Compatibilizer Agent Research Articles

Fatty alcohols as sustainable compatibilizer agents for the compound of natural rubber/silica: The curing, rubberiness and tensile strength behaviours

Fatty alcohols are derived from palm oil production and, stearyl and lauryl alcohols are examples of them. The stearyl and lauryl alcohols have the potential to be used as rubber additives for the compounding and vulcanizing processes. These materials are relatively new as rubber additives and, they were added into silica-filled natural rubber (NR) compound. The aim of using them is to increase the grade of silica dispersion inside the NR matrix. Initially, the NR was filled by (precipitate) silica at 30 parts per hundred of NR, whilst the fatty alcohols were added into the silica-filled NR with variable concentrations from 1 to 4 phr, separately. The compounds of NR/silica/stearyl alcohol and NR/silica/lauryl alcohol have been vulcanised at 150 °C by implementing a semi-efficient rubber composition. From the vulcanization behaviour, it was observed that both fatty alcohols have the role of compatibilizer and plasticising agents for the compound of NR/silica. Those fatty alcohols decreased the viscousness but increased the curing rate index (CRI). The more concentration of fatty alcohols was supplied, the less viscousness and the higher the CRI. Those fatty alcohols also shifted the crosslinking level and tensile strength. It also observed that the break elongation or rubberiness has been shifted up. Tensile strength has been shifted to a maximal value with a 2 phr of stearyl alcohol or 3 phr of lauryl alcohol addition.

The effect of physical compatibilization and dynamic vulcanization on the properties of thermoplastic vulcanizates derived from polypropylene and natural rubber blends

This interesting study investigated the effect of Maleic Anhydride-grafted-Polypropylene/Epoxidized Natural Rubber (PP-g-MA/ENR) as a compatibilizing agent (CA) on the properties of a 30/70 Polypropylene/Natural Rubber PP/NR blends. The effect of dynamic vulcanization with sulfur-donors (i.e.: Tetramethyl thiuram disulfide (TMTD) and 4,4 Dithiodimorpholine (DTDM)) which were used as vulcanizing agents was also reported. Several formulations of TPVs with different concentrations of CA (from 5 to 15 phr) were prepared by mixing in the molten state using a Haake Rheocord 90. The structural analysis of dual compatibilizer was examined by FTIR spectroscopy. The rheological behavior was examined using Haake Rheocord 90. The mechanical properties were determined by the tensile measurements. The dynamic mechanical thermal properties were investigated by DMA. A morphological examination was conducted using SEM Microscopy, respectively. FTIR analysis confirmed reactions between the MA group in PP-g-MA and the epoxy groups in ENR, resulting in ENR-grafted PP with an ester and acid-based linkage. The Haake plastograms revealed a proportional increase in the final mixing torque value with the increasing content of CA. The mechanical results exhibited higher values in terms of tensile strength and Young’s modulus for the TPVs containing CA compared to un-compatibilized ones. The compatibilized TPV blends exhibited a noteworthy increase in storage modulus and a notable decrease in loss tangent values with the CA concentration increased. Furthermore, the TPVs show two distinct-phase morphologies. That is, the TPV with CA showed the presence of smaller vulcanized rubber particles dispersed within the PP matrix, a phenomenon that becomes more pronounced with higher CA contents.

Enhancement of the rheological, dynamic mechanical, and morphological properties of thermoplastic natural rubber based on NR/PP blends using ENR/PP-g-MA as a compatibilizer

