Different Combinations Of Polymers Research Articles

Recycling of Plastics in the Automotive Sector and Methods of Removing Paint for Its Revalorization: A Critical Review.

The presence of plastics in the automotive industry is increasingly significant due to their lightweight nature, which contributes to reducing fuel consumption and CO2 emissions while improving versatility and mechanical properties. Polypropylene (PP) and other polyolefins are among the most commonly used materials, especially for components such as bumpers. The use of composite materials, i.e., a combination of different polymers, improves the properties through synergistic effects, thereby also improving the performance of the final product. In the automotive industry, PP reinforced with 20% talc or CaCO3 is commonly used. The mechanical recycling of polypropylene bumpers is the most common type of recycling. However, challenges arise during this process, such as the presence of impurities like paint, chemical contaminants from previous use, and polymeric impurities from different polymers mixed into the polymer matrix, among others. Paint affects both the aesthetic quality and the mechanical and intrinsic properties of the recycled material. This review aims to analyze the main methods reported in the literature, focusing on those with low environmental impact. Furthermore, these methods are classified according to their capacity, effectiveness, substrate damage, environmental hazards, and economic feasibility. It also aims to offer a comprehensive overview of the mechanical recycling of plastic waste in the automotive industry.

Formulation Development and Evaluation of Transdermal Patches of Apigenin.

Apigenin is a flavonoid that is abundantly present in fruits and vegetables. It has a diverse range of therapeutic properties, including cardioprotective, neuroprotective, analgesic, and cancer-preventive effects. Its safety profile, even at higher doses, makes the compound particularly valuable. Apigenin, along with excipients, was used to formulate patches using the solventcasting method on a glass mold. Seven distinct batches of patches were formulated using different combinations of polymers. The drug-polymer ratios employed in these formulations were (1:2), (1:3), (1:4), (1:4), (1:(2:8), (1:(1:9), and (1:(2:8) for both drugs. The formulated patches were evaluated and results indicate that the transdermal patches (TP5) have promising results.

Solubility and Dissolution Enhancement of Rosuvastatin Calcium by Using HPMC & Guar Gum Polymers and Formulated into Capsule Dosage Form

The main objective of the current study was to prepare the solid dispersions of Rosuvastatin calcium and formulated into capsule dosage form with the combination of different polymers. Solid dispersions are prepared by fusion method by using combination of polymers in different concentrations such as HPMC and Guar gum. Solid dispersion technique will be selected as an efficient means for improving the solubility, dissolution rate and improves the bioavailability of water insoluble drugs. Solid dispersion of Rosuvastatin by the above mentioned method increases the dissolution rate of Rosuvastatin. These solid dispersions will be evaluated by parameters such as drug content, solubility, X-RD, percentage yield, DSC and in-vitro dissolution profile. The stability study of the formulations as per ICH guideline Q1A in stability chamber both at intermediate and accelerated conditions ascertained that the formulations are stable at wide range of storage conditions.

Development and Comparative Analysis of Metronidazole Microspheres Prepared with Different Combinations of Polymers Using Ionotropic Gelation Technique

Development and Comparative Analysis of Metronidazole Microspheres Prepared with Different Combinations of Polymers Using Ionotropic Gelation Technique

INVESTIGATION OF SOLID DISPERSION APPROACH FOR THE IMPROVEMENT OF PHARMACEUTICAL CHARACTERISTICS OF TELMISARTAN USING A CENTRAL COMPOSITE DESIGN

Objective: The goal of this study was to use a solid dispersion approach to improve the aqueous solubility and dissolution rate of Telmisartan. Methods: Design of experiment trials was conducted following a central composite design with different combinations of polymers and stirrer rpm and the selected responses (drug release, entrapment efficiency) were determined. The selected optimized formulation was characterized by Fourier-transform infrared spectroscopy, differential scanning calorimetry, scanning electron microscopy, and X-ray diffraction, which reflected the changes that occurred in API and excipients after conversion in to the formulation. Results: In the design of experiments, central composite design was implemented and it was observed that polymers concentration (polyvinyl pyrrolidine K25, polyethylene glycol 4000) and stirrer rpm were having a significant impact on the responses (drug release, entrapment efficiency), and variables were having p-value<0.05 which reflected the significant impact. The results of stability study showed a significant no decrease in drug assay values, which reflected the stability behavior of the formulation. The results of comparative dissolution studies revealed that the optimized formulation have improved the drug solubility and dissolution rate. Conclusion: It can be concluded that optimized telmisartan-loaded solid dispersion improved the solubility and dissolution rate of Telmisartan. The optimized formulation was having release>85% release within 30 min. Further, the stability of the formulation was also assessed under the accelerated condition as per ICH which reflected their stability. So, this approach can be employed for improving dissolution rate of other BCS II class drugs.

