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The present study involves the fabrication of Poly (lactic acid) (PLA) blends with natural rubber (NR) or epoxidised natural rubber with 25% and 50% epoxidation levels (ENR 25 and ENR 50) respectively to produce flexible PLA filaments for fumed deposition modelling (FDM) 3D printing. Styrene-ethylene-butylene-styrene-grafted maleic anhydride (SEBS-g-MA) as a compatibiliser was used in the PLA/NR, PLA/ENR 25, and PLA/ENR 50 blends with a fixed blend ratio of 80/20. The effects of SEBS-g-MA content ranging from 5 to 15 parts per hundred polymer (php) in the PLA/NR, PLA/ENR 25 and PLA/ENR 50 blends on the thermal properties, tensile strength, elongation at break, melt flow index (MFI) and morphological analysis were studied. Differential scanning calorimetry (DSC) demonstrated that the glass transition temperature (Tg) and melting point temperature (Tm) of PLA shifted to a higher temperature as the SEBS-g-MA content increased in the PLA blends. Furthermore, a change in the degree of crystallinity was noted as the SEBS-g-MA content increased from 5 to 15 php, directly affecting the elongation at break of the compatibilised PLA blends. Relatively, the PLA/ENR 25/SEBS-g-MA blends have a much lower Tm, enthalpy, and crystallisation degree, indicating higher compatibility than the other compatibilised PLA blends. The results are consistent with the scanning electron microscopy (SEM) analysis, which revealed a possible interaction between the MA moiety, SEBS and rubber component functional groups. The MFI is gradually reduced with the addition of SEBS-g-MA up to 15 php; however, the value is comparable to the commercial PLA filament, which is sufficient for printability study. Overall, the PLA/ENR 25 containing 15 php SEBS-g-MA achieved optimal printability as a flexible PLA filament for 3D printing, as evidenced by a tenfold increase in elongation at break of the 3D-printed parts compared to the commercial filament. [ABSTRACT FROM AUTHOR]

Owing to the different characteristics of each of the multiple polymers, obtaining a homogenous metal injection moulding (MIM) feedstock blend is challenging. Therefore, studying interactions between the polymeric components is vital for achieving suitable MIM feedstocks. We report on the effects of different compatibilisers – EGMA and E40 – on the interactions in polyoxymethylene (POM) and polypropylene (PP) blends. We measured contact angles and performed Fourier transform infrared spectroscopy and atomic force microscopy analyses to identify the suitable compatibiliser that yields a feedstock with excellent properties. It was found that the binder system based on EGMA-3 demonstrates the lowest contact angle and best miscibility for the POM/PP blends compared to E40. This enhanced interaction lies in the chemistry of EGMA, having an active site that reduces the interfacial tension between the components of the POM/PP blend. Subsequently, this creates a positive interaction between the polymers and metal powders, ensuring good adhesion within the feedstock. [ABSTRACT FROM AUTHOR]

High-density polyethylene filled with low-volume fractions of carbon nanofibers (CNFs) were prepared by melt-compounding. Two types of maleic anhydride (MAH) grafted polymers such as polypropylene-grafted-maleic anhydride (PPgMAH) and polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-graft-maleic anhydride (PSgMAH) were selected as compatibilizing agents for the nanocomposites. The combined effects of these agents along with carbon nanofiber on the morphological and thermal properties were examined. All the composites mainly displayed a strong XRD reflection peak at 21.6° followed by a less intensive peak at 24.0°, correspond to the unit cell structure of (110) and (200) reflection planes. Scherrer analyses of XRD data showed no significant changes in the crystalline nature of nanocomposites with respect to the neat PE. Microscopic examinations revealed that the dispersion of CNFs in the nanocomposite matrices was well dispersed within the matrix without leaving any voids. DSC analysis showed clear miscibility of CNF in the HDPE matrix and showed almost same melting temperature. TGA results showed that PE/CNF samples blended with PSgMAH exhibited higher thermal stability. The melt rheological analysis of HDPE/CNF composites was performed using an oscillatory rheometer. From flow curve, it could be understood that processing of these kinds of polymer nanocomposites is quite easy at moderate high shear rate. The oscillatory rheological analysis showed the shear-thinning behavior for the prepared composites. An improvement in the viscoelastic modulus was observed as the nanofiber concentration increases. The progress in the modulus values was attributed to the structural rigidity imparted by the high aspect ratio CNF. [ABSTRACT FROM AUTHOR]