This study investigates the effects of incorporating a 50/50 blend of Epoxidized Natural Rubber/Polypropylene-grafted maleic anhydride (ENR/PP-g-MA) as a compatibilizing agent (CA) for a 70/30 Natural Rubber/Polypropylene (NR/PP) thermoplastic elastomer (TPE) on the technical properties such as structural analysis, rheological, dynamic mechanical and morphological properties. Formulations with varying CA concentrations (5 to 15 phr) were prepared using a Brabender plasticorder at 180°C for 10 min. The structural analysis was examined by Fourier transform infrared spectroscopy (FTIR), and proton nuclear magnetic resonance (1H-NMR). The rheological behavior was examined using a Rubber Process Analyser (RPA). The dynamic mechanical properties were investigated by DMA. Atomic Force Microscopy (AFM) was used for the morphological examination. FTIR analysis confirmed reactions between the MA group in PP-g-MA and the epoxy groups in ENR, resulting in ENR-grafted PP with an ester and acid-based linkage. This reaction was evident during compatibilizer preparation. RPA results showed increased viscosity for both types of CAs compared to their individual values, confirming crosslinking reactions. Higher CA concentrations led to elevated viscosity and storage modulus. DMA results indicated that the compatibilization led to a significant enhancement in the storage modulus of the blends. Moreover, an increase in the glass transition temperatures (Tg) of the blends was produced. AFM examination revealed a more homogenous distribution of the dispersed PP phase for the CA-containing blends compared to the control NR/PP system.

Renewable Compatibilizing Agent for Silica Reinforced Natural Rubber

The main problem in utilizing silica as an alternative reinforcing filler for natural rubber (NR) compounds is a weak rubber-filler interaction and poor filler distribution due to their incompatibility feature. The particles of silica have a strong tendency to filler interactions which leads to form silica agglomeration. To solve this drawback, this work has utilized ethanolamine-modified palm stearin (EMPS) as a renewable compatibilizer agent to improve NR-silica compatibility. The EMPS was prepared by a typical chemical reaction between ethanolamine and refined bleach-deodorized palm stearin (a byproduct of cooking oil production) on a laboratory scale. The influence of the EMPS on the improvement of rubber-filler interaction was investigated by studying the processing characteristics and the tensile properties of silica-reinforced NR compound (silica content was fixed at 30 phr). Compared to the silica-reinforced NR with no EMPS, it was found that EMPS caused a greater coefficient of vulcanization, tensile strength, and reinforcement effect for the silica-reinforced NR. It was due to an active reaction between silanol groups of silica with EMPS which increased the NR-silica compatibility, and the Fourier Transform Infra-Red (FTIR) analysis has confirmed the typical reaction.

Theoretical and experimental investigation of the compatibilization agent contribution to the interactions of polymer blend (PP/LDPE): Thermal, morphological, and DFT insights

In this research, we looked at the impact of (styrene-ethylene/butylene-styrene) SEBS 5 % wt and (maleic anhydride grafted SEBS) SEBS-g-MA 5 % wt as compatibilizer agents of polypropylene (PP)/low-density polyethylene (LDPE) blends. Compression molding was used after mixing the melts in a Brabender internal mixer to create the blends. Scanner electron microscopy (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the structural and surface behaviors of the blends and their morphology. FTIR analysis showed a weak and broad absorption peak at 1650 cm−1 for PP, LDPE and their blend, which signals the presence of carbonyl groups, and therefore oxidation of the blend. Upon addition of SEBS (styrene ethylene/butylene styrene) and SEBS-g-MA (SEBS grafted with maleic anhydride), the absorption of the carbonyl group decreases, so the peak at 1650 cm−1 becomes smaller. SEM analysis showed an improvement in the morphology and interfacial adhesion of the mixtures with the use of SEBS and SEBS-g-MA. These results suggest that the use of compatibilizers can lead to improved properties for PP/LDPE blends in various applications. Molecular modeling was also used to infer the effects of the compatibilizing agent on the properties of PP-LDPE blends. According to molecular dynamics simulations, the inclusion of SEBS dramatically increases the binding interaction energies for the 3PP/3PE and 3PP-3PE-1SEBS-g-MA systems, going from 440 kcal/mol to 880 kcal/mol, respectively. Density functional theory calculations further confirm the compatibilization role of SEBS-g-MA on the blend. In particular, Quantum molecular descriptors and the density of states demonstrate SEBS-g-MA's involvement as an intermediate in promoting PP and LDPE compatibility. Overall, our results suggest that SEBS-g-MA is a potential PP-LDPE compatibilizer.

