Types Of Compatibilizers Research Articles

Synergistic effects of dual reactive compatibilizers for high-performance fully biodegradable polylactic acid/poly (butyleneadipate-co-terephthalate) composites

The PLA-g-(GMA-co-St) graft copolymer (PGS) was prepared using melt-free radical grafting technology, PGS and ESO were simultaneously employed as compatibilizers for the poly (lactic acid)/poly (butylene adipate-co-terephthalate) (PLA/PBAT) blends. The effects of the type and amount of compatibilizers on the properties of the blends were studied. The results reveal that the epoxy groups in PGS and ESO can interact with the terminal groups of PLA and PBAT. The incorporation of either PGS or ESO separately can improve the compatibility between PLA and PBAT to a considerable degree. However, the introduction of both compatibilizers into the PLA/PBAT blends results in a notable shift of the Tg of the two phases, reduces the size of PBAT particles, and makes their dispersion more uniform. This reveals that the dual reactive compatibilizers can achieve a synergistic effect, significantly reducing the interfacial tension between the two phases and facilitating inter-phase dispersion, ultimately forming a more uniform microstructure. Simultaneously, as the amount of ESO added to the blends gradually increases, the vicat softening temperature and complete decomposition temperature of the blends continue to increase, the notched impact strength and elongation at the break of the blend gradually increase and then decrease. When the ESO amount reaches 4 wt%, the performance of each property increases to 88.9 °C, 447.66 °C, 335.16 %, and 23,359.30 J/m2, respectively. At this point, the fracture surface of the blend samples is accompanied by a large-scale plastic deformation. In conclusion, this work represents the first attempt to accomplish synergistic effects via dual reactive compatibilizers. Under the best formulation and processing circumstances, the PLA/PBAT blends greatly increase their overall performance while maintaining biodegradability, hence broadening their application prospects in packaging, agriculture, and disposable tableware.

Use of commercial synthetic filament waste to reinforce biobased poly(butylene succinate) with the aid of compatibilizers

Since poly(butylene succinate) (PBS) has low rigidity for engineering application, this research attempted to reinforce PBS with poly(ethylene terephthalate) (PET) and polyamide-6 (nylon6) filaments with the reservation of polymer toughness. Filaments were chopped to be short fibers (length of 2 mm to 4 mm) and melt compounded with PBS pellets in the weight ratio of 1 wt%, 5 wt%, and 7 wt% using a twin-screw extruder that the temperature profile was set high enough for melting only PBS matrix. Two types of compatibilizers; hexamethylene diisocyanate (HMDI) or hexamethylene diamine (HMDA) of 0.05 wt% were used to treat fiber surface. It was found that tensile modulus of PBS increased with respect to fiber concentration, which untreated PET fibers provided higher tensile modulus about 2% to 7%. Surface treatment of fibers with either HMDI or HMDA increased rigidity of the composites, while elongation at break and impact strength were also improved with respect to fiber concentration. Also, shifting in glass transition temperature of PBS by DMA indicated improved interfacial interaction, which HMDA treatment gave the best benefit for mechanical properties. Number-average molecular weight of HMDI-treated composites was closed to extruded PBS, however, those of HMDA-treated composites were reduced dramatically implying chain scission highly occurred. SEM micrographs revealed good interfacial adhesion obtained after fiber treatment. Crystallization of PBS studied by XRD showed that the crystal form was not affected by the compatibilizer.

Influence of compatibilization methods on the compatibility between asphalt and DCLR components with molecular dynamics (MD) method