Carbon black is the prime component used in tyre manufacturing. Normally, 40–60 phr of carbon black is added in rubbers to enhance their physico-mechanical properties. Utilisation of high amounts of carbon black during tyre manufacturing will certainly lead to more fly loss, which may create several health hazards to humans involved in the mixing operation. This research work aims to partially replace carbon black with minimal nanoclay and balance the technical properties of styrene butadiene rubber (SBR) compounds. Organically modified polar nanoclay namely, Cloisters 30B was used in this study. Compatibility between SBR and Cloisite 30B was enhanced by introducing carboxylated styrene butadiene rubber (XSBR) as compatibiliser. Compatibilised SBR nanocomposites were developed by means of a two-step mixing process, where the required quantity of Cloisite 30B was dispersed in XSBR through a solution mixing technique. Further, the dried XSBR-Cloisite 30B films were incorporated in the bulk SBR matrix along with carbon black and curing agents through a mechanical mixing technique. For comparison, carbon black filled SBR compounds and dual filler (carbon black and cloisite 30B) filled uncompatibilised SBR compounds were prepared directly via a mechanical mixing method. Cure characteristics, morphology, wear behaviour and mechanical properties were analysed for the prepared rubber compounds. Compatibilised styrene butadiene rubber nanocomposite containing a dual filler exhibited an increase in maximum torque, tensile strength, modulus of elasticity, storage modulus and resistance to wear proving to be potential candidature for tyre applications. The obtained results confirmed that a minimal quantity of nanoclay (3.5 phr) and carbon black (20 phr) contributed to achieve desired technical properties of SBR compounds. In addition, it was observed that the addition of carbon black enhances the distribution of nanoclay bybreaking the nanoclay agglomerates in the SBR matrix, which indeed elevates the technical properties of the related compounds. [ABSTRACT FROM AUTHOR]

Abstract Glass fibre (GF), nanoclay (NC) and hybrid composites compatibilised with maleic anhydride polypropylene (MAPP) were prepared by extrusion and injection moulding. The fourier transform infra-red spectra revealed the characteristic absorption peaks of MAPP in the compatibilised GF and NC composites. A decrement in the peak intensity of X-ray diffraction patterns of NC composite was obtained as the MAPP content increased indicating a partial exfoliation of NC. The thermogravimetric analysis showed that the incorporation of MAPP into hybrid composites reduced the thermal stability of the material. The dynamic mechanical analysis showed an increase in the storage modulus in the hybrid composites with lower content of MAPP due to the enhancement in the interfacial adhesion between the GF, NC and PP matrix.

Thermoplastic elastomer composites of polystyrene (PS) blended with styrene--butadiene rubber (SBR)--filled wollastonite were prepared using a laboratory scale internal mixer. The compatibiliser used in this study was maleic anhydride (MAH). The torque developments, morphology, and mechanical properties such as tensile strength, elongation at break, Young's modulus and impact strength were studied. PS/SBR/wollastonite composites with the addition of MAH had higher torque than PS/SBR/wollastonite composites without MAH. Tensile strength, impact strength and elongation at break were reduced by increasing filler loading, both for composites with and without MAH. Composites with MAH had higher tensile strength but lower impact strength and elongation at break as compared with composites without MAH. The Young's modulus increased with the wollastonite loading, whereas at a similar wollastonite loading, composites with MAH exhibited higher values of Young's modulus than composites without MAH. Scanning electron microscopy on fracture surfaces showed better filler--matrix adhesion for composites with MAH. [ABSTRACT FROM AUTHOR]