Evaluation of Thermal Decomposition Kinetics of Poly (Lactic Acid)/Ethylene Elastomer (EE) Blends.

The influences of ethylene-based elastomer (EE) and the compatibilizer agent ethylene-butyl acrylate-glycidyl methacrylate (EBAGMA) on the thermal degradation of PLA/EE blends were evaluated by the thermal degradation kinetics and thermodynamic parameters using thermogravimetry. The presence of EE and EBAGMA synergistically improved the PLA thermal stability. The temperature of 10% of mass loss (T10%) of PLA was around 365 °C, while in the compatibilized PLA/EE blend, this property increased to 370 °C. The PLA average activation energy (Ea¯) reduced in the PLA/EE blend (from 96 kJ/mol to 78 kJ/mol), while the presence of EBAGMA in the PLA/EE blend increased the Ea¯ due to a better blend compatibilization. The solid-state thermal degradation of the PLA and PLA/EE blends was classified as a D-type degradation mechanism. In general, the addition of EE increased the thermodynamic parameters when compared to PLA and the compatibilized blend due to the increase in the collision rate between the components over the thermal decomposition.

Deformation kinetics of single-fiber polypropylene composites: Adhesion improvement at the expense of toughness

Despite the maturity of the technology, processing of fiber-reinforced thermoplastic materials remains challenging, and difficulties in processability often result in material formulations with high modulus and strength, yet rather poor ductility compared to the pure polymer matrix. To gain fundamental insight into the deformation mechanisms present in such materials, the complexity of the system is step-wise increased; first, the effect of the most commonly applied adhesion enhancement, the addition of MAH-g-PP compatibilizer, on the bulk properties is assessed. The small-strain tensile properties, i.e., modulus and yield stress, appear to be only marginally affected by the addition of such compatibilization agent, however, the strain-at-break is strongly reduced, even before the addition of the fiber reinforcement. Subsequently, using in-situ X-ray characterization methods upon tensile deformation, the time evolution of crystal structure and lamellar morphology is determined, and at first glance the compatibilizer addition appears to better preserve the crystalline structure. The onset of local failure (cavitation) is quantified at the interface of a single glass fiber. By increasing the adhesive interaction between fiber and matrix the stress concentration at the interface is increased, leading to an acceleration in void formation followed by unstable growth, which in turn strongly embrittles the composite. By the addition of various selective nucleating agents, it is demonstrated that the role of local phase composition and morphology on the deformation kinetics and subsequent failure mechanisms is much more pronounced than the increased adhesion between fiber and matrix by compatibilization or sizing effects. These findings may specify a new route towards tougher fiber-reinforced composites with reduced complexity in the material formulation.

Mechanical recycling of expanded polystyrene and tire rubber waste as compatibilized and toughened blends

AbstractPackaging represents a significant source of all polymer waste produced in the world. Thus, improving recycling methods is essential to achieve an environmentally sustainable condition since the volume of produced polymer and of related waste has grown. Expanded polystyrene (EPS) foam is a thermoplastic with important performance of properties such as thermal isolation and absorption of mechanical energy that allow large application in packaging and other segments. However, the EPS recycling is a challenger due to its low density and poor properties. The rubber incorporation to the recycled EPS is an alternative for the toughening of the polymer matrix as well as improving its mechanical properties. In present study, EPS waste from electric and electronic products packaging was treated by three distinct methods for polymer densification and after it was thermo‐mechanically processed by extrusion with variable content of ground tire rubber (GTR) and compatibilizer agent styrene‐butadiene‐styrene (SBS) copolymer to produce compatibilized and toughened PS/rubber blends. Mechanical, thermal and rheological properties of materials were evaluated by different analyses. The incorporation of rubber to the recycled EPS has significantly improved the mechanical properties of the material and the presence of the SBS agent was effective to compatibilize the PS/rubber blends. Therefore, the preparation of compatibilized PS/rubber blends showed to be a way to the mechanical recycling of EPS and rubber tires waste.