Spray-dried microparticles of encapsulated gefitinib for slow-release localized treatment of periodontal disease

Periodontal disease (PD) can be prevented by local or systemic application of epidermal growth factor receptor inhibitors (EGFRIs) that stabilize αvβ6 integrin levels in the periodontal tissue, leading to an increase in the expression of anti-inflammatory cytokines, such as transforming growth factor-β1. Systemic EGFRIs have side effects and, therefore, local treatment of PD applied into the periodontal pockets would be preferrable. Thus, we have developed slow-release three-layered microparticles of gefitinib, a commercially available EGFRI. A combination of different polymers [cellulose acetate butyrate (CAB), Poly (D, L-lactide-co-glycolide) (PLGA) and ethyl cellulose (EC)] and sugars [D-mannose, D-mannitol and D-(+)-trehalose dihydrate] were used for the encapsulation. The optimal formulation was composed of CAB, EC, PLGA, mannose and gefitinib (0.59, 0.24, 0.09, 1, and 0.005 mg/ml, respectively; labeled CEP-gef), and created microparticles of 5.7 ± 2.3 µm in diameter, encapsulation efficiency of 99.98%, and a release rate of more than 300 h. A suspension of this microparticle formulation blocked EGFR phosphorylation and restored αvβ6 integrin levels in oral epithelial cells, while the respective control microparticles showed no effect.

Studying the concentration of polymers in blended microplastics using 2D and 3D Raman mapping

The combination of different polymers in the form of blended plastics has been used in the plastic industry for a long time. Nevertheless, analyses of microplastics (MPs) have been mainly limited to the study of particles made of single-type polymers. Accordingly, two members of the Polyolefins (POs) family, i.e., Polypropylene (PP) and Low-density Polyethylene (LDPE) are blended and extensively studied in this work due to their applications in industry as well as abundance in the environment. It is shown that 2-D Raman mapping only provides information about the surface of blended MPs (B-MPs). While complimentary 3-D volume analysis is needed to fully understand the presence of various polymers in such complex samples. Therefore, 3-D Raman mapping is applied to visualize the morphology of the distribution of polymers within the B-MPs together with the quantitative estimation of their concentrations. A parameter defined as the concentration estimate error (CEE) evaluates the precision of the quantitative analysis. Furthermore, the impact of four excitation wavelengths 405, 532, 633, and 785 nm is investigated on the obtained results. Finally, the application of a line-shaped laser beam profile (line-focus) is introduced for reducing the measurement time from 56 to 2 h.

Sustained Release Floating Matrix Tablets of Ciprofloxacin Using Combination of Different Polymers

Drug delivery to the exact site of action become the key to the overall effectiveness of the drug, but when it comes to gastric ulcers it is a rate determining parameter and most crucial factor to play in the treatment of ulcers.More often, drug absorption is unsatisfactory and highly variable among and between individuals, despite excellent in vitro release patterns. The reasons for this are essentially physiological and usually affected by the GI transit of the form, especially its gastric residence time (GRT), which appears to be one of the causes of the overall transit time variability. Over the past three decades, the pursuit and exploration of devices designed to be retained in the upper part of the gastrointestinal (GI) tract has advanced consistently in terms of technology and diversity, encompassing a variety of systems and devices such as floating systems, raft systems, expanding systems, swelling systems, bioadhesive systems and low-density systems. Gastric retention will provide advantages such as the delivery of drugs with narrow absorption windows in the small intestinal region. Also, longer residence time in the stomach could be advantageous for local action in the upper part of the small intestine, for example treatment of peptic ulcer disease .The present research work aims to formulate and evaluate sustained release floating matrix tablets of Ciprofloxacin using combination of different polymers.