This paper presents the development of bipolymer nanopolymers - polyamide and polyethylene - compatibilised with polyethylenegraft- maleic anhydride and graphite nanoparticles. Polyamide/polyethylene (PA/PE) composites are studied because both components are relatively inexpensive, advantageous and are processed by injection. Compatibilisation of binary polymer compounds can be accomplished by adding a grafted copolymer, the segments of which have physical or chemical affinity with the two immiscible homopolymers. In this case, polyethylene-graft-maleic anhydride (PE-g-MA) was used. Graphite-containing polymer composites are considered a new generation of materials with predefined properties, in this case, resistance to impact. The combined effects of graphite and compatibilizing polymer (PE-g- MA) were studied on the structure and properties of the new materials. The tested nanocomposites were characterized morpho-structurally (SEM, FT-IR spectrometry) and physico-mechanically. [ABSTRACT FROM AUTHOR]

ATH filled NR/PP thermoplastic vulcanisates (TPVs) were obtained from blending natural rubber (NR), polypropylene (PP) and alumina trihydrate (ATH) by using Brabender plastograph. Maleic anhydride grafted polypropylene (MAH-g-PP) was used as compatibiliser to improve mechanical and flammability properties of TPVs. The effect of MAH-g-PP at different concentrations on the properties of ATH filled NR/PP TPVs was studied. Investigation on the microstructures of ATH filled NR/PP TPVs by mean of scanning electron microscope (SEM) and transmission electron microscope (TEM) indicated the efficient mixing of NR and PP phases and more uniform distribution of ATH in individual component of NR/PP blend due to compatibilising action of MAH-g-PP. Mechanistic model for the compatibilisation process of a structure of ATH filled NR/PP TPVs in the presence of MAH-g-PP was also proposed. With higher concentration of MAH-g-PP, the TPVs had shown increase in 100% modulus, increase in tensile strength, decrease in elongation at break and less elastic recovery. The flame resistance also increased with the addition of given amount of MAH-g-PP. However, the addition of MAH-g-PP had little influence on processing capability of the ATH filled NR/PP TPVs. Based on the present study, it was suggested that the MAH-g-PP acted as compatibility enhancer in the ATH filled NR/PP TPVs and the compatibility increase was a key to benefit the strength and flame retardancy of the NR/PP TPVs. [ABSTRACT FROM AUTHOR]

Waste based activated biochar was used to manufacture wood/polypropylene biocomposites. The biochar used had no surface functional groups, however, possessed high surface area (335 m 2 /g). Therefore, it was hypothesised that less than usual amount (3–5 wt%) of compatibiliser (maleic anhydride) could be used, to reduce production costs, while maintaining similar mechanical and flammability properties of the biocomposite. The biocomposites were characterised mechanically through tension, flexural, impact, and micro–hardness tests. The flammability and thermal behaviours were determined using cone calorimetry and thermogravimetry, respectively. Infrared spectroscopy and X–ray diffraction were also employed to comprehend the chemical changes occurring in the biocomposites. It was found that the amount of compatibiliser could be reduced to 1 wt% (from 3 wt%) without compromising on the mechanical performance (especially, tensile strength/modulus, impact strength, and micro–hardness) and flammability properties of the biocomposites. Electron microscopy revealed that the lack of compatibiliser in the biocomposites was compensated by well–dispersed biochar particles whose pores were infiltrated by the polymer causing a mechanical interlocking. In general, addition of biochar improved the mechanical and fire performance of the biocomposites compared to the neat polymer. Reduction of compatibiliser to 1 wt% from 3 wt% in conjunction with biochar saves ∼18% of the biocomposite production costs. [ABSTRACT FROM AUTHOR]