Development of composites based on a blend of recycled HDPE/post-consumer PET and bentonite clay

The recycling process is the best way to manage waste polymers. From an economic standpoint, more investigation is needed of the whole recycling process to enhance the competitiveness in these systems. A first step is improved interaction and interfacial adhesion of blends. Polyethylene (PE) and polyethylene terephthalate (PET) are incompatible polymers, so their blends in general have poor properties. Compatibilization is thus a necessary step to obtain blends with good mechanical and barrier properties. In this work, blends of recycled (high density polyethylene) (HDPE) and post-consumer PET, with organophilic bentonite clay acting as compatibilization agent at the interface of the two polymers, were obtained. The proportions of HDPE/PET/bentonite (0, 5, 10 and 15% weight percentage of bentonite) were processed by extrusion. The processed materials were characterized regarding density (ASTM D792-13), melt flow index (MFI, ASTM D1238-13), hardness (ASTM D2240–10), infrared absorption spectroscopy (FTIR), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results indicated the occurrence of some compatibilization.

Utilization of Indonesian seaweed in polyethylene-based composite with coconut husk powder as bio-compatibilizer

The addition bio-based materials into plastic is expected to produce composites that can be decompose in a shorter time compared to petroleum-based plastics. Combining hydrophobic-high density polyethylene (HDPE), with a hydrophilic-biobased material, is challenging and requires a compatibilizer agent to produce good performance bio-composite. In this study, Halymenia sp. or Gracilaria sp. seaweed was utilized as filler in HDPE based composite by 20% of total weight, and coconut husk powder that varied at 0%, 1%, 5%, and 10% was used as bio-compatibilizer. The materials were mixed in the rheomixer (rotor rotating speed of 80 rpm, at 140 °C for 5 min). The addition of 1% coconut husk powder can improve the modulus of elasticity of HDPE-Halymenia extract and HDPE-Gracilaria residue by 21.43% and 55.71%, respectively, compare to pure HDPE. Furthermore, the crystallinity index of Halymenia extract with the addition of 1% coconut husk powder was the highest (50.40%) among other HDPE-Halymenia extract composites in this study.

Effect of antibacterial and compatibilizer agents on properties of low-density polyethylene composites

In this study, antibacterial low-density polyethylene (LDPE) composites were prepared using a silver-based antibacterial agent (Ag agent) and compatibilizer (linear low-density polyethylene-g-maleic anhydride (LLDPE-g-MA)), and their thermal, mechanical, and antibacterial properties were examined. The crystallization temperatures of the compatibilizer/antibacterial composites were higher than those of the composites prepared without a compatibilizer. LDPE is a crystalline material, and the addition of LLDPE-g-MA reduced the PE content and enthalpy of the composite and improved the dispersibility of the Ag agent between the substrates. The antibacterial activity test revealed that the addition of the Ag agent and compatibilizer to LDPE composites enhanced their antibacterial effects.

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.

Grafting of maleic anhydride on poly(lactic acid)/hydroxyapatite composites augments their ability to support osteogenic differentiation of human mesenchymal stem cells.