This study aims to investigate the effect of compatibilization methods on the compatibility between asphalt and direct coal liquefaction residue (DCLR) components to identify the key components in DCLR and asphalt that affect their compatibility. In this article, three types of compatibilizers, including benzyl alcohol (BA), dioctyl phthalate (DOP), and BA/DOP, were selected and acted on asphalt's components and DCLR's components, respectively. The molecular models of asphalt components, asphalt components with compatibilizers, DCLR components, and DCLR components with compatibilizers were established. The compatibility between DCLR and asphalt's four components, as well as between asphalt and DCLR's three components, were evaluated by solubility parameter difference (SPD) and interaction energy (IE). The compatibility between DCLR and asphalt was analyzed by Segregation test and Scanning Electron Microscope. Results indicate that the SPD and IE values between DCLR and asphalt components declined after adding compatibilizers, which implies that the repulsion decreased and the attraction increased between asphalt components and DCLR and the compatibility between asphalt components and DCLR improved. The IE values between DCLR components and asphalt increased after adding compatibilizers, which indicates that the compatibility was reduced between DCLR components and asphalt. The SPD values between DCLR components and asphalt increased after adding the BA/DOP. The SPD values between pre-asphaltene and asphalt decreased after adding the BA and DOP. The SPD value between asphaltene in DCLR and asphalt increased after adding the BA and decreased after adding the DOP. Moreover, the storage stability and homogeneity of DCLR-modified asphalt improved after adding compatibilizers, indicating that the compatibilizers enhanced compatibility between DCLR and asphalt. Finally, comparing the results of the tests, it could be found that compatibilizers preferentially acted on the asphalt components and mainly affected the aromatics in asphalt, thereby improving the compatibility between asphalt and DCLR. The effect of BA/DOP on improving the compatibility between asphalt and DCLR was better than that of BA and DOP.

Dynamically vulcanized CNC‐reinforced thermoplastic elastomer based on PP/EPDM: Morphology and mechanical properties control via interfacial compatibilization

AbstractIn this study, dynamically vulcanized thermoplastic elastomer nanocomposites consisting of polypropylene (PP) as the thermoplastic matrix, ethylene propylene diene monomer (EPDM) rubber as the dispersed phase, and needle‐like cellulose nanocrystals (CNC) were investigated. The two polymers were melt blended in a ratio of 70/30 (PP/EPDM) and 60/40% w/w (PP/EPDM) together with CNC (2, 3, and 5 phr) and sulfur‐curing system. The potential of EPDM‐g‐MA and PP‐g‐MA's as interfacial compatibilizers for enhancing interfacial interactions between components and partitioning of CNC between the two polymer phases was examined by measuring the decrease in the size of EPDM particles. The resulting thermoplastic vulcanizates (TPV) were characterized using a melt rheometric mechanical spectrometer (RMS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and tensile tests. The inclusion of any type of interfacial compatibilizers led to enhanced tensile properties when compared to the samples lacking compatibilizers in both TPVs and TPEs in different ratios. EPDM‐g‐MA was found to be more effective for 60/40% w/w (PP/EPDM) TPVs, while PP‐g‐MA showed higher potential for 70/30% w/w TPVs. The CNC‐reinforced TPVs displayed higher melt elasticity than their unloaded counterparts. These nanocomposites also showed reduced EPDM particle size, enhanced Young modulus, and a higher degree of crystallinity.Highlights Nanocomposite thermoplastic vulcanizates (TPVs): polypropylene (PP)/ethylene propylene diene monomer (EPDM)/cellulose nanocrystals (CNC) with matrix‐dispersed morphology. Interfacial enhancement: Compared EPDM grafted maleic anhydride (EPDM‐g‐MA) and PP‐g‐MA potentials. Tensile properties: EPDM‐g‐MA is more effective in higher rubber content TPVs. Mechanical enhancements: Improved properties and Young's modulus in CNC‐filled TPVs. Diverse applications: PP/EPDM/CNC nanocomposites in auto, electrical, electronic, and packaging industries.

Influences of compatibilizer type and loading on properties of phenolic resin-crosslinked natural rubber composites filled with sepiolite

Influences of compatibilizer type and loading on properties of phenolic resin-crosslinked natural rubber composites filled with sepiolite

Fabricating super tough polylactic acid based composites by interfacial compatibilization of imidazolium polyurethane modified carbon nanotubes