In silica-filled natural rubber, it is essential to use coupling agents or compatibilisers to enhance filler-rubber interactions, reduce silica network formation and hence to obtain good reinforcement. This work investigates the effect of epoxidised low molecular weight natural rubber (ELMWNR) in silica-filled NR compounds on processing, mechanical, dynamic-mechanical and morphological properties. ELMWNRs with 12 and 28 mol% epoxide groups having a molecular weight in the range of 50,000-60,000 g/mol were added into the compounds as compatibilisers at varying loadings from 0-15 phr. The reference compound containing bis-(triethoxysilylpropyl) tetrasulfide (TESPT) as coupling agent was also prepared for comparison. The addition of 10 phr ELMWNR-28 in the silica-filled NR compounds not only decreases mixing torque, compound viscosity and Payne effect to the levels close to those of the compound with TESPT, but also increases bound rubber content and filler dispersion resulting in improvement of mechanical properties. However, the TESPT-silica system still provides better mechanical and dynamic mechanical properties compared to the alternative ELMWNR-silica systems. Overall, ELMWNR can be an alternative as natural-based compatibiliser with no ethanol emission like in the case with TESPT. [ABSTRACT FROM AUTHOR]

Rice husk and nanoclay (montmorillonite)-filled low-density polyethylene composite films were prepared by extrusion blown film. Maleic anhydride-modified polyethylene was used as compatibiliser in various concentrations ranging from 0 to 8 parts per hundred. X-ray difractograms showed an increase in interlayer spacing of montmorillonite from the use of compatibiliser when compared to the uncompatibilised composites; an increase of 20, 33, 36 and 38% for 2, 4, 6 and 8 parts per hundred, respectively, of maleic anhydride-modified polyethylene. With the incorporation of maleic anhydride-modified polyethylene, a better dispersion of the fillers was also achieved, as confirmed by scanning electron microscopy. The compatibilised composite films showed improved tensile and barrier properties. The addition of 4 parts per hundred of the compatibiliser resulted in an improvement by 22% in tensile strength. Furthermore, oxygen barrier property of the composite films improved more than twofold by adding 4 parts per hundred of maleic anhydride-modified polyethylene. This improvement in tensile and barrier properties is due to an increase in the interfacial adhesion between the fibre and matrix and better dispersion of impermeable nanoparticles. [ABSTRACT FROM PUBLISHER]

The use of natural fibres in the development of composite materials is a sector in full expansion. These fibres were used for their low cost, availability and renewable character. The fibres of the palm (palm tree) were used as reinforcement in polypropylene. The date palm fibres have some potential because of their ecological and economic interest. Both unmodified and compatibilised fibres are used. Compatibilisation was carried out with the use of maleic anhydride copolymers. The morphology and mechanical properties were characterised by scanning electron microscopy and tensile tests. The influence of fibre content on mechanical properties of composite polypropylene/date palm has been evaluated and demonstrated that the maximum stress and elongation decreases with increasing fibre content, on the contrary, they notice an increase of the tensile modulus, but after the improvement of fibres, the maximum stress increase significantly up to 25% weight. [ABSTRACT FROM AUTHOR]

Blending polymers is widely used for the preparation of new materials. The disadvantage of this application is that the polymer components are usually not compatible and the preparation of blends with suitable (mainly processing and mechanical) properties is not satisfactory. The use of a third compound, called a compatibiliser, is an effective way to ameliorate the end-use properties of the blend. Compatibilisers based on grafted or block copolymers are often used. The present contribution deals with the compatibilisation of polypropylene/polyamide blends with compatibilisers based on grafted or block polyole- fines. [ABSTRACT FROM AUTHOR]

Natural weathering was performed on poly(butylene succinate) (PBS) and its kenaf bast fibre (KBF) filled composites by exposing the specimens to a tropical climate for a period of 6 months (max-min temperature: 31.5-23.9 °C; relative humidity: 78.9%). The aim of this study was to investigate the effects of KBF loading and the addition of maleated PBS compatibiliser (PBSgMA) on the performance of the composites under natural weathering. As expected, the flexural properties of both the uncompatibilised and compatibilised composites dropped with increasing exposure time. The weathered specimens were also assessed by colour change analysis, FTIR spectroscopy analysis and SEM examination. The total colour change, ΔE, of both the uncompatibilised and compatibilised composites increased with weathering time. FTIR spectroscopy analysis confirmed the presence of oxidation products such as hydroxyl, carbonyl and vinyl species in the weathered uncompatibilised and compatibilised composites. SEM examination revealed the presence of surface defects such as cracking, tiny holes and degraded fibre, which explain the poor performance of the composites upon weathering. [ABSTRACT FROM AUTHOR]