Implantation of bone substitutes is the treatment of choice for bone defects exceeding a critical size, when self-healing becomes impossible. The use of 3D printing techniques allows the construction of scaffolds with customized properties. However, there is a lack of suitable materials for bone replacement. In this study, maleic anhydride-grafted poly (lactic acid) (MAPLA) was investigated as a potential compatibilizer agent for 3D-printed polylactic acid (PLA)/hydroxyapatite (HA) composites, in order to enhance the physicochemical and biological properties of the scaffolds. The grafting process was performed by reactive processing in a torque rheometer, with the evaluation of the use of different concentrations of maleic anhydride (MA). The success of the grafting reaction was confirmed by titration of acid groups and spectroscopic analyses, indicating the presence of succinic anhydride groups on the PLA chain. Morphological analysis of the PLA/HA 3D scaffolds, using SEM, revealed that the use of the compatibilizer resulted in a structure free from voids and holes. The compatibilization also increased the degradation process. On the other hand, TGA and DSC analyses revealed that the use of a compatibilizer had little effect on the thermal properties of the composite. Most importantly, the samples with compatibilizer were demonstrated to have a minimal cytotoxic effect on human mesenchymal stem cells (MSCs), promoting the osteogenic differentiation of these cells in a medium without the addition of classical osteogenic factors. Therefore, the grafting of PLA/HA composites improved their physicochemical and biological properties, especially the induction of MSC osteogenic differentiation, demonstrating the potential of these scaffolds for bone tissue replacement.

Effect of Recycled Graphite as an Antistatic Agent on the Mechanical, Thermal, and Electrical Properties of Poly(Trimethylene Terephthalate)

AbstractRecycling graphite waste can bring economic offers and environmental protection. This study investigates the use of recycled graphite (RG) from aerospace sector components as an antistatic agent. Mechanical, thermal, and electrical properties of poly(trimethylene terephthalate) (PTT)/RG composites are investigated to develop a composite with suitable characteristics for antistatic packaging applications. First, the RG is purified by thermal treatment to eliminate any impurities and residual oils, and the purified recycled graphite (PRG) is characterized by thermogravimetric analysis (TGA), Fourier‐transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), and scanning electron microscopy (SEM). Then, the PRG is used as an antistatic filler and added in different concentrations in the PTT matrix by melt processing using an extruder. The compatibilizer agent maleic anhydride grafted PTT (PTT‐g‐MA) is added to the system to improve filler interaction and distribution into the matrix. Thus, the addition of different contents of PRG (1, 3, 5, 10, and 20 wt%) with and without compatibilizer agent (2:1, PRG:PTT‐g‐MA) in the PTT matrix is investigated by thermal, electrical, and mechanical properties. The addition of 10 wt% of PRG in the PTT decreases eight decades in the electrical resistivity compared to neat PTT, being suitable for application as antistatic packaging.

Pembuatan komposit dari serat tandan kosong kelapa sawit dengan matrik polipropilen serta penambahan grafting agent PP-g-MA

Indonesia is one of the largest producers of palm oil in the world, and possibly one of the largest generators of empty palm bunch wastes. Researchers have studied these wastes to be utilized as a fuel alternative, additives to concrete, fertilizers, and other uses. However, the amount of empty palm bunch wastes seemed to stay in a high number. Another use of empty bunch conducted in this research was as fillers on polymer composites due to its high content of cellulose The aim of this research is to obtain a new source of material based on natural palm oil waste as a substitute natural minerals that is limited at nature.The methode used was incorporating empty bunch with hot melt mixing, using two roll mills and adding pp-g-ma as a compatibilizer agent. After composites were formed, characterizations were conducted by analyzing micro-structures using Scanning Electron Microscope (SEM) and testing the mechanical properties with tensile strength and elongation. Results of this study showed that the sizes of fibers of the palm bunch greatly affected the results of characterizations. Effects were also shown with effectivity of compatibilizer concentrations and mixing methods

Influence of ammonium polyphosphate‐modified polypropylene on flammability characteristics of polypropylene keratin and chitosan sustainable composites

