Advanced Industrial and Engineering Polymer Research最新文献

The exhaustion of available natural resources and rising concerns about the environment have prompted a growing desire to discover innovative ways to produce environmentally friendly materials. In an effort to alleviate environmental issues connected to the disposal of agricultural waste, many studies have engaged on research pertaining to agricultural waste management. Every year, there are enormous amounts of agro based waste created, which is a major issue from an economic and environmental standpoint. These wastes can be utilized as secondary raw materials to create value-added products in accordance with the circular economy's guiding principles. The exploitation of natural agricultural wastes has become critical for the development of sustainable biopolymer-based composites for lightweight applications. To this extent, this review presents an overview of the development and utilization of agricultural wastes to create biopolymers building blocks to be coupled with natural reinforcements for the fabrication of sustainable bio composites for lightweight applications. Common agricultural derived biopolymers are discussed. This review also highlights major bio composite fabrication methodologies and potential applications including challenges and opportunities in the development of sustainable biopolymer-based composites from agricultural waste biomass. It was concluded that the development of sustainable biopolymer-based composites from agricultural biomass offers a promising route towards a more environmentally friendly future.

Magnesium (Mg) & its alloys are favourable for orthopaedic & cardiovascular medical device fabrication applications, but holds a natural ability to degrade biologically when put with aqueous solution of the substances and/or water-saturated tissue in the context of a living organism. Mg alloys nature to corrode inside the living organism body is mainly attributed to the excessive rates of corrosion of Mg. Poor corrosion resistance possessed by Mg decreases the mechanical properties of the implants, and adds toxic effects on the bone metabolism. A potential method for increasing Mg alloy resistance to corrosion without changing its properties is by the protective polymeric deposit coatings. Moreover, to impart better mechanical and biocompatible aspects to Mg based materials biopolymers have been used as a composite constituent. This review is based on such composite materials constituting Mg and biopolymers. Their resulting favourable mechanical and osteopromotive properties in conjunction with biocompatibility may help the clinicians to fix the existing orthopaedic related issues.

Due to the deleterious environmental consequences resulting from a broad spectrum of synthetic polymers during use or post-application disposal, interest in biomaterials obtained from eco-friendly and sustainable sources is growing. This review first examines some of the fundamental concepts regarding biologically-derived nanoparticles (“bionanoparticles”) extracted from the two most prevalent polymers on the planet: natural cellulose and chitin. With this background established, we turn our attention to several advances in this expanding field. Recent rheological studies have established that a “kink” often reported in steady-shear tests of fibrous nanocellulose suspensions is related to anisotropic flocs. Thorough analysis of this observation demonstrates the existence of dual yield points that pinpoint the processing conditions over which these flocs form. Another advance is isothermal titration calorimetry, which relates the formation of structure to viscous heating and provides a uniquely quick and precise analysis tool for measuring the concentration of cellulose nanocrystals responsible for the onset of mesomorphism in aqueous suspensions. In addition, the incorporation of various electrolytes in aqueous nanocellulose or nanochitin suspensions is capable of promoting cellulose or chitin nanocrystal (de)swelling or suspension templating of solid films, and positron annihilation lifetime spectroscopy can be used to follow changes in nanoscale free volume upon swelling in the presence of moisture, which can be independently used in conjunction with CO₂-philic ionic liquids to achieve highly selective carbon capture in hybrid gas-separation membranes.

Polymer-based drug delivery systems have been extensively studied for decades. These systems must be degradable, capable of controlling drug release kinetics, and of reaching a precise target organ. While degradability is an intrinsic property of the material, controlled and targeted drug delivery is achieved with proper system design. The Molecular Imprinting technique can be used successfully to control the drug release kinetics and to achieve drug targeting. To date, the literature reports a very limited number of studies related to molecularly imprinted polymers for nanomedicine. The lack of applications is mainly due to the difficulties of obtain degradable materials with this technique. The present review reports a summary of the applications and characteristics of molecularly imprinted polymers, with a focus on their potential in nanomedicine. The advantages of their use and any limitations will be highlighted. Finally, the applications of the molecular imprinting technique, developed so far, to the preparation of degradable materials will be reported.

One of the most widespread versions of additive manufacturing technologies (AM) is fused filament fabrication (FFF) or fused deposition modeling (FDM), using polymer melts to print freeform structures. Due to specific rheological and processing conditions, interlayer adhesion, shrinkage, and warpage problems, standard polymer grades do not always meet all requirements, so more polymers must be combined to achieve the optimum solution. These combinations include traditional blending technologies (with or without compatibilizer additives), reactive extrusion, and mixing incompatible phases with mechanical interlocking. Combining layers of different polymers in laminated structures, improving the interlayer strength of one-component prints, and developing core-shell filaments also require solving compatibility problems. This mini-review shows representative examples from blending engineering polymers, high-performance polymers, multilayer and coextruded structures, and biodegradable polymers and discusses the solutions characterizing the extrusion-based additive manufacturing technologies, which sometimes differ from multicomponent materials used in injection molding.

The recent interest in multifunctional materials with tailorable performances led to the formulation of novel polymer blends, with enhanced properties with respect to traditional plastics and showing economical advantages compared to the synthesis of new polymers. However, polymer blends are immiscible in most cases, and proper compatibilization is therefore needed to obtain an alloy with suitable performances. Beside the traditional compatibilization approaches (i.e., addition of graft or branched copolymers, reactive compatibilization), a novel technique has recently emerged, based on the insertion of micro- and nanostructured inorganic fillers within polymer blends.

