Mechanical Properties Of Blends Research Articles

Production Processing for the Beneficiation of Waste Polythylene Product

The large amount of post-consumer polyethylene terephthalate (PET) bottles/containers and post-consumer sachet water nylon currently generated in Lagos State makes imperative the search for alternative procedures for treating, recycling or reuse of these waste materials. This is because they are not biodegradable and constitute environmental and health threat to the survival of man and other living things. The sustainable approach to municipal solid waste management in Nigeria is being considered. This research work aimed at recycling of post-consumer PET bottles/containers and post-consumer sachet water nylon to produce composite materials for engineering applications and wastes storage bag (wastes bin) respectively. Plastic waste, polyethylene terephthalate (PET) bottles/containers and sachet water nylon coming from the dumpsites in Lagos State in Nigeria were collected, separated, washed, recycled, extruded and characterized. The products obtained were subjected to tests to evaluate their mechanical properties using Introns Tester Model 1122. The results showed that the PET/LDPE blend mechanical properties depend on the processing conditions and apparatus. High processing temperature and high residence times strongly enhance the degradation processes and reduce the mechanical properties, in particular the elongation at break. However, by introducing additives, such as antioxidants, inert fillers and impact modifiers, these mechanical properties are improved and approached those products made from of virgin polyethylene terephthalate. For the recycled sachet water nylon, the results also showed that there was mechanical properties deficiency in the use of recycled resins and that this deficiency could be minimized through adequate blending with virgin resins. In general, provided that optimal reprocessing conditions with suitable additives, the mechanical properties of the recycled resins are near to those of virgin resins.

Thermal and mechanical properties of gamma-irradiated prevulcanized natural rubber latex/low nitrosamines latex blends

ABSTRACTThermal and mechanical properties of blended radiation prevulcanized natural rubber latex (RVNRL) and low nitrosamines latex (LNL) were studied. RVNRL was blended with LNL at various composition ratios. From the tensile test, it was found that the optimum tensile value was attained at a total blending ratio of 70% RVNRL and 30% LNL. Latex blending with optimum tensile strength was then subjected to gamma irradiation at various doses with the presence and absence of methyl methacrylate (MMA) at 10 pphr. It was found that the gamma irradiation of latex blend with the presence of MMA could help increase further the tensile value. Composition of blending at a specific ratio and gamma irradiation at a specific dose has led to a significant improvement in the mechanical properties of the latex blend. The formation of grafting in the latex blend was characterized by Fourier transform infrared spectra (FTIR) spectroscopy and differential scanning calorimetry (DSC). FTIR spectroscopy confirmed that MMA could be grafted onto blended latex effectively under appropriate irradiation conditions. Two new peaks at 1731 and 1149 cm−1 were observed after irradiation, indicating the presence of an ester group from poly(methyl methacrylate) (PMMA), which was grafted onto rubber chains. This finding was proved by the presence of new Tg in DSC analysis. The increase in new Tg indicates the movement of grafting chains, which are tightly bound onto rubber chains.

Preparation and properties of reactive polyurethane polyacrylate blends based on carbonyl‐hydrazide reaction

ABSTRACTA new reactive polyurethane/polyacrylate (PU/PA) blend was developed by mixing a core–shell polyacrylate latex containing keto groups in shell layer and a polyurethane dispersion incorporating multiple hydrazide groups which was synthesized by introducing the poly‐hydrazide groups into the end of the vinyl‐terminated polyurethane chains. Fourier transform infrared (FTIR) spectroscopy and gel permeation chromatography (GPC) results indicated that poly‐hydrazide groups had been incorporated in the polyurethane chains. Transmission electron microscopy (TEM) micrograph revealed that polyacrylate particles had a clear core–shell structure. The results of FTIR, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) indicated that the crosslinking reaction between two polymer systems had happened and crosslinking structure could effectively improve the compatibility between PA and PU. Thermogravimetric analysis (TGA) and mechanical tests results suggested that crosslinking structure could enhance the thermal stability and mechanical properties of blends. The influence of the PA content and the n(CO)/n(NHNH2) ratio on the hardness, water resistance, solvent resistance, and gel fraction of the blend films were comprehensively studied. The optimal PA content and n(CO)/n(NHNH2) ratio was 30% and 1.5:1 in this experiment, respectively. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44443.