The effect of compatibilisers on mechanical, water absorption and morphological properties of feldspar/PP composites was investigated. Two types of compatibilisers namely; polyethylene co-acrylic acid (PEAA) and PP grafted-maleic anhydride (PP-g-MAH) were used in this study. The processability of the composites improved with the addition of PEAA and PP-g-MAH. The tensile strength, elongation at break, Young's modulus and impact strength increased with the presence of both compatibilisers. Morphological investigation using scanning electron microscopy (SEM) revealed that the improvement in tensile strength and elongation at break was due to enhancement of the interfacial adhesion between feldspar and PP. Less percentage of water absorption was observed in feldspar/PP composites with PP-g-MAH than the feldspar/PP composites with PEAA and control composites (without compatibilizers). [ABSTRACT FROM AUTHOR]

Thermoplastic polyurethanes (TPU) (based on ether and ester polyols) were blended with nonpolar material of PP. Nanoclay was used to reduce the surface energy of the TPU hard segments and makes them more compatible with the non-polar PP. More compatible blends have been obtained by using MA-g-PP as the compatibiliser. Blends were produced by melt mixing using a twin crew extruder. Compared to the ether-TPU based blend nanocomposites, the ester-TPU blends show better compatibility as confirmed by DMA, Tensile strength, XRD, SEM, and AFM analysis. [ABSTRACT FROM AUTHOR]

While the main goal of the first part of this study was to check the applicability of the Tsai–Hill equation to a polymer-polymer microfibril reinforced composite (MFC), in which the reinforcing elements represented microfibrils with a diameter around 1–3 μm and aspect ratio of about 100, in the present paper a similar goal involves the Halpin–Tsai equation. In addition, using compatibilised blends an attempt is made to shed light on the mechanism of the microfibril formation during drawing of isotropic polymer blends. For this purpose, injection moulded dog-bone test samples of blends of polypropylene/poly(ethylene terephthalate) (PP/PET) (60/40 wt%) have been prepared starting from highly drawn bristles, also from blends containing 0–9 wt% compatibiliser (ethylene-glycidyl methacrylate). The MFC structure of the test sample is established by X-ray and scanning electron microscope (SEM) analyses. The tensile data are compared with those predicted according to the Halpin–Tsai equation. It is shown that the predicted values are slightly higher than the measured ones and this finding is explained by the presence of a compatibiliser resulting in much lower aspect ratios of the microfibrils. The suggested mechanism of the microfibril formation is based on the coalescence of the individual elongated spheres during drawing. The SEM observations also show that the compatibilised blends contain much shorter microfibrils because the compatibiliser prevents the coalescence process. [ABSTRACT FROM AUTHOR]

Abstract: The morphology and thermal behaviour of polypropylene/polyamide 6 (PP/PA6), polypropylene/copolymer ethylene propylene diene (PP/PEBAX) and polypropylene/rigid polyurethane (PP/PUR) blends compatibilised with polypropylene-graft-maleic anhydride (PP-g-MA) were studied using scanning electron microscopy and thermogravimetric analyses. The study focuses on the influence of different blends obtained by mixing a thermoplastic, thermoplastic elastomer or thermoset with PP, compatibilised with PP-g-MA. The compatibilising effect of PP-g-MA in an immiscible PP/PA6 blend induces a homogeneous dispersion due to interfacial adhesion. For the PP/PEBAX and PP/PUR binary blends studied slight changes in the morphology were observed with a continuous phase but the PEBAX or PUR domains remained in the PP matrix. The deconvolution of the TGA curve permitted an evaluation of the decomposition stage of the undiluted and blend systems. Thermal stability is slightly influenced by the position of the maximum decomposition rate temperature of the first derivative thermogravimetric curve (DTG). However, the DTG curve profile remains consistent. The activation energy of undiluted PP was in the range of 162–169kJmol−1 determined by the Ozawa method. The stabilized activation energy value for all blends studied above a 0.4 weight-loss fraction is discussed. [Copyright &y& Elsevier]

