composite. The mechanical properties, tensile modulus and tensile strength at yield point of the PP improved by the presence of VMT.     

The Study of Reactively Compatibilized mPPO/PP Blend Systems

Polymer blends of commercial polyphenylene oxide (mPPO) and polypropylene (PP) are immiscible and incompatible in blend system. Maleic anhydride-grafted-copolymer has been employed as in situ compatibilizer for the mPPO and PP blends. This copolymer contains reactive anhydride functional groups that were able to react with mPPO at [sbnd]CH₃ side methyl groups [sbnd]OH terminal groups under the melt conditions. The PP-g-MA copolymer reduces the interfacial tension between the two polymers and act as a bridge between them to make compatible. The blends have been characterized using FTIR, SEM, and its mechanical behavior.     

Effect of processing conditions and properties of PP/nylon 6 blends

Polypropylene (PP) and nylon 6 were melt blended in a twin screw extruder at different screw speeds using malefic anhydride grafted polypropylene (MA-g-PP) as a compatibilizer. Different compositions were injection moulded and the mechanical properties, rheological behaviour and morphology of the resulting blends were studied. The impact strength and tensile strength of PP increased due to the addition of nylon 6 and MA-g-PP acted as a compatibilizer. Mechanical data suggested that blending at higher shear rates-gave better properties. An amount of compatibilizer at the 3 parts level offered optimum properties.     

Functionalization of polypropylene with oxazoline and reactive blending of PP with PBT in a corotating twin-screw extruder

The aim of this study was to prepare a compatibilized PP/PBT blend in a twin-screw extruder, using oxazoline-functionalized PP. First we prepared the functionalized PP (PP-g-OXA), and then we used it as a compatibilizer in the subsequent reactive blending stage. Polypropylene was successfully functionalized by ricinoloxazoline maleinate in a corotating twin-screw extruder using a melt free radical grafting technique. Grafting yields up to 2.1 phr were achieved. This functionalized PP used as a compatibilizer markedly improved the mechanical properties of the uncompatibilized PP/PBT (PBT content 30 wt %) blend. Significant improvements were observed, especially in impact strength (Charpy) and elongation at break of the compatibilized blends. The increased interactions between the phases were characterized by SEM analysis, DMTA, and DSC experiments. The properties of the blend greatly depended on the degradation of the PP during grafting. An optimal content of compatibilizer exists, which is dependent on the degradation of PP, grafting yield of oxazoline monomer, and on the amount of free, ungrafted monomer present in the compatibilizer. These factors can be adjusted by properly choosing the processing conditions and chemical parameters. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 883–894, 1997     

Novel strategy for ternary polymer blend compatibilization

A novel strategy for compatibilization of ternary polymer blends was described. PP (polyolefins)/PA6 (engineering plastics)/PS (styrene polymers) was selected as a model ternary blend system, and the compatibilization effect was investigated by means of SEM, rheometer, dynamic mechanical thermal analysis and mechanical testing. The results indicated that, as a ternary polymer blend compatibilizer, styrene and maleic anhydride dual monomers melt grafted polypropylene [PP-g-(MAH-co-St)] showed more effective compatibilization in the PP/PA6/PS ternary blend system than PP-g-MAH, PP-g-St and their mixture. The good compatibilizing effect of PP-g-(MAH-co-St) can be explained by two mechanisms. One is the in situ formation of [PP-g-(MAH-co-St)]-g-PA6 copolymer at the PP/PA6 interface, and the other is that it also contains styrene blocks, resulting in chemical affinity with PS and PP homopolymers.     

Effects of the compatibilizer PP-g-GMA on morphology and mechanical properties of PP/PC blends

Effects of the compatibilizer polypropylene grafted with glycidyl methacrylate(PP-g-GMA) on the morphology, thermal, rheological and mechanical properties of polypropylene and polycarbonate blends (PP/PC) were studied. It was found that the addition of PP-g-GMA significantly changed their morphology. The mean size of domains reduced from 20 μm to less than 5 μm. The dispersed domain size is also strongly dependent upon the content of PP-g-GMA. The interfacial tension of PP/PC/PP-g-GMA (50/30/20) is only about one-tenth of PP/PC (70/30). The crystallization temperature of PP in PP/PC/PP-g-GMA is 5–8°C higher than that of PP in PP/PC blends. Characterization studies based on mechanical properties, differential scanning calorimetry, rheology and morphological evidence obtained by using scanning electron microscopy support the hypothesis that an in-situ copolymer PP-g-PC was formed during the blending process.