Investigation of the fabrication of nanofibers from aqueous polyvinyl alcohol solutions by electrospinning

Polyvinyl alcohol (PVA) refers to polymers that have great potential for medical and technical applications. Especially, the possibility of its medical application in nanofibres is of great interest due to its good water solubility, high biocompatibility and non-toxicity. PVA is used for various pharmaceutical and biomedical purposes, as a carrier for the delivery of proteins and drugs, as dressings, filter materials, and as artificial organs. Currently, many drug delivery systems have been developed, such as hydrogels or complex electronic microchips. Nanostructural materials are particularly advantageous for rapid drug release due to their high surface area to volume ratio. Both natural and synthetic polymers can be used to produce nanofiber materials, but the combination of different polymers (synthetic and natural) and the incorporation of various biologically active substances into them provides special properties to the finished materials. In this work, the properties of aqueous solutions based on polyvinyl alcohol were investigated: electrical conductivity, viscosity and pH. The influence of technological parameters of electroforming process on obtaining nanofibers from aqueous solutions of PVA. The optimum PVA concentration for the formation of nanostructures was determined equal to 8 wt.%. At this concentration, the PVA solution has electrical conductivity, viscosity and pH equal to 571 µS/cm, 107.23 mPa·s and 6.14 respectively. As part of the study, the electroforming process parameters were obtained to enable the production of nanofibers with a diameter of about 170 nm: distance between needle and collector 140 mm, spinning solution feed rate 0.2 ml/h and voltage between needle and collector 30 kV.

Textiles for Circular Fashion: The Logic behind Recycling Options

For the textile industry to become sustainable, knowledge of the origin and production of resources is an important theme. It is expected that recycled feedstock will form a significant part of future resources to be used. Textile recycling (especially post-consumer waste) is still in its infancy and will be a major challenge in the coming years. Three fundamental problems hamper a better understanding of the developments on textile recycling: the current classification of textile fibres (natural or manufactured) does not support textile recycling, there is no standard definition of textile recycling technologies, and there is a lack of clear communication about the technological progress (by industry and brands) and benefits of textile recycling from a consumer perspective. This may hamper the much-needed further development of textile recycling. This paper presents a new fibre classification based on chemical groups and bonds that form the backbone of the polymers of which the fibres are made and that impart characteristic properties to the fibres. In addition, a new classification of textile recycling was designed based on the polymer structure of the fibres. These methods make it possible to unravel the logic and preferred recycling routes for different fibres, thereby facilitating communication on recycling. We concluded that there are good recycling options for mono-material streams within the cellulose, polyamide and polyester groups. For blended textiles, the perspective is promising for fibre blends within a single polymer group, while combinations of different polymers may pose problems in recycling.

Formulation and characterisation of alginate hydrocolloid film dressing loaded with gallic acid for potential chronic wound healing

Background: A dramatic growth in the prevalence of chronic wounds due to diabetes has represented serious global health care and economic issues. Hence, there is an imperative need to develop an effective and affordable wound dressing for chronic wounds. Recent research has featured the potential of bioactive compound gallic acid (GA) in the context of wound recovery due to their safety and comparatively low cost. However, there is a scarcity of research that focuses on formulating GA into a stable and functional hydrocolloid film dressing. Thus, this present study aimed to formulate and characterise GA-loaded alginate-based hydrocolloid film dressing which is potentially used as low to medium suppurating chronic wound treatment. Methods: The hydrocolloid composite films were pre-formulated by blending sodium alginate (SA) with different combinations of polymers. The hydrocolloid films were developed using solvent-casting method and the most satisfactory film formulation was further incorporated with various GA concentrations (0.1%, 0.5% and 1%). The drug-loaded films were then characterised for their physicochemical properties to assess their potential use as drug delivery systems for chronic wound treatment. Results: In the pre-formulation studies, sodium alginate-pectin (SA-PC) based hydrocolloid film was found to be the most satisfactory, for being homogenous and retaining smoothness on surface along with satisfactory film flexibility. The SA-PC film was chosen for further loading with GA in 0.1%, 0.5% and 1%. The characterisation studies revealed that all GA-loaded films possess superior wound dressing properties of acidic pH range (3.97-4.04), moderate viscosity (1600 mPa-s-3198 mPa-s), optimal moisture vapor transmission rate (1195 g/m 2/day, 1237g/m 2/day and 1112 g/m 2/day), slower moisture absorption and film expansion rate and no chemical interaction between the GA and polymers under FTIR analysis. Conclusion: An SA-PC hydrocolloid film incorporated with gallic acid as a potentially applicable wound dressing for low to medium suppurating chronic wounds was successfully developed.