Toughened Isotactic Polypropylene: Phase Behavior and Mechanical Properties of Blends with Strategically Designed Random Copolymer Modifiers

A series of poly(cyclohexylethylene-ran-ethylene) (CE) copolymers were synthesized with statistical segment lengths designed to match that of isotactic poly(propylene) (iPP). Melt blending the CE compounds containing 50–70 wt % cyclohexylethylene repeat units with iPP at loadings between 5 and 20 wt % resulted in a dispersion of CE droplets with number-average diameters between 150 and 500 nm as determined by scanning electron microscopy. Linear dynamic mechanical elastic (G′) and loss (G″) moduli data were fit to the Palierne model providing estimates for the interfacial tension between iPP and CE, which was interpreted based on enthalpic (χH) and entropic (χS) contributions to the overall segment–segment interaction parameter, χ = χH + χS, attributed to density and statistical segment length differences, respectively. The small particle sizes are explained by a reduced interfacial tension, driven by minimization of χS (≈0), counterbalanced by χH > 0, establishing an optimal balance between phase separat...

Effect of γ-Ray-Radiation-Modified Graphene Oxide on the Integrated Mechanical Properties of PET Blends

The surface modification of graphene oxide (GO) determines the interactions between GO and polymers, which possibly produces a significant impact on the mechanical properties of polymer. Here, GO was first modified with poly(glycidyl methacrylate) (PGMA) and triethylenetetramine (TTA) through γ-ray radiation. Then, a tiny small amount (0.04%) of the prepared modified GO was filled with a PET/ethylene-methyl acrylate-glycidyl methacrylate random terpolymer (PET/ST2000) blend. The morphological analyses on these filled PET blends confirmed that the surface chemical structure of GO had a crucial impact on the mechanical property of the blend. The chemical bonding between GO and ST2000 was more efficient in improving the dispersibility of GO and the compatibility between PET and ST2000, leading to a 2.5-fold increase in the impact strength, along with a slight increase in tensile strength. However, the addition of reduced GO lacking polar groups caused fatal damage in the mechanical property of the blend.

In situ composites based on blends of PEEK and thermotropic liquid crystalline polymer

ABSTRACTA series of blends were prepared by mixing pellets of the thermotropic liquid crystalline polymers (TLCP) with poly (ether ether ketone)(PEEK) in the dry state under injection mouldingmolding conditions. The mechanical properties of blends were measured, and it is proved that the mechanical properties of blends are better than those of their matrix. Compared with the thermoplastic matrix, the tensile modulus and strength of the blends increased obviously, with the addition of only 2 wt% LCP. At the same time, the addition of TLCP decreased the melt viscosity of the blends.

Improvement of the Toughness and Crack Propagation Resistance Properties of Poly(Phenylene Sulfide)

Poly(phenylene sulfide) (PPS) is a high-performance thermoplastic engineering polymer, which exhibits outstanding properties such as electrical insulation, dimensional and thermal stability, chemical resistance, etc. In addition to this, PPS has a high degree of crystallinity and it exhibits good physical properties at elevated temperatures. Owing to these properties, PPS is widely used in electrical and electronic components, automobile industry and mechanical applications. These outstanding properties of PPS can be attributed to its chemical structure, composed of phenyl groups linked by a sulfur atom, which gives rigidity to the chain. On the other hand, the brittleness with low elongation strain, toughness and crack propagation resistance also restricts its further applications. Several methods are used to overcome these undesirable properties of PPS. Blending of PPS with other polymers is one of these methods. In this study, Ethylene-Acrylic Ester-Glycidyl Methacrylate terpolymer (Lotader®-AX8900) was used to improve the toughness and crack propagation resistance properties of PPS. For this purpose, PPS/Lotader (0, 2, 5, 10 wt.% Lotader) blends were prepared at various compositions. The blends were manufactured using laboratory scale twin screw extruder and injection molding machine. Mechanical properties of blends were investigated by using tensile test method. In addition to this, crack propagation and toughness of samples were investigated by using essential work of fracture (EWF) method. As a result of this study, it was found that Lotader addition significantly increases the toughness and crack propagation resistance of PPS.