The interfacial compatibilization and dispersion of carbon nanotubes (CNTs) in incompatible poly(lactic acid)/poly(butylene terephthalate adipate) (PLA/PBAT) composites are key points for evaluating the performance of the composites. To address this, a novel compatibilizer, sulfonate imidazolium polyurethane (IPU) containing PLA and poly(1,4-butylene adipate) segments modified CNTs, employed in conjunction with multi-component epoxy chain extender (ADR) to toughen synergistically PLA/PBAT composites. The thermal stability, rheological behavior, morphology, and mechanical properties of PLA/PBAT composites were performed by TGA, DSC, dynamic rheometer, SEM, tensile, and notched Izod impact measure. Moreover, the elongation at break and notched Izod impact strength of PLA5/PBAT5/4C/0.4I composites achieved 341 % and 61.8 kJ/m2 respectively, whose tensile strength was 33.7 MPa. The interfacial compatibilization and adhesion were enhanced because of the interface reaction catalyzed by IPU and the refined co-continuous phase structure. The CNTs non-covalently modified by IPU that bridged at the PBAT phase and interface transferred the stress into the matrix, prevented the development of microcracks, and absorbed impact fracture energy in the form of pull-out of the matrix, inducing shear yielding and plastic deformation. This new type of compatibilizer with modified CNTs is of great significance for realizing the high performance of PLA/PBAT composites.

Electrical and Structural Properties of HDPE/MWCNT/PE-g-MAH Nanocomposites Prepared Using Solution Mixing and Hot Compaction Two-step Approach

Background:MWCNTs tend to form agglomerates in nonpolar polymers due to their small size and large surface area. A promising approach to facilitate their dispersion within the polymeric matrix is based on employing a compatibilizer agent.Objective:The current study aimed to investigate the effect of a compatibilizer agent based on maleic anhydride grafted HDPE (PE-g-MAH) on the electrical and morphological properties of highdensity polyethylene/multi-wall carbon nanotubes nanocomposites (HDPE/MWCNT/PE-g-MAH) prepared by solution mixing and hot compaction two-step approach.Methods:A two-step approach based on solvent mixing and hot compaction was used to prepare nanocomposites of HDPE/MWCNT/PE-g-MAH with different MWCNTs and PE-g-MAH contents. The electrical, morphological, and HDPE crystalline structure properties of the nanocomposites were characterized by impedance spectroscopy, high-resolution field emission scanning electron microscopy, and X-ray diffraction, respectively.Results:The results confirm the positive role of the PE-g-MAH compatibilizer in enhancing the dispersion of the MWCNTs and, in turn, the formation of more conductive pathways at low MWCNTs content in the nanocomposites. Adding 2 wt% of the compatibilizer to the nanocomposite of 1 wt% MWCNTs increases the electrical conductivity by more than three orders of magnitude. Increasing the MWCNTs concentration by more than 1 wt% leads to a limited enhancement in conductivity of the nanocomposite prepared using 2 wt% of PE-g-MAH compatibilizer. Meanwhile, the morphological characterization revealed that the limited increase in conductivity of nanocomposites with only 1 wt% compatibilizer is related to a substantial increase in the HDPE crystallinity (from 14.8 to 43.9%) induced by the enhanced nucleating effect of the dispersed MWCNTs. The excess HDPE crystalline regions suppress the formation of effective MWCNTs conducting pathways due to their confinement into smaller inter-crystallite regions in the nanocomposite.Conclusion:Therefore, a balanced role of the compatibilizer between the dispersion of the MWCNTs and the nucleation of more HDPE crystallites has to be achieved by carefully selecting the compatibilizer type and concentration.

ВЛИЯНИЕ КОМПАТИБИЛИЗАТОРА И СКОРОСТИ ПЕРЕМЕШИВАНИЯ НА ФИЗИКО-МЕХАНИЧЕСКИЕ СВОЙСТВА СМЕСИ ПОЛИМЕРОВ НА ОСНОВЕ ПОЛИВИНИЛХЛОРИДА И ПОЛИЭТИЛЕНА

This piece of work has investigated features of deformation of polyvinyl chloride (PVC) and polyethylene (PE) polymer blends, resulted in the presence of two types of compatibilizers, and made a comparative assessment of the elastic strength characteristics of the blends versus their variations produced in the intensity of mixing components in the melt. The effect of plasticization of PVC with dioctyl phthalate was found at increased speed of stirring, expressed by a decrease in the modulus of elasticity and stress at the yield point. For mixtures with a PVC matrix in the absence of a compatibilizer, an increase in the PE content leads to a drop in stress at the yield point and elongation at break; for equal mixture compositions with intense mixing, the deformation curves show a combination of the yield zone and orientational ordering.