Preparation and In Vitro Evaluation of Aspartic/Alginic Acid Based Semi-Interpenetrating Network Hydrogels for Controlled Release of Ibuprofen.

Different combinations of polymers, aspartic acid (ASP), alginic acid (AL), and monomer acrylic acid (AA) were crosslinked in the presence of an initiator ammonium peroxodisulfate (APS) and cross-linker ethylene glycol dimethacrylate (EGDMA) to develop aspartic acid/alginic acid-co-poly(acrylic acid) (ASP/ALPAA) (semi-interpenetrating polymer network (SIPN)) hydrogels by the free radical polymerization technique for the controlled delivery of ibuprofen (IBP). Various studies such as dynamic swelling studies, drug loading, in vitro drug release and sol−gel analysis were carried out for the hydrogels. Higher swelling was observed at higher pH 7.4 as compared to lower pH 1.2, due to the presence of carboxylic groups of polymers and the monomer. Hence, pH-dependent swelling was exhibited by the developed hydrogels which led to a pH-dependent drug release and vice versa. The structural properties of the hydrogels were assessed by FTIR, PXRD, TGA, DSC, and SEM which confirmed the fabrication and stability of the developed structure. FTIR analysis revealed the reaction of both polymers with the monomer during the polymerization process and confirmed the overlapping of the monomer on the backbone of the both polymers. The disappearance of high intense crystalline peaks and the encapsulation of the drug by the hydrogel network was confirmed by PXRD. TGA and DSC showed that the developed hydrogels were thermally more stable than their basic ingredients. Similarly, the surface morphology of the hydrogels was analyzed by SEM and showed a smooth surface with few pores. Conclusively, ASP/ALPAA hydrogels have the potential to deliver IBP for a long period of time in a controlled way.

Novel water‐soluble polymer coatings controlNPKrelease rate, improve soil quality and maize productivity

AbstractWe investigated different combinations of polymers (5% each) (i) starch, gelatin (polymer coating; PC‐1), (ii) polyvinyl alcohol (PVA), gum Arabica (PC‐2), (iii) PVA, gelatin (PC‐3), (iv) starch, gum Arabica (PC‐4), (v) gelatin, gum Arabica (PC‐5), (vi) starch, PVA (PC‐6), for coating NPK (17, 17:17) in a fluidized bed granulator. Morphological characterization indicated a uniform coating of all formulations on NPK granules. A slow release of N (PC‐3), P (PC‐6), and K (PC‐3) was observed in water. In soil, high mineral N (63%), plant‐available P (72%), and K (24%) were observed in PC‐3, PC‐5, and PC‐6, respectively than uncoated fertilizer. Microbial biomass NPK was also higher in these treatment. This resulted in higher maize yield (66%), N (114%), P (164%), and K (137%) uptakes and apparent N (267%), P (196%), and K (358%) recoveries from applied fertilizer in these treatments. Among these, PC‐3 resulted in an increase of 115% shoot N, 169% P and 138% K uptakes and 268% apparent N, 206% P and 361% K recoveries than uncoated fertilizer. Hence, coating of NPK with this biodegradable polymer combination controlled N, P, and K release and synchronized these nutrients availabilities with maize nutrients demand therefore resulted in higher maize crop yield and nutrient utilization efficiencies.

Formulation and characterisation of alginate hydrocolloid film dressing loaded with gallic acid for potential chronic wound healing.