Therefore, the aim of this review is to give an overview about the role played by nanofillers on the compatibilization of polymer alloys. A survey of the most important papers in literature on this topic will be presented, trying to correlate the microstructural features of nanofilled blends to their physical properties. After an introduction on the general aspects of polymer alloys in Chapter 1, the most relevant compatibilization strategies will be presented in Chapter 2, with particular emphasis on the compatibilization induced by micro- and nanostructured fillers. Chapter 3 will be focused on the nanofiller induced compatibilization, and several examples of thermoplastic, thermosetting and elastomeric nanofilled blends will be presented. Considering the increasing importance of biopolymers and of their blends in the modern industry, in Chapter 4 it will be shown how nanofiller induced compatibilization could be successfully applied also to bioplastics based alloys. Due to the recent environmental concerns on the polymer waste management and the difficulties in the plastics sorting operations, in Chapter 5 it will be demonstrated that nanomodification of recycled plastics can lead to blend recyclates with good compatibility and suitable physical properties. The key aspects of the nanofiller induced compatibilization in polymer blends and the future perspectives will be summarized in Chapter 6.

Waste tires are a low-cost and high-calorific alternative fuel, therefore energy recovery is still very popular method of their utilization. On the other hand, waste tires are composed from high quality components and can be considered as valuable source of raw materials. Recent trends showed that further development of waste tire recycling technologies and waste tire rubber based materials are crucial to design the cradle-to-cradle loops for elastomer products. This approach fits to circular economy concept, however high content of waste tire rubber in various polymer blends or composites usually results in deterioration of their processing and/or the performance properties. Some of those technological issues can be resolved by choose suitable compatibilization method.

This work summarizes recent advances in the compatibilization strategies dedicated for polymer/waste tire rubber systems prepared via a simple melt-blending, including: i) optimization of processing conditions; ii) GTR particle size and oxidation; iii) devulcanization/reclaiming; iv) reactive blending and v) other methods. Furthermore, the limitations and challenges related to further development of thermoplastic composites and thermoplastic elastomers based on GTR are also highlighted.

The paper focuses on the necessity for compatibilization in polymer blends and composites due to the differing chemical nature of the components, which causes antagonism on the contacting surfaces. To achieve stable polymer blends and composites with the correct set of properties, this thermodynamically driven antagonism must be smoothed because it may result in dephasing. Typically, this is accomplished by including a third component, a compatibilizer. The review focuses on compatibilization strategies based on component peculiarities, that is, without the addition of a specially synthesized third component. They include the ability of components to participate in chemical interactions such as additional condensation and transreactions, hydrolytic reactions or hydrogen bonding, or the production of co-crystals and transcrystalline layers. Finally, single polymer composites are discussed as a case where compatibilization is not required.

The sustainable processing of recycled products requires veritable testing during quality control for commercial application. In this research work, mechanical (ASTM D3039), compression (ASTM D5467) and impact (ASTM A370) are utilized to observe the usability, diversity, and suitability of the developed polypropylene-postconsumer cotton fibers (PP-PCCF) composites for industrial applications. The cotton waste was ground using a grinding machine. The ground fibers were introduced to manufacture composites from 0 to 40% fiber loading variations. The fine cotton fibers and synthesized composites were characterized by scanning electron microscope before and after mechanical testing. The fiber length, diameter and area were in the range of 2.5 mm–5.5 mm, 12.5 μm–22 μm and 200.15 μm²–250.50 μm², respectively. The engineering and design values were tensile strength (31.16 MPa–22.77 MPa), breaking strength (26.69 MPa–22.77 MPa), modulus of elasticity (2223.79 MPa–2770.77 MPa), and extension (17.48–3.21). Similarly, flexural strength, modulus, energy, and fracture force are also enhanced with an increase in fiber loading. The impact energies of pure polypropylene and PP-PCCF composites (with 10, 30, and 40% PCCF contents) were 50 kJ/m², 48 kJ/m², 43 kJ/m², and 58 kJ/m². The micrographs of PP-PCCF composites prove that the density of voids is enhanced with an increase in fiber contents. The PP-PCCF composites with 0%–30% fiber loadings showed minimum defects and were observed to be suitable for structural applications. On the other hand, the PP-PCCF composites with 30%–40% fiber loading are acceptable for environmental applications.

This paper explores the potential of using Chat Generative Pre-trained Transformer (ChatGPT), a Large Language Model (LLM) developed by OpenAI, to address the main challenges and improve the efficiency of the Gcode generation process in Additive Manufacturing (AM), also known as 3D printing. The Gcode generation process, which controls the movements of the printer's extruder and the layer-by-layer build process, is a crucial step in the AM process and optimizing the Gcode is essential for ensuring the quality of the final product and reducing print time and waste. ChatGPT can be trained on existing Gcode data to generate optimized Gcode for specific polymeric materials, printers, and objects, as well as analyze and optimize the Gcode based on various printing parameters such as printing temperature, printing speed, bed temperature, fan speed, wipe distance, extrusion multiplier, layer thickness, and material flow. Here the capability of ChatGPT in performing complex tasks related to AM process optimization was demonstrated. In particular performance tests were conducted to evaluate ChatGPT's expertise in technical matters, focusing on the evaluation of printing parameters and bed detachment, warping, and stringing issues for Fused Filament Fabrication (FFF) methods using thermoplastic polyurethane polymer as feedstock material. This work provides effective feedback on the performance of ChatGPT and assesses its potential for use in the AM field. The use of ChatGPT for AM process optimization has the potential to revolutionize the industry by offering a user-friendly interface and utilizing machine learning algorithms to improve the efficiency and accuracy of the Gcode generation process and optimal printing parameters. Furthermore, the real-time optimization capabilities of ChatGPT can lead to significant time and material savings, making AM a more accessible and cost-effective solution for manufacturers and industry.