Effect of compatibilizer on the structure and property of polycarbonate/polypropylene alloys

AbstractPolycarbonate/Polypropylene (PC/PP) alloy is a typical thermodynamically incompatible system. In this work, ethylene‐methyl acrylate copolymer (EMA), methoxamine hydrochloride‐grafted POE (POE‐g‐MAH), ethylene‐butyl acrylate‐glycidyl methacrylate copolymer (EAY), a self‐made compatibilizer (PPM‐g‐GMA) of a mixture of glycidyl methacrylate grafted PP (PP‐g‐GMA) and glycidyl methacrylate‐grafted POE (POE‐g‐GMA) were selected as compatibilizer to prepare PC/PP alloys with the mass ratio of 65:30. Systematical studies of compatibilizer type, content and its effects on microstructure, mechanical properties, dielectric properties, dielectric properties and dynamic rheological properties have been carried out in this PC/PP alloys. The results demonstrated that all the compatibilizers in this article resulted in an effective improvement of the compatibility of PC/PP alloys, and the self‐made compatibilizer of PPM‐g‐GMA exhibited a significant improvement over the other three compatibilizers in notched izod impact strength, tensile strength, and bending strength. In addition, a relative low dielectric constants and dielectric losses under 2.5 GHz electric field could be obtained with the assistance of POE‐g‐MAH and PPM‐g‐GMA, indicating its possible application in dielectric materials.

Efficiency of interaction between hybrid fillers carbon black/lignin with various rubber-based compatibilizer, epoxidized natural rubber, and liquid butadiene rubber in NR/BR composites: Mechanical, flexibility and dynamical properties

This study reports the effect of two different types of compatibilizer, namely epoxidized natural rubber with 50 mol% of epoxide group (ENR-50) and liquid butadiene rubber (LBR-352) for carbon black/lignin-filled natural rubber/polybutadiene rubber (NR/BR) composites in the range of 5–15 parts per hundred rubber (phr). The presence of ENR at concentrations up to 10 phr in carbon black/lignin-filled NR/BR composites reduced cure and scorch time by 33.7% and 21.1% respectively, compared to composites without ENR. This contributed to a better dispersion of the filler and an increase of the 300% modulus by 28.1%. Scanning electron microscopy results (SEM) showed better interaction between carbon black/lignin-filled NR/BR with ENR. Meanwhile, the composites with LBR showed the lowest filler-filler interaction, indicated by a decrease in storage modulus with an increase in strain in the filled compound i.e., Payne effect. Moreover, the utilization of LBR was increased by 168.8% compared to 18.3% with the addition of ENR. It can be concluded that the presence of ENR can enhance the mechanical, flexibility and dynamical properties, while the use of LBR can improve the process-ability and flexibility of rubber composites.

A review on graft compatibilizer for thermoplastic elastomer blend

A biodegradable thermoplastic elastomer (TPE) blend is developed by blending poly (lactic acid) (PLA) and natural rubber (NR) or epoxidized natural rubber (ENR) and it is a sustainable substitution in recent years for synthetic polymers. PLA is high in mechanical strength and compostable, but it is highly stiff and brittle. The incorporation of NR or ENR to PLA increases the impact strength and toughness of PLA. However, the disparity in polarity between PLA and elastomer phase like NR and ENR results in TPE blend being incompatible. Hence, compatibilization is essential to improve its polarity and develop interactions. Compatibilizer that composed of two different polymer is known is graft compatibilizer with the aid of grafting agent. The graft compatibilizers are divided into two categories. The first type is made up of one polymer and grafting agent and, the other one is composed of two polymer groups and grafting agent. These two types of graft compatibilizer can be prepared via two different method such as direct melt blending and solution. Apart from this, the TPE blend is produced via the melt blending technique with mixing machines such as internal mixer and extruder. This article has reviewed the preparation of the graft compatibilizer and blending technique of TPE. Based on the findings, the graft compatibilizers has a significant role in improving miscibility and compatibility across blend composed of different phase.

