Advanced Industrial and Engineering Polymer Research最新文献

The circular economy (CE) is facing a problem of industrial implementation. The models are proposed for natural types of polymers and CE. The current work reports the technical strategies and paradigms for sustainable close-loop manufacturing. The post-consumer cotton polymer is used for optimization of functions like cost analysis, material evaluation, recycling technique selection, and quality control. The presentation of the results is advanced by break-even analysis, mechanical testing, tribological investigations, and polymer surface evaluations to select a reasonable processing technique. The current experimental and theoretical approaches could be used functionally for the adaption of the circular economy in polymer industries. The article also highlights the possible procedure for sustainable production of polymer products from natural and artificial wastes.

Polymethyl methacrylate (PMMA) bone cements are used as “glue” between orthopedic/orthodontic implants and bone, since they can be modeled and easily applied by the surgeon, while being chemically and biologically stable for many years after surgery. In this research, Y₂O₃ powder was added to commercial PMMA bone cement to produce a composite resin, which was then characterized and tested in vitro to evaluate the cell proliferation and the quality of osteoblastic bone formed in vitro on the composite. Biological assays showed an increase in cell proliferation on the Y₂O₃-PMMA composite as compared to the pristine sample. Alizarin Red staining (ARS) showed the amount of bone formed on a composite PMMA resin was about 30% higher than that on the pristine PMMA bone cement reference. The quality of bone tissue was evaluated using Raman spectroscopy, showing the bone tissue formed on the composite had a better degree of mineralization and a higher maturity as compared to the tissue grown on the control sample. These preliminary results suggest that Y₂O₃ plays a biologically active role in bone growth and Y₂O₃-composites are affordable, superior candidates as bone cement materials.

The growth in applications of Plantain Fibre Reinforced HDPE (PFRHDPE) has increased the importance of understanding the time-dependent viscoelastic properties such as creep resistance. This study focused on the determination of creep behaviour of a novel PFRHDPE designed for elevated temperatures applications. The creep responses of PFRHDPE were experimentally determined in line with ASTM D2290 and modelled for elevated temperature applications using the classical creep models, classical viscoelastic models and the time temperature superposition approach. Creep strain, creep stress, creep modulus and creep stress relaxation were modelled and analyzed. The PFRHDPE exhibited the characteristic of the unrelaxed and relaxed moduli of material to accommodate applications at elevated temperatures. The superposition method showed PFRHDPE to have moduli of 66 MPa and 2.26 MPa for one year and fifty years of operations respectively. The relaxation stresses were also evaluated as 9.24 MPa, 9.15 MPa and 12.96 MPa for the conditions investigated showing the new material as able to accommodate the constant loads of 25 MPa and 35 MPa under the elevated temperatures of 30 °C and 60 °C.

A novel two-way shape memory polymers derived from benzoxazine/urethane alloys (poly(BA-a/PU)) are developed in this research. The effect of urethane contents acted as spring elastomer on dynamic mechanical properties and two-way shape memory performance of the alloys was investigated. The experimental test and numerical simulation were also used to study and predict the ability of the developed 2WSMPs. The results showed that shape fixity at room temperature (RT) of poly(BA-a/PU) was enhanced in the range of 80–97% with the addition of PU contents. Shape recovery values to first temporary shape at T_g+20 °C of the specimen were 79–93%, whereas, those to second temporary shape at RT were 82–95%. Furthermore, 2WSMP based on poly(BA-a/PU) was reversely recovered between both temporary shapes more than 7 cycles. The experimental and numerical results revealed that poly(BA-a/PU) exhibited high 2WSMP performance for using as smart materials in self-folding structures application.