Effect of heterogeneous nucleation on isotactic polypropylene-polyoxymethylene blends properties and miscibility

This paper presents a study of the effect of heterogeneous nucleation on isotactic polypropylene-polyoxymethylene (iPP-POM) blends properties and miscibility. Polyoxymethylene have been blended with polypropylene matrix in three different amounts: 25, 50, and 75 wt% with and without sorbitol based nucleating agent. Thermal and mechanical properties of blends have been investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dynamic mechanic thermal analysis (DMTA), static tensile test as well as rheological analysis. The structure of the blends was investigated using Scanning Electron Microscopy (SEM) and polarized optical microscopy (PM). Rheological analysis confirmed that the iPP-POM blends are partially miscible in a molten state. Open image in new window

Non-Covalent Polymeric Wrapping of IGEPAL C0890 for Graphene Nanoplatelets (GNPs-C0890) Filled NR/EPDM Rubber Blend Nanocomposites

Graphene nanoplatelets (GNPs) surface modification was performed by using a simplified dual-action of ultrasonication and high speed mechanical shearing. This approach induced a non-covalent polymeric wrapping interaction between GNPs surfaces with IGEPAL-C0890 (ethoxylated nonyl phenol with 40 moles ethylene oxide). Various characterization tools like FTIR, Raman spectroscopy, FESEM and TEM were utilized to confirm the success of the surface treatment. The efficacy and suitability of non-covalent treated GNPs-C0890 as nanofiller reinforcement and inorganic compatibilizer in NR/EPDM rubber blends were evaluated. Effects of GNPs-C0890 loading variation to the mechanical tensile properties and fracture morphologies of NR/EPDM nanocomposites rubber blend were studied. It is interesting to note that the GNPs-C0890 was not able to reinforce NR/EPDM blend at a higher loading addition (≥ 3.00 wt.%) due to the agglomeration and crosslinking retardation phenomena by phase separation. However, at a lower loading (≤ 1.00 wt.%), the blend strengthening effects promise the improvement at about 64.55% of tensile strength and 14.20% of elongation percentage as compared than unfilled NR/EPDM blend. Obvious fractured morphological changes due to the absence and presence of GNPs provide hints on the role of GNPs treatment in effecting the NR/EPDM rubber blend mechanical properties.

Polylactide/Poly(ω-hydroxytetradecanoic acid) Reactive Blending: A Green Renewable Approach to Improving Polylactide Properties.

A green manufacturing technique, reactive extrusion (REx), was employed to improve the mechanical properties of polylactide (PLA). To achieve this goal, a fully biosourced PLA based polymer blend was conceived by incorporating small quantities of poly(ω-hydroxytetradecanoic acid) (PC14). PLA/PC14 blends were compatibilized by transesterification reactions promoted by 200 ppm titanium tetrabutoxide (Ti(OBu)4) during REx. REx for 15 min at 150 rpm and 200 °C resulted in enhanced blend mechanical properties while minimizing losses in PLA molecular weight. SEM analysis of the resulting compatibilized phase-separated blends showed good adhesion between dispersed PC14 phases within the continuous PLA phase. Direct evidence for in situ synthesis of PLA-b-PC14 copolymers was obtained by HMBC and HSQC NMR experiments. The size of the dispersed phase was tuned by the screw speed to "tailor" the blend morphology. In the presence of 200 ppm Ti(OBu)4, inclusion of only 5% PC14 increased the elongation at break of PLA from 3 to 140% with only a slight decrease in the tensile modulus (3200 to 2900 MPa). Furthermore, PLA's impact strength was increased by 2.4× that of neat PLA for 20% PC14 blends prepared by REx. Blends of PLA and PC14 are expected to expand the potential uses of PLA-based materials.

Effect of processing parameters on phase morphology and mechanical properties of thermoplastic polyurethane and polydimethylsiloxane rubber blends

Properties of polymer blends are generally controlled by the characteristics of the individual components, the processing conditions, morphology developed during processing and the interaction between the different blend constituents. The effect of processing parameters on the morphology of thermoplastic polyurethane (TPU)-polydimethylsiloxane rubber (PDMS) blends has been investigated in a Brabender Plastograph, an internal mixer. Phase morphology of the blends has been analyzed using image processing technique to assess the dispersed domain size, domain size distribution and area of each dispersed domain. Taguchi methodology has been adopted to quantify the effect of processing conditions on the mechanical properties of the TPU-PDMS blends. The average shear rate experienced inside the mixing chamber of Brabender Plastograph has been determined and this data has been correlated with the rheological properties to evaluate the viscosity ratio of the blends. The effect of viscosity ratio on the phase morphology of TPU-PDMS blends has been studied and the results are found to be in agreement with those of the effect of processing conditions on the mechanical properties of the blends. The lowest viscosity ratio leads to favorable droplet/matrix morphology resulting in higher mechanical strength properties. Palierne model has been used to estimate the interfacial adhesion between the polymer components in the blends of droplet/matrix morphology which is found to be as low as 3mN/m. This may considered to be the reason for a wide deviation from the log additive rule for the complex modulus of the blends.