Dynamic and static mechanical properties of PP/EVA blend nanocomposites: Effects of type of masterbatch preparation technique and nature of compatibilizer

Polypropylene (PP)/poly (ethylene-co-vinyl acetate) (EVA) nanocomposites were prepared with use of 3 wt% of organophilic halloysite nanotubes (Org-HNTs) and 3 types of compatibilizers in two steps. First, masterbatchs of EVA and the compatibilizers with the Org-HNT were prepared by two different preparation techniques; melt masterbatch (MM) and solution masterbatch (SM). The masterbatchs were then melt compounded with PP in the second step. Special attention was paid to effects of nature of compatibilizer and masterbatch preparation technique on morphology-mechanical property relationship for the composites. Poly(ethylene-vinyl acetate-carbon monoxide) (EVACO) and maleic anhydride grafted EVA (EVA-g-MA) were used as EVA-based compatibilizers which gave a homogeneous distribution of the nanotubes in the matrix and at the matrix-elastomer interphase as compared to maleic anhydride grafted PP (PP-g-MA). The both masterbatch techniques provided a core-shell morphology composed of nanotubes as core surrounded with elastomer phase as a shell, which led to higher toughness and impact resistance for the composites. Particularly, the EVACO compatibilizer provided the highest toughness, tensile modulus and impact resistance for 3% Org-HNT loaded nanocomposite produced with the SM technique. The same nanocomposite was found to act as an effective damper with an optimum modulus in a broad range of temperature and show a relatively higher creep resistance than the counterpart produced with the MMT technique. It also exhibited 66% higher scratch resistance compared to the PP/EVA blend, which makes it advantageous for the visible parts in automotive applications.

Improved Toughness of Polylactide by Binary Blends with Polycarbonate with Glycidyl and Maleic Anhydride‐Based Compatibilizers

AbstractThis work reports on the development of polylactide (PLA) and polycarbonate (PC) blends with different compatibilizers with enhanced toughness. Since both polymers are immiscible, two types of compatibilizers are tested: petrochemical‐based copolymers Xibond 160 and Xibond 920 with maleic anhydride and epoxy groups, respectively, and natural‐based compatibilizers with the same functionalities, namely maleinized linseed oil (MLO) and, epoxidized linseed oil (ELO). Mechanical, thermal, and morphological characterization shows better properties for the PLA/PC (80/20 wt%) blends with chemically modified natural oils (ELO and MLO). The addition of 5 phr (parts per hundred resin) of MLO gives the maximum values for impact strength and elongation at break. Moreover, the glass transition temperature (Tg) slightly decreases with the addition of natural compatibilizers, thus showing some plasticization effect. Petroleum‐derived compatibilizers give interesting results regarding tensile strength and stiffness without plasticization. PLA/PC blends show higher thermal stability than neat PLA, regardless of the compatibilizer used, since PC is much more thermally stable than PLA. The obtained results indicate that both petroleum‐based and natural‐derived compatibilizers positively contribute to enhance the properties of the binary PLA/PC blends. Nevertheless, the results with MLO suggest this is an interesting biobased solution to provide increased toughness to PLA/PC blends.

The effect of different compatibilizers on the properties of prepared poly(lactic acid)/polyurethane nanofibers by electrospinning

In this study, the poly(lactic acid) (PLA)/polyurethane (PU) nonwoven mats have been successfully fabricated by electrospinning from PLA/PU (50:50 w/w) blended solutions with/without compatibilizer. The influence of the compatibilizers which are called POSS Amic Acid Isobutyl (AAI), Tetra Silanol Phenyl POSS (TSP) and Joncryl (JO) on the characteristic properties of PLA/PU nanofibers has been investigated. The types of compatibilizer used in this paper were studied for the first time in the literature for PLA/PU blend nanofibers. The nanofibers were characterized with scanning electron microscope, fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, contact angle test, and mechanical analysis. The electrospun mat which has the smoothest fiber surfaces, thinnest fiber diameter with 812 nm and a superhydrophobic surface structure with an angle of 154° was obtained by using AAI. The fabricated nanofiber by using JO has been seen having the highest strength value with 3.5 MPa and the highest crystallinity ratio with 20.1%. The highest elongation value with 51.9% was obtained for the nanofiber by using TSP. When the 5% weight loss temperature value of all PLA/PU nanofibers was compared, it was noted that the JO added nanofiber has the highest temperature durability with 292.16 °C. Also, the Tm value of all PLA/PU nanofibers has been resulted at about 155 °C like of pure PLA nanofiber. It is expected that thin and flexible biodegradable PLA/PU nanofibers with good physical and mechanical properties can be used in areas such as water repellent coating material, food packaging.