In several engineering applications, the demand for robust yet lightweight materials have exponentially increased. Additive Manufacturing and 3D printing technology have the scope to make this possible at a fraction of the cost compared to traditional manufacturing techniques. Majority of the previous studies are focused mainly towards the printing parameters namely build orientation, infill density, and layer height etc. Also, most studies considered strength as an output response. However, when it comes to the cellular geometry and nozzle diameter, these parameters were found limited in the literature. Similarly, the combination of output responses such as stiffness, strength, toughness and resilience are found rarely in the previous studies. The current study is designed to capture the said gap in the literature with focus on cell geometry, nozzle diameter and strain rate by using the Taguchi design of experimentation and Grey Relational Analysis. Tensile test results performed on six different patterned samples under ASTM D638 standard suggest that square patterned samples perform the best under tension and retain more mechanical strength than the other five patterns. The grey relational analysis indicates that highest grey relational grade (GRG) was achieved for the larger nozzle diameter of 0.8 mm, strain rate of 5 mm per minute and square cellular geometry. It has been observed that highest contributing factor was nozzle diameter (48.99%), whereas cellular geometry was ranked second with (40.78%) as obtained from analysis of variance (ANOVA). The grey relational analysis simplified the complex 3D printing process optimization.

Volatile organic compounds (VOCs) emission affects the quality of GTR-based materials and might limits their potential applications.

In this work, a brief review VOCs generated during waste rubber management and recycling are highlighted and discussed. A special attention was focused on: i) ground tire rubber (GTR) characteristics; ii) environmental aspects related to GTR applications and iii) GTR degradation and volatile compounds emission.

Analytical information about VOCs emission profile allows more depth understanding of rubber degradation mechanisms, generated low-molecular-weight products and their impact on the environment and human health.

This work confirms that suitable and standardized protocols for qualitative and quantitative VOCs analysis and proper monitoring of selected “markers” (e.g. benzothiazole, limonene, BTEX compounds) can be promising tool for rubber recycling products quality assessment.

This review provides an overview of recycling methods for fluoro-elastomers (FKM) being a very expensive material with excellent properties. However, these properties are based on strong chemical bonds which have to be overcome, but overcome with care to avoid deterioration of the entire polymer. Thus, only two methods could be identified to perform in an industrially acceptable way. The deposition of fine milled fluoro-rubber powder in virgin rubber and the mechanical devulcanization of FKM and successive compounding with virgin rubber have proven to be viable recycling methods providing good thermal stability by maintaining the mechanical properties of original FKM.

In the many countries the main strategy for waste tires utilization is still energy recovery, which use waste tires as low-cost and high-calorific alternative fuel. Although, energy recovery is step forward for suitable waste tires collection and management, it should not be considered as a green and environmentally-friendly method.

Waste tires recycling and upcycling technologies are crucial for further realization of circular economy strategies. Therefore, improvement of already existed and searching for new methods of waste tires industrial applications are fully justified.

In this work, recent advances in development of waste tire rubber-based materials characterized by high content of ground tire rubber (defined as minimum 70 wt%) are presented and discussed. A special attention was focused on the correlation between sustainable treatment or functionalization of waste tire rubber and the structure–property relationships of the prepared materials.

Moreover, the main problems and challenges affecting the possible industrial application of materials highly modified by waste tire rubber are also highlighted.

The absorption of aroma compounds in seals during the bottling of wine and the migration of these aroma compounds into the subsequent bottling process is a major problem in the German wine industry. In order to meet the legal requirements, for example, the seals used up to now have to be replaced with more expensive alternatives. However, these alternatives are not suitable for every area of application. An alternative to this is the use of modified ethylene-propylene-diene-rubber seals, which have a lower aroma compound carry-over. In a research project, new and inexpensive ethylene-propylene-diene-rubber seals were developed which minimise migration into the subsequent filling process. The seal material and the surface of the seals were modified. Within the scope of the research, compounds of different fillers were prepared and examined for their migration properties of critical aroma compounds. Furthermore, the influence of the degree of crosslinking, the ethylene content of the basic rubbers used, the plasticisers used and the influence of the surface roughness of the seals were also examined. The seals were coated using low-pressure plasma in order to describe the migration of selected aroma compounds depending on the surface properties. In addition to the migration properties, the influence of the fillers used on mechanical properties such as elongation at break and compression set was also measured, since seals have to fulfil a wide range of requirements. By means of statistical test planning, the observation was carried out in effect and contour diagrams in order to create an optimised sealing material on the basis of the resources used.