Preparation of PMMA/PP/ PP-g-MAH Alloy

Studies of the polypropylene grafted with malefic anhydride PP-g-MAH as compatibilizer to toughening polypropylene PP and PMMA blends. When PP/PMMA fixed ratio of 80/20, the effects of PP-g-MAH content on the blend morphology, mechanical properties and thermal properties. With the increase of PP-g-MAH content, strength and impact strength, tensile strength, PMMA/PP/PP-g-MAH blends were first increased and then decreased, and in the PP-g-MAH for 5 copies and reached the maximum value; while the flexural strength increased. The impact strength of the alloy compared with the alloy without the addition of compatibilizer increased about 30%, the tensile strength, bending strength increase obviously. That PP-g-MAH has effects on the morphology and properties of PMMA/PP/ PP-g-MAH blend system.

Study of Waste Rubber Powder Blend Mechanical Properties of NR

The study of the mixing method, mixing time, waste rubber powder as the amount of waste rubber powder by resorcinol (R) and six methyl four amine (H) effect on the mechanical properties of waste rubber powder /NR blend modified. The results show that, with effect of blending method, mixing time and waste rubber powder content on mechanical properties of blend vulcanizate; through modification, can greatly improve the mechanical properties of waste rubber powder blend vulcanizates, as the modifier of resorcinol and six methyl four amine mass ratio was 1/0.5, glue the material mechanical properties are the best, the tensile strength is 17.03 MPa.

Miscibility, Thermal and Mechanical Properties of Poly(para-dioxanone)/Poly(lactic-co-glycolic acid) Blends

A series of biodegradable polymers was prepared by solution co-precipitation of poly(para-dioxanone) (PPDO) and poly(lactic-co-glycolic acid) (PLGA) in various blend ratios. Samples were compression-molded into bars using a platen vulcanizing press. The miscibility, thermal and mechanical properties of the materials were investigated using differential scanning calorimetry (DSC), polarized optical microscopy, and scanning electron microscopy (SEM). Dynamic contact angle was used to characterize the water wettability of PLGA/PPDO blends. The mechanical properties of blends and pure polymers were measured by tensile tests. The position of the glass transition temperatures (Tg) was dependent upon composition. When 10 % PLGA was added into PPDO, the DSC curve revealed only one Tg (−7.35 °C) which was located between the Tg values of PPDO and PLGA. When 20 % PLGA was added into the blend, two independent Tg values for PPDO/PLGA blends were observed, and such characteristics improved further upon addition of 30 % PLGA. SEM images of fractured surfaces displayed evidence of the morphology of PPDO/PLGA blends that were consistent with the DSC results. Hence, a relationship was found between homogeneity and the contents of PLGA in the blend. The compatibility of the blends increased with addition of small amounts of PLGA, followed by a leveling-off at higher content.

The Effect of Addition EVA and LDPE-g-MAH on Irradiated LDPE Filled with Metal Hydroxides

Electron beam irradiation efffects on polymer cross-linking used for wire and cable insulations are still being researched. This study showed that upon irradiation, ethylene vinyl acetate (EVA) and maleic anhydride grafted polyethylene (LDPE-g-MAH) addition as coupling agent to the LDPE/fillers, improved processing and mechanical properties of compounds at each irradiation dosage (0–110 kGy). A gradual increase in gel content (GC) and tensile strength (TS) with a concomitant decline in elongation at break (EB), hot set (HS) and densities of compounds were observed upon irradiation of the blends. Melt flow index test (MFI) results revealed that filler addition reduced compounds flowing and in consequence, caused difficult to process. The LDPE/EVA blends TS values decreased significantly with fillers addition (ATH, MH and ZB). Consequently, this study demonstrated that filler addition to irradiated low density polyethylene (LDPE) impaired processing and mechanical properties of compounds, whereas, LDPE-g-MAH (6–12 phr) and EVA (0–100 phr) addition to the compounds (1I–8I) improved the blends flowability and mechanical properties at each irradiation dose (0–110 kGy). Moreover, among additive fillers, MH content compounds presented the strongest adhesion forces with polymeric compounds compared with analog compounds content aluminum trihydrate (ATH) or zinc borate (ZB) at each irradiation dosage.