Bio-based polyhydroxyalkanoates blends and composites

Abstract Polyhydroxyalkanoates (PHAs) are linear semicrystalline polyesters produced naturally by a wide range of microorganisms for carbon and energy storage. PHAs can be used as replacements for petroleum-based polyethylene (PE) and polypropylene (PP) in many industrial applications due to their biodegradability, excellent barrier, mechanical, and thermal properties. The overall industrial applications of PHAs are still very limited due to the high production cost and high stiffness and brittleness. Therefore, new novel cost-effective production method must be considered for the new generation of PHAs. One approach is based on using different type feedstocks and biowastes including food byproducts and industrial and manufacturing wastes, can lead to more competitive and cost-effective PHAs products. Modification of PHAs with different function groups such as carboxylic, hydroxyl, amine, epoxy, etc. is also a relatively new approach to create new functional materials with different industrial applications. In addition, blending PHA with biodegradable materials such as polylactide (PLA), poly(ε-caprolactone) (PCL), starch, and distiller’s dried grains with solubles (DDGS) is another approach to address the drawbacks of PHAs and will be summarized in this chapter. A series of compatibilizers with different architectures were successfully synthesized and used to improve the compatibility and interfacial adhesion between PHAs and PCL. Finer morphology and significantly improvement in the mechanical properties of PHA/PCL blends were observed with a certain type of block compatibilizer. In addition, the improvement in the blend morphology and mechanical properties were found to be strongly influenced by the compatibilizer architecture.

The effect of epoxidized vegetable oil and phthalic anhydride as compatibilizers on properties of rubber seed shell/polypropylene composites

Numerous adverse effects are reported from excessive usage of synthetic polyolefins including major environmental concerns. Since then, the development of natural-based polymer composites is escalating, to replace the versatile conventional plastics that possess excellent mechanical and thermal properties. Rubber seed shell (RSS) is a novel and abundant natural-based substituent that is highly composed of hemicellulose and cellulose. In this work, we reported on the performance of RSS-filled polypropylene composites added with two different types of compatibilizers: epoxidized vegetable oil (EVO) and phthalic anhydride (PA). The composites were produced using a Haake internal mixer and a compression molding. The tensile, flexural, and impact properties of the composites were analyzed. Later, we investigated the thermal stability and water absorptivity of the composites. The mechanical, thermal, and water absorption properties of the RSS-filled composites deteriorated with increasing RSS loadings. For both EVO and PA-compatibilized systems, the mechanical properties were enhanced except for the elongation-at-break of the composites. PA-compatibilized composites recorded better thermal stability and water absorption resistance under ambient conditions compared to RSS composites with EVO. The qualitative structural evidence of the composites enhanced properties and deterioration were observed using a Zeiss Supra scanning electron microscope. As a novel natural filler, RSS has adequately proven its practicability in manufacturing environmentally friendly natural composites with acceptable mechanical and thermal properties.

Formulation of a new polymer based on PP and PLA

The mixtures containing polypropylene are used in the industrial sector as material for bags, chairs, household items, and can even be used in cell phone batteries. The interest in creating this material is due to its low density compared to more common materials such as iron and ceramic, in addition to its good corrosion resistance and reasonable mechanical properties in environments without high temperature and pressure. In order to diversify the mechanical and viscous properties, different types of polymers were used, such as lactic polyacid, which has beneficial properties for recycling such as degradation. It is a challenge to control the right proportion and use additives and plasticizers to control the desired properties. The methods used to measure the properties of polypropylene and polylactic acid mixtures with different types of additives, compatibilizers and plasticizers were DMA, TGA, tensile, DSC and rheology tests following ASTM standards. The results were promising, observing different mechanical and viscosity properties for the PP/PLA/PP-g-MA/D mixture in different proportions. Thus concluding that the different products have varied application in the industry.