Background: A dramatic growth in the prevalence of chronic wounds due to diabetes has represented serious global health care and economic issues. Hence, there is an imperative need to develop an effective and affordable wound dressing for chronic wounds. Recent research has featured the potential of bioactive compound gallic acid (GA) in the context of wound recovery due to their safety and comparatively low cost. However, there is a scarcity of research that focuses on formulating GA into a stable and functional hydrocolloid film dressing. Thus, this present study aimed to formulate and characterise GA-loaded alginate-based hydrocolloid film dressing which is potentially used as low to medium suppurating chronic wound treatment. Methods: The hydrocolloid composite films were pre-formulated by blending sodium alginate (SA) with different combinations of polymers. The hydrocolloid films were developed using solvent-casting method and the most satisfactory film formulation was further incorporated with various GA concentrations (0.1%, 0.5% and 1%). The drug-loaded films were then characterised for their physicochemical properties to assess their potential use as drug delivery systems for chronic wound treatment. Results: In the pre-formulation studies, sodium alginate-pectin (SA-PC) based hydrocolloid film was found to be the most satisfactory, for being homogenous and retaining smoothness on surface along with satisfactory film flexibility. The SA-PC film was chosen for further loading with GA in 0.1%, 0.5% and 1%. The characterisation studies revealed that all GA-loaded films possess superior wound dressing properties of acidic pH range (3.97-4.04), moderate viscosity (1600 mPa-s-3198 mPa-s), optimal moisture vapor transmission rate (1195 g/m 2/day, 1237g/m 2/day and 1112 g/m 2/day), slower moisture absorption and film expansion rate and no chemical interaction between the GA and polymers under FTIR analysis. Conclusion: An SA-PC hydrocolloid film incorporated with gallic acid as a potentially applicable wound dressing for low to medium suppurating chronic wounds was successfully developed.

Gelation kinetics of PAM/PEI based drilling mud for lost circulation applications

The problem of lost circulation is a direct consequence of the presence of fractures or high permeability. Lost circulation material (LCM) is used to treat the loss that occurs or proactively strengthen the wellbore of the potential loss zones. The polyacrylamide (PAM)/Polyethylenimine (PEI) cross-linkable polymer gel is proven to work best in zone-sealing and plugging applications. In addition to their thermal stability, the fact that these gels are flexible gives them the advantage of deforming and sealing-off multiple and complex near wellbore fractures.The primary objective of this study is to investigate the gelation kinetics of the PAM/PEI cross-linkable polymer to be used in drilling fluids formulations to enhance wellbore stability and strength. Different combinations of polymers and crosslinkers were evaluated; potential polymers were screened for gelation kinetics and gel strength in typical drilling mud formulations. The gelation time of the polymer-based drilling mud formulation is determined in salt-free and in saline systems. The results on rheological properties and gelation kinetics were used to prepare a gelling mud formulation using PAM/PEI cross-linkable polymer as LCM. The produced gel was thermally stable under high-temperature-high-pressure reservoir conditions, which will result in enhanced wellbore strengthening.

Formulation and Characterisation of a Combination Captopril and Hydrochlorothiazide Microparticulate Dosage Form.

Cardiovascular diseases such as hypertension and cardiac failure in South African children and adolescents are effectively managed long term, using a combination treatment of captopril and hydrochlorothiazide. The majority of commercially available pharmaceutical products are designed for adult patients and require extemporaneous manipulation, prior to administration to paediatric patients. There is a need to develop an age appropriate microparticulate dosing technology that is easy to swallow, dose and alter doses whilst overcoming the pharmacokinetic challenges of short half-life and biphasic pharmacokinetic disposition exhibited by hydrochlorothiazide and captopril. An emulsion solvent evaporation approach using different combinations of polymers was used to manufacture captopril and hydrochlorothiazide microparticles. Design of experiments was used to develop and analyse experimental data, and identifyoptimum formulation and process conditions for the preparation of the microparticles. Characterisation studies to establish encapsulation efficiency, in vitro release, shape, size and morphology of the microparticles were undertaken. The microparticles produced were in the micrometre size range, with an encapsulation efficiency >75% for both hydrochlorothiazide and captopril. The microparticulate technology is able to offer potential resolution to the half-life mediated dosing frequency of captopril as sustained release of the molecule was observed over a 12-h period. The release of hydrochlorothiazide of >80% suggests an improvement in solubility limited dissolution.

Castor oil reinforced polymer hybrids for skin tissue augmentation

Polymer hybrids reinforced with castor oil was developed with a combination of different polymers by the freeze-thawing technique. The hybrids in the form of hydrogels were assessed for different physicochemical characterization and in vivo tissue regeneration efficacy. The developed polymer hybrids demonstrated significant cross-linking interaction within the polymer hybrid matrix. In vivo evaluation revealed a superior reepithelialization and skin tissue regeneration efficacy and indicated that the developed polymeric hybrids functionalized with castor oil emulsion could be a potential biomaterial for tissue regeneration.

