Papers by Keyword: Polymer Blend

Abstract: In proton exchange membrane fuel cells, the substitution of hydrated Nafion^® for lower cost materials is compulsory. In this work, a material based on a two commercial polyarylenes blend, with chemical modification, has been developed. The dynamic properties of the material were evaluated, and correlated to microscopic morphology and physico-chemical properties. The material showed thermal resistance above 200 °C, and featured conductivities in the order of 10^-2 S cm^-1, measured at up to 90 °C. In order to obtain better microscopic phase separation, between the conducting polymer (sPEEK) and the structural polymer (PES), certain solvent mixtures were evaluated, based on polarity character. The NMP/DMSO (0,3/0,7 %(v/v)) solvent mixture formed the film with the best properties, under hydrated conditions. Microscopic phase separation was approached by theoretical calculation of solubility parameters as compared to experimental data. This is an unusual and promising approach, as well as modification of materials structure through solvent manipulation, which is a more practical and unexpensive procedure than synthesis of new polymer structures.

Abstract: Nowadays, environmentally conscious manufacturers make their products from partly or fully recycled materials. However, recycling of polymer blends can be difficult. In immiscible polymer blends, the components often contain reactive functional groups, therefore polymers with reactive functional groups can be used as reactive compatibilizers. I investigated the mechanical, thermal, and morphological properties of different recycled rPET/rHDPE blends. I used an anhydride modified polyethylene (HDPE-g-MAH) as a compatibilizer. I found that without compatibilizer, the elongation at break decreased with the increase of rHDPE. As the amount of compatibilizer increases, the elongation at break is gradually increased. Furthermore, based on the SEM images, it can be observed that the size of the dispersed rHDPE phase in the rPET matrix decreased with the addition of a compatibilizer, and the dispersion of the dispersed phase also improved.

Abstract: The dyeing ability of the polypropylene (PP) fiber was modified by blending with poly(lactic acid) (PLA). The PP, PLA, and PP/PLA fiber were obtained using the melt-spinning technique in the presence of the polypropylene-graft-maleic anhydride as a coupling. The dyeing ability, mechanical and thermal properties, and crystalline structure of the PP, PLA, and PP/PLA fibers were investigated. The effect of dyeing ability was measured using the CIE L^* a^* b^*. The a* value of the PP of 11.91 increased to 43.48 for PP/PLA90, showing a light pink to red color. The SEM images demonstrated smooth fiber with color coating on the fiber. The mechanical property of the fiber indicates that increasing the PLA decreased the tenacity of the PP fiber. The melting behavior of fiber increased with the PLA. The XRD presented the PP's crystalline and the PLA's amorphous structures.

Abstract: The utilization of recycled materials in the production of plastic products is an environmentally conscious and economically viable approach. This study delves into the mechanical and flow properties of low-density polyethylene (LDPE) blends, comparing virgin low-density polyethylene (vLDPE), recycled low-density polyethylene (rLDPE) and vLDPE/rLDPE blends with different ratio (100/0, 75/25, 50/50, 25/75, 0/100) for the purpose of reprocess into variable high-quality end products with minimal modification. Mechanical properties, such as tensile strength, elongation at break, Young’s modulus, flexural strength, and flexural modulus, were examined to assess the suitability of rLDPE in comparison to its virgin counterpart. Our results demonstrate that vLDPE/rLDPE blend exhibits mechanical properties comparable to those of vLDPE, suggesting its potential as a sustainable alternative for reprocessing. Flow properties, specifically melt flow index (MFI), were also assessed to evaluate the processability of the LDPE blends. The findings reveal that the flow properties of LDPE blends are within an acceptable range for extrusion moulding, indicating that these materials can be effectively processed without major adjustments to manufacturing processes. This research underscores the feasibility of incorporating rLDPE into vLDPE for reprocessing into variable products, offering both economic and environmental advantages. By extending the lifecycle of LDPE materials through recycling, we can contribute to reducing waste and the overall environmental footprint while maintaining the desired mechanical and flow properties for high-quality end products.

Abstract: The compatibility of polymers based on the blending of methyl methacrylate (PMMA) and depolymerized polyethylene terephthalate (DPET) was studied in this investigation. Initially, the PET was obtained using the waste bottle before the depolymerization process to get the final product of DPET. Here, the preparation of the polymer blend used was carried out by mixing the two polymers manually. The affinity of the polymers to each other is conducted using Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). The results of FT-IR indicate that some bands were shifted, some of them were decreased, and the others were eliminated by the addition of DPET to PMMA. This behavior can be attributed to interaction and coordination between the PMMA and DPET. Based on DSC analysis, the melting temperatures of PMMA and DPET blends were reduced as compared to pure PMMA, with the exception of the 99/1 (PMMA/DPET) blend. PMMA's surface morphology reveals a rough surface with a micropore structure. The appearance of pure DPET in the SEM image shows a rough surface with diverse shaped and sized particles. Also, the 5/95 (DPET/PMMA) blend doesn't seem to have any visible phase separation. Keywords: Compatibility, polymer blend, PMMA, DPET