Evaluation of the adhesion characteristics of material composition for polyphosphoric acid and SBS modified bitumen based on surface free energy theory

Styrene-butadiene-styrene (SBS) modified bitumen is widely applied to the construction of high-grade pavement because of its good pavement properties. However, with the rising price of SBS polymer, SBS modified bitumen is more expensive. By adding the cheap modifier polyphosphoric acid (PPA) to bitumen and compounding with SBS, the production price of SBS modified bitumen is obviously reduced, and the miscibility between SBS and bitumen is promoted. In this study, the effect of base bitumen type, PPA type and raw materials content on the adhesion performance of polyphosphoric acid compounded SBS (PPA/SBS) modified bitumen was evaluated quantitatively using the contact angle test and surface free energy method. Three different bituminous materials, two types of PPA, SBS, stabilizer, compatibilizer and dibutyl phthalate (DBP) were used as raw materials to prepare PPA/SBS modified bitumen. The results indicate that PPA improves the adhesion of PPA/SBS modified bitumen, but with an increase in PPA content above a certain value, the cohesion work, adhesion work and compatibility ratio of PPA/SBS modified bitumen decrease gradually and the peeling work increases gradually. In the blending process of PPA and SBS, changes in adhesion performance depend mainly on the base bitumen type, PPA type and raw material content. Using SK 90# base bitumen; 105% PPA; and PPA, DBP, extraction oil, and SBS contents of 0.5%, 1%, 1.5%, and 3.5%, respectively, the water damage resistance of PPA/SBS modified bitumen is considerably improved.

Valorization of waste polyethylene by blending with ethylene‐vinylacetate and incorporating a new type of compatibilizer

AbstractNowadays polyethylene is one of the polymers produced in the greatest volume and the amount of generated waste high‐density polyethylene (w‐HDPE) is significant as well. Valorization and recycling of w‐HDPE can be realized by blending with different types of polymers and/or elastomers for example, ethylene‐vinyl acetate (EVA). For the purpose of boosting of interfacial interactions between these two polymers experimental olefin‐maleic‐anhydride based additives have been incorporated into the blends after optimization of the processing temperature. Impact and tensile tests have been carried out in our research work besides microscopy measurements and investigation of the effects of additive structure by FT‐IR and rheology. At higher processing temperature (220°C) both tensile properties and Charpy impact strength were increased, latter one improved by 245% measured at 5°C while elongation at break enhanced by 182% with incorporation of some experimental additives compared to the neat 70/30 w‐HDPE/EVA. Changes in the hydrocarbon molecular chains of experimentally compatibilized blends were observed based on FT‐IR results and rheological measurements. It can be concluded that one of the most basic notions of sustainability, the 4R's (reduce, recycle, reuse, recover) has been satisfied in a successful way.

Nonisothermal Crystallization Kinetics of Polylactic Acid under the Influence of Polyolefin Elastomers

Crystallization kinetics of various blends of poly(lactic acid) (PLA)/polyolefin elastomer (POE) was studied through nonisothermal experimental investigations and theoretical approaches. The PLA/POE blends were prepared in a melt mixing process by using two types of POEs and compatibilizers. The rubber phases used were adopted on the basis of polyethylene (PE) and polypropylene (PP) type olefin elastomers. The effects of two kinds of compatibilizers containing ethylene vinyl acetate copolymer (EVA) and ethylene acrylic ester-glycidyl methacrylate terpolymer (EGMA) on the morphology and various parameters of crystallization of PLA were investigated using scanning electron microscopy (SEM) and differential scanning calorimeter (DSC) measurements, respectively. The morphology investigations on PLA blends containing PP based olefin elastomers showed that the introduction of EGMA compatibilizer into the matrix led to a more than 100% reduction in the size of the rubber droplets. The experimental measurements of crystallization behavior of various PLA/POE blends showed that the POEs and compatibilizers could cause a fall in the initial crystallization temperature more than 13 °C. The theoretical approaches used for studying the kinetics of crystallization of PLA in the presence of various POEs and compatibilizers indicated a decrease in the crystallinity of PLA and a 64% reduction in the activation energy compared to the neat PLA. The results suggest that the largest variation in the crystallization kinetic parameters of PLA was resulted from the PP based olefin elastomer and EGMA compatibilizer.