AbstractThe combination of keratin fibers (KF), obtained from poultry feathers, with chitosan (Ch) are employed in polypropylene (PP) composites to enhance the flame‐retardant (FR) properties. The combined effect of each additive and the use of functionalized PP with ammonium polyphosphate (PP‐gAPP) as a compatibilizer, compared with PP‐gMA, on composite FR properties was analyzed. This compatibilizer was prepared by melt reaction of maleic anhydride grafted PP (PP‐gMA) with ammonium polyphosphate (APP). The grafting of APP was characterized by FTIR, XRD, and NMR. PP/KF/Ch composites using PP‐gAPP as compatibilizer were characterized by TGA, mechanical properties, and fire‐retardant tests such as UL‐94 (HB), limiting oxygen index (LOI), and cone calorimeter evaluations. These tests demonstrated the enhancement in fire‐retardant characteristics obtained by using PP‐gAPP as a compatibilizer agent compared with PP‐gMA. The combination of the additives (KF and Ch) with PP‐gAPP as compatibilizer in PP, increases the modulus and tensile strength and significantly improves the LOI and reduces the peak heat release rate during cone calorimetry tests with better thermal stability and a noticeable reduction in horizontal burning rate. Most important, the results indicated that the combination of these additives produce similar flame retardancy than a reference sample with high magnesium hydroxide loading. These composites are a promising way to meet the growing demand for high‐performance materials with FR characteristics using bio‐fire retardant additives such as KF and Ch, in sustainable and environmentally friendly composites.

Effect of alkali surface treatment and compatibilizer agent on tensile and morphological properties of date palm fibers‐based high density polyethylene biocomposites

AbstractThe objective of the present study is to develop an environment friendly alternative material based on available and local bio‐source from the wastes of Algerian date palm trees, date palm twigs fiber (DPF) was selected as an effective reinforcing material for high density polyethylene (HDPE) biocomposite. Two types of treatments have been used including sodium hydroxide (NaOH) treatment to obtain DPF1 followed by potassium permanganate (KMnO4) treatment to obtain DPF2 for aim to improve fiber‐matrix compatibility, HDPE biocomposite reinforced with different ratios of DPF1 and DPF2 varying from 10 to 30 wt% were elaborated, characterized, and compared to select the preferred treatment and percent of DPF which can be used with high properties. The results obtained indicates that the incorporating of 30 wt% of DPF2 in HDPE biocomposite led to an improve in the mechanical and morphological properties. In fact, the improvement in interfacial properties improve ultimate biocomposite performance, and thus qualified its use in different industrial application. The maleic anhydride grafted high‐density polyethylene (HDPE‐g‐MA) was incorporated as a coupling agent to the reinforced biocomposite of 30 wt% DPF2/HDPE with two different loading (7 and 10 wt%), Also, the treatments were seen to enhance the tensile strength and elastic modulus. Additionally, the biocomposites observation by scanning electron microscopy (SEM) and atomic force microscopy (AFM) revealed more intimate contact between the fibers and HDEP matrix after surface modification. The results suggested that the successful sample with best characteristics which can be advised is 30 wt% DPF2/HDPE/10 wt% HDPE‐g‐MA, that offer their use in many applications particularly in the automotive industry.

Thermal and Rheological Characterization of Recycled PET/Virgin HDPE Blend Compatibilized with PE-g-MA and an Epoxy Chain Extender.

In this work, recycled poly(ethylene terephthalate) (PETR) was blended with virgin high-density polyethylene (HDPE) in an internal mixer in an attempt to obtain a material with improved properties. A compatibilizer (PE-g-MA) and a chain extender (Joncryl) were added to the PETR/HDPE blend and the rheological and thermal properties of the modified and unmodified blends as well as those of virgin PET with virgin HDPE (PETV/HDPE). All the blends were characterized by torque rheometry, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The data obtained indicate that the incorporation of either the chain extender or the compatibilizer agent led to increases in torque (and hence in viscosity) of the blend compared to that of the neat polymers. The joint incorporation of the chain extender and compatibilizer further increased the viscosity of the systems. Their effect on the crystallinity parameters of HDPE was minimal, but they reduced the crystallinity and crystallization temperature of virgin and recycled PET in the blends. The thermal stability of the PETR/HDPE blend was similar to that of the PETV/HDPE blend, and it was not affected by the incorporation of the chain extender and/or compatibilizer.