Effect of low-temperature modifiers on HMA mixture aging and cracking resistance

The Superpave Performance Grade of an asphalt binder can be improved by adding different combinations of polymers and low-temperature modifiers. Although using various modifiers is not new, their effect, in particular softening oils, on long-term aging is not yet well understood. The objective of this study is to evaluate the effect of two widely-used oils to adjust binder grades on volumetrics, workability and fatigue cracking resistance of mixtures subjected to short- and long-term aging. Eight combinations of softening oils and polymers were used to prepare PG 58-34 binders. The mixtures prepared with these combinations were oven-aged for six and 14 h and used to compare their Flexibility Index (FI) results following Semi-Circular Bending Illinois FI test (SCB-IFIT) procedure. In addition, the effects of binder composition and aging on the compaction effort were assessed using the Superpave Gyratory Compactor (SGC) data. Furthermore, extracted and recovered binders of these mixtures were tested following the Linear Amplitude Sweep (LAS) test at intermediate temperature. Overall results indicate that oils used and aging susceptibility of the eight mixtures affected FI results differently. There is a good relationship (R2 = 83%) between the FI values and the absolute value of the LAS-B parameter of the extracted and recovered binders. This finding shows that FI sensitivity to aging is at least initially driven by the binder properties. The main finding from the analysis of the LAS-B parameter is that ΔTc measured for the 20-hr Pressure Aging Vessel (PAV) aging cannot be assumed to represent long-term oven aging of mixtures exceeding six-hours of oven aging at 135 °C.

Formulation of flurbiprofen transdermal patche: In vitro and Ex vivo report

The main aim of this study was to expand the present formulation with patch and to evaluate the transdermal patches of Flurbiprofen, NSAID (Non-Steroidal Anti-Inflammatory Drug) used in the treatment of arthritis. Flurbiprofen is required at a sustained rate of its short half- life (3-4 hours) long term percutaneous absorption is required for its gastrointestinal side effects. Hence in this study, an effort was done to develop transdermal patches of Flurbiprofen by employing a different combination of polymers were prepared by the solvent evaporation technique. Nine formulations were prepared consists of Hydroxy Propyl Methyl Cellulose (HPMC) E15 and polyvinylpyrrolidone in the ratios of 1:1, 1:2. Formulation, HPMC E15 and Ethylcellulose (EC) in 1:1, 1:2. Formulations, HPMC E15 and Eudragit RS100 in 1:1, 1:2, and Formulation HPMC E15 and Eudragit RL100 in 1:1, 1:2.Formulations (F1- F8). F9 formulations contain HPMC E15, Eudragit RS100 in 2:1 ratio with permeation enhancer DMSO 20% v/w of propylene glycol was used as a plasticizer in all the formulations. The developed patches were considered for several physicochemical parameters. In vitro drug release studies showed maximum percentage in 24 hrs for F9 formulation 94.31±1.43, showed maximum Ex-vivo skin permeation of 10,120±0.91 µg/cm2, and the obtained flux meets the required flux. The resultant data was fitted into zero; first, Higuchi and Peppas model and Formulation F9 followed zero order. Drug compatibility studies were resulted by FTIR. The results specify that Flurbiprofen transdermal patch can be designed with the required amount of flux with desire mechanical properties for the cause of better therapeutic benefits.

Photothermal Welding, Melting, and Patterned Expansion of Nonwoven Mats of Polymer Nanofibers for Biomedical and Printing Applications

AbstractWe report a simple method for the photothermal welding of nonwoven mats of electrospun nanofibers by introducing a near‐infrared (NIR) dye such as indocyanine green. By leveraging the strong photothermal effect of the dye, the nanofibers can be readily welded at their cross points or even over‐welded (i.e., melted and/or fused together) to transform the porous mat into a solid film upon exposure to a NIR laser. While welding at the cross points greatly improves the mechanical strength of a nonwoven mat of nanofibers, melting and fusion of the nanofibers can be employed to fabricate a novel class of photothermal papers for laser writing or printing without chemicals or toner particles. By using a photomask, we can integrate photothermal welding with the gas foaming technique to pattern and then expand nonwoven mats into 3D scaffolds with well‐defined structures. This method can be applied to different combinations of polymers and dyes, if they can be co‐dissolved in a suitable solvent for electrospinning.