Abstract: Nowadays, we can choose a carrier bag made of traditional LDPE or a biodegradable polymer to pack vegetables, bakery products, and other products in more and more shops. However, the customers and the selective waste collection system are not yet prepared for the separate collection of compostable biopolymers. Therefore, they are mixed in the plastic waste stream. Therefore, the aim of the study was to analyze the mechanical and optical properties, and the compostability of different low-density polyethylene (LDPE) and poly (butylene adipate-co-terephthalate) (PBAT) compounds. We made different compounds from LDPE and PBAT by twin-screw extrusion and blown films from the regranulates. We investigated the tensile and optical properties and the biodegradability of the blown films. The tensile test showed that the "contaminants" had a more significant effect on elongation at break than tensile strength. We observed that the haze of the LDPE-based blends increased with an increasing weight fraction of PBAT. We found that PBAT-based samples were completely disintegrated in 42 days, regardless of the weight fraction of LDPE.

Abstract: This study investigated the effect of polylactic acid (PLA) on the mechanical properties and biodegradability of a ternary blend comprising of thermoplastic starch (TPS), Polybutylene adipate terephthalate (PBAT) and PLA. The binary blend (TPS/PBAT) and ternary blend (TPS/PBAT/PLA) with various contents of PLA were prepared through a twin-screw compounding using an intensive mixing screw design. In order to observe the microstructure in blends, the SEM observation revealed the two types of morphology in the blends including (1) some TPS domain that still remained immiscible in all blends and (2) the partially compatible of binary and ternary blends. For the mechanical properties of the blends, the addition of the PLA component led to an improvement of the tensile strength and modulus. For the simple soil burial test, it found that binary film was fully disintegrated within one month, whereas the ternary blend films were also broken down but still remained in small pieces of fragile films. Finally, it can be suggested that the presence of TPS brought to the biodegradation of blends in soil burial test, while incorporating with PLA led to retardation in degradation rate.

Abstract: Fourier Transform Infrared (FT-IR), was applied to investigate the complexation, structural, ionic transport properties and dominant charge carrier species in Chitosan (CS) / Methyl Cellulose (MC) blend doped with 1 – butyl – 3 – methylimidazolium bis (trifluorosulfonyl) imide (BMIMTFSI) solid biopolymer electrolytes (SBEs) which have been prepared via solution casting technique. Samples were partially opaque in appearance with no phase separation. The occurrence of interactions between the host polymer CS/MC blend and ionic dopant BMIMTFSI were proven by FT-IR analysis from the shift in C-O band in 1049 cm^-1. The FTIR spectrum in the region between 1080 and 980 cm⁻¹ were deconvoluted using Origin 8 software to disclose the percentage of free mobile ions and contact ion of the samples. Ionic transport properties analysis reveals that the ionic conductivity is dependent on the ionic mobility (μ) and diffusion of ions (D).Keywords: Biopolymer Electrolyte; Polymer Blend; Chitosan, Methylcellulose; BMITFSI; Ion transport.

Abstract: First investigations focus on the usage, processing and material properties of polycarbonate (PC) based materials used in cable duct production. Test coupons were taken from in-situ cable ducts including further additives generally used in industry. Different mechanical and optical analytical methods were performed. Significant differences in tensile properties of polycarbonate/ acrylonitrile butadiene styrene (PC/ABS) compared to mineral reinforced PC were observed. The hardness of mineral reinforced PC is significantly dependent on the geometry of the cable ducts. The fracture behavior and morphology of the PC/ABS fracture surface is directly related to the coupon temperature during Charpy impact testing. The process temperature influences the failure behavior during high impact processing such as high speed punching. Due to the lower impact strength of mineral reinforced PC less film and burr formation compared to PC/ABS are likely. However, the mineral distribution is not homogeneous and therefore subject to further investigation. This study aims at a better understanding of process properties of PC/ABS products, parameter selection, quality improvement and general understanding of underlying microstructural and surface properties.

Abstract: Blended polymer composites are prepared based on linear low density polyethylene (LLDPE) and mixed with polysulfone (PSU) using solvent casting technique. LLDPE is functionalized with carbonyl functional groups to enable it to interact with PSU from the molecular level. Various weight percent of PSU is added into LLDPE to find the optimum weight percent ratio between LLDPE and PSU. The highest glass transition temperature obtained is 47.58°C for ratio LLDPE to PSU of 7:3. In addition, value for decomposition temperature is increased up to 490.16°C with the increasing of PSU content. SEM observation of the blended polymer films shows that glass transition and decomposition temperature depend on morphology of the blended polymers.