Enhancement of adhesion properties between cement matrices and saturated substrates with asphalt mat by compatibilizing agents

Maintenance of construction elements is a necessary intervention action; preventive and corrective, which directly interferes with durability, lifetime performance. The same goes for reservoirs, where the waterproofing system makes it watertight, guaranteeing the potability of the stored water, an essential situation for the ideal conditions of an enterprise. The old projects have, mainly, waterproofing with asphalt blanket in their reservoirs, when entering the maintenance schedule to revitalize the waterproofing system, the companies adopt the application of cementitious waterproofing agents, such as Polymeric Mortar and Acrylic Polymer Membrane with cement, where they have chemical incompatibility that prevents good adherence to the substrate saturated with asphalt emulsion and asphalt mat traces. This work aims to determine the best method for creating bonding bridges between the standardized substrate covered with asphalt mat and the cementitious composite added with four different types of compatibilization agents applied in cement: sand: additive: water as 1:1:0.5:0 and 1:1:0.25:0.25. The additives are Epoxy primer for wet bases; Styrene-Butadiene emulsion (SBR); Vinyl copolymer and Acrylic-based emulsion. After curing, to guarantee the perforation of all applied layers in an integral and standardized way, three holes with an exact internal diameter were perforated for all the plates, with and without the agents, to perform the adhesive tensile test by a dynamometer. The results show that the adhesive strength of the asphalt mat on the substrate equals 0.2 MPa, limit of the related standard, was met by all plates. All mixtures showed an increase in the adhesion of the cementitious material to the asphalt mat, when the additive concentration is increased. Only plates with Vinyl-0.50, SBR-0.50, Acrylic-0.25 and Acrylic-0.50 registered average strengths greater than 0.50 MPa, the minimum requirement of the related standard, and higher than the REF plate by 36%, 16%, 22% and 56%, respectively. The rest of the plates failed. Therefore, the influence on the performance in the adhesion of the composite to the asphalt mat is directly linked to the type of compatibilizing agent, as well as its concentration.

Influence of blending protocol on the mechanical, rheological, and electromagnetic properties of PC/ABS/ABS‐g‐MAH blend‐based MWCNT nanocomposites

AbstractPolycarbonate (PC)/acrylonitrile‐butadiene‐styrene copolymer (ABS) blend‐based multi‐wall carbon nanotubes (MWCNT) nanocomposites is an attractive alternative for the manufacture of electronics housing as it can have the mechanical and electromagnetic properties required for this application. The preferred location of MWCNT in PC/ABS blend is an important parameter to obtain better mechanical and electromagnetic properties. In this way, three different blending protocols (BP) were used to obtain PC/ABS/maleic anhydride‐grafted ABS (ABS‐g‐MAH) (85/10/5) blend‐based MWCNT nanocomposites with the addition of 0.5 and 1 wt% of MWCNT in a twin‐screw extruder. Specimens were evaluated by thermal (thermogravimetric analysis—TGA and differential scanning calorimetry—DSC), mechanical (Izod impact strength and tensile tests), dynamic mechanical analysis (DMA), electrical, and rheological properties, which were correlated with the nanocomposites morphology evaluated by high‐resolution scanning electron microscopy. The BP associated with the addition of a compatibilizer agent influenced the MWCNT distribution and location in the polymeric matrix. The one‐step extrusion process results in MWCNT mostly at the interface of the PC/ABS blend and agglomerates, leading to lower mechanical and thermal properties. The BP in which a PC/MWCNT masterbatch was first prepared and then diluted in ABS and ABS‐g‐MAH achieves the higher mechanical properties, increasing Young's modulus and the ultimate tensile strength. The third BP in which MWCNT was added in a second step in the blend already processed resulted in a homogeneous dispersion of MWCNT on both phases and a lower electrical resistivity.