Degradation behaviors, thermostability and mechanical properties of poly (ethylene terephthalate)/polylactic acid blends

It is difficult for polyethylene terephthalate (PET) to degrade, which caused severe pollution. In this work, polylactic acid (PLA) was introduced to improve the degradation of PET. PET/PLA was synthesized by extrusion blending. The thermal, crystalline and mechanical properties of blends were investigated with TGA, DSC, WAXD and universal testing machine. The degradation of the blends in soil, acid and alkaline buffer solutions was assessed, respectively. It was found that the introduction of a little PLA promoted crystallization of PET during injection molding process. The starting decomposition temperature lowered from 412.1 °C of pure PET to 330.4 °C at 50% PLA content, tensile and bending strength of blends gradually decreased with the PLA content increasing, while the degradation rate improved. Alkaline environment was most beneficial for blends to degrade. The degradation mechanism was discussed.

Compatibilization of PMMA/PC Blends with Different Strategies: Transesterification Catalyst versus Nanoparticles

The efficiency of tin(II) 2-ethylhexanoate catalyst and hydrophilic silica nanoparticles in compatibilizing polycarbonate/poly(methyl methacrylate) (PMMA/PC) blends were compared in terms of the morphological, thermal, and mechanical properties. Both the catalyst and nanoparticles were found to refine the morphology of PMMA/PC blends. Although the blends with catalyst exhibited smaller phase size, they possessed more deteriorated mechanical performance and worse thermal properties than those of nanoparticle-filled ones due to the significant degradation during transesterification reactions. The addition of nanoparticles refined the morphology of PMMA/PC blends kinetically to a lesser extent. However, the thermal and mechanical properties of blends were improved noticeably upon the addition of nanoparticles. Finally, the mechanisms, advantages, and disadvantages of catalyst and nanoparticles in compatibilizing PMMA/PC blends were discussed and compared.

Cavitation in hard/soft/hard three-layer core-shell structural rubber particles

The microvoiding mechanisms and mechanical properties of blends of poly(viny1chloride)(PVC) with hard/soft/hard three-layer core-shell structural particles polystyrene/polybutadiene/polymethylmethacrylate (PSBM) are investigated. The core-shell particles ranging from 110 to 182 nm to 254 nm. Toughened blends with higher tensile strength are obtained, which is related to the presence of hard polystyrene glassy domains in the core acting as stiffening agents. Cavitation occurs in all size rubber, relieves the triaxial tension and thereby promotes shear yielding of the PVC matrix. The three layer structure of the particles provides multi- interface, which act as trigger of cavitation. Furthermore, cavitiation in the blend containing small particles (110 nm) is observed due to its higher tensile stress, under which the cavitation process can be completed.

Preparation of PAM/PVA blending films by solution-cast technique and its characterization: a spectroscopic study

Polyacrylamide (PAM) and poly(vinyl alcohol) (PVA) were blended with different weight percentages (70/30, 50/50, 30/70) using solution-cast technique. The prepared films were studied by different characterization techniques. The effect of PVA content on PAM blends was investigated by Fourier transform infrared (FTIR), ultra violet visible (UV–vis), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). Different mechanical properties of blends were also studied. Significant changes were observed in FTIR, UV–vis, TGA, SEM and mechanical analysis which revealed interactions between the two polymers. FTIR spectra showed the presence of hydrogen bonding between PAM and PVA and hydrophilic nature of the blends. Different optical properties were studied by UV–vis spectroscopy. The weight loss, as a function of temperature of blends, was analyzed by TGA. The results obtained from different experimental techniques were supported by SEM image analysis. FTIR analysis confirmed the conclusion on the specific hydrogen bonding between –CONH2 groups in PAM and –OH group in PVA. These results showed the change in the thermal stability and mechanical properties. FTIR analysis revealed that a blend ratio of 50/50 wt% had maximum intermolecular interaction between two polymers. It was finally concluded that blend films with the above ratio display higher thermal stability and improved mechanical properties. Due to changes in interactions, the optical parameters were also changed.

Effect of POSS on the Compatibility and Mechanical Properties of PC/PLA Blends

Polycarbonate/poly (lactic acid)/(PC/PLA) blends were modified by two kinds of POSS, glycidyl POSS (G-POSS) and Octa-ammonium POSS (O-POSS), respectively. The morphologies and mechanical properties of blends were investigated systematically. The results showed that the adding of O-POSS has a better effect on the compatibility of blend than adding G-POSS, the separate phase is invisible in the morphology of blends, and the mechanical properties of blends are improved significantly with the increase of added O-POSS.