Abstract: A high-content starch/low-density polyethylene (LDPE) blend with acceptable biodegradation and mechanical properties was produced by adjusting the compatibility of the blend system and processing plasticisation through the compatibiliser and different processing method. Two kinds of compatibilisers, maleic anhydride grafted LDPE after plasma treatment (MA-g-PLDPE) and acrylic acid grafted LDPE after plasma treatment (AAc-g-PLDPE), were synthesized and used in this work. The grafting degree (GD) of MA-g-PLDPE was 1.90×10−4 mol/g. The GD of AAc-g-PLDPE was 2.5×10−4 mol/g. MA-g-PLDPE gave more compatibility than AAc-g-PLDPE by the anhydride groups. The plasticisation effect by the oligomer resulted from a different process by mixing the MA-g-PLDPE and/or maleic anhydride (MA) with glycerol before compounding was investigated. As the MA and compatibiliser/LDPE premixed with GA for 30min, the LDPE particle size of blends decreased with increasing compatibiliser content. If the free MA was not added, the PE blends show irregular shapes. The weight loss of all samples achieved above 65wt% after two weeks of biodegradation. The weight losses of blends that contain free MA were higher than those without free MA. Finally, the structure of blends after soil burial was observed by SEM. [Copyright &y& Elsevier]

The influence of screw speed, agitator configuration, and compatibiliser, namely maleated polypropylene (mPP), during twin[hyphen]screw extrusion upon the morphology, dispersion stability, and properties of polyamide[hyphen]6/polypropylene (PA6/iPP) blends has been investigated. For mPP contents of 2.4 vol[percnt] and greater, the number average domain diameters measured in the extruded compound, Dn(ex), were found to decrease to a limiting value at the specific mechanical energy input, Se, around 0.07 kW h kg−1, when Se was controlled by the screw configuration and screw speed. For mixing energies greater than 0.07 kW h kg−1, the domain size was principally determined by the ratio of specific interfacial area, Sext, between the PA and iPP phases to the estimated volume fraction of in situ formed copolymer, φc; Sext/φc≈45 μm−1. The difference, ΔDn, between Dn(ex) and the average domain diameter measured in the cores of the samples after injection moulding, Dn(m), was calculated: ΔDn[equals]&z.sfnc;Dn(ext)−Dn(m)&z.sfnc;. It was found that ΔDn∝Dn(ext); i.e. larger droplets in the extrudate underwent the greatest changes in dimension in the subsequent moulding process. [Copyright &y& Elsevier]

Electron-beam (EB) irradiation technique has been used to improve the properties of 60/40 blends of NR/LLDPE in the presence of compatibilisers such as LNR-6 and LNR-16. Improvement in the physical properties of the blend correspond with the increase in the interactions created by EB irradiation as measured by gel content. For this blend ratio, the radiation dose of 200 kGy is found to be optimum. While LNR-6 shows some complimentary effects when it is used together with EB irradiation technique; LNR-16, however, causes an imperfection effect in the blend. The crosslinking process that takes place as a result of EB irradiation occurs at the expense of crystalline arrangement of the semi-crystalline LLDPE. For the morphological fixation purposes EB irradiation technique is found to be very effective. [Copyright &y& Elsevier]

The fire performance of intumescent PP/APP/PA6/EVA19 blends were previously put forward in part I of this article. In the present part, the thermal and thermo-oxidative degradations of the formulations are modelled. The comparison between the kinetic data determined in this study and data from previous studies suggests that PP degrades before the reaction between APP and PA6. However it may be supposed that in the conditions of a fire (i.e. at high heating rate) both reactions occur simultaneously. Thus the development of an efficient protective structure is possible which could explain the fire properties of interest observed in the conditions of the cone calorimeter. [Copyright &y& Elsevier]