Physical, Chemical, and Thermal Analysis of Thermoplastic Resins

This article addresses some established protocols for characterizing thermoplastics and whether they are homogeneous resins, alloyed, or blended compositions or highly modified thermoplastic composites. It begins with a discussion on characterizing mechanical, rheological, and thermal properties of polymer. This is followed by a section describing molecular weight determination using viscosity measurements. Next, the article discusses the use of cone and plate and parallel plate geometries in melt rheology. It then reviews the processes involved in the analysis of thermoplastic resins by chromatography. Finally, the article covers three operations of thermoanalysis, namely differential scanning calorimetry, thermogravimetric analysis, and thermomechanical testing.

Research Progress of Wood-Based Panels Made of Thermoplastics as Wood Adhesives

When thermoplastic resins such as polyethylene (PE) and polypropylene (PP) are selected as wood adhesives to bond wood particles (fibers, chips, veneers) by using the hot-pressing technique, the formaldehyde emission issue that has long existed in the wood-based panel industry can be effectively solved. In this study, in general, thermoplastic-bonded wood-based panels presented relatively higher mechanical properties and better water resistance and machinability than the conventional urea–formaldehyde resin-bonded wood-based panels. However, the bonding structure of the wood and thermoplastic materials was unstable at high temperatures. Compared with the wood–plastic composites manufactured by the extruding or injection molding methods, thermoplastic-bonded wood-based panels have the advantages of larger size, a wider raw material range and higher production efficiency. The processing technology, bonding mechanism and the performance of thermoplastic-bonded wood-based panels are comprehensively summarized and reviewed in this paper. Meanwhile, the existing problems of this new kind of panel and their future development trends are also highlighted, which can provide the wood industry with foundations and guidelines for using thermoplastics as environmentally friendly adhesives and effectively solving indoor pollution problems.

Additive Manufacturing of Thermoplastic M8 Fasteners Using Photopolymer Jetting Technology for Low-Strength Fastening Applications

This study investigates the spatial accuracy of additively manufactured M8 fasteners fabricated using photopolymer jetting technology. A number of M8 bolts and their mating M8 nuts are fabricated using Stratasys Object 260 Connex 3 polyjet printer with Vero cyan, Vero magenta, Vero white, and Vero grey thermoplastic resins. Vero series thermo-plastics were used as they offer durability, strength, and flexibility. The additively manufactured nuts and bolts are fabricated with the intention of introducing thermoplastic fasteners that could eventually substitute metal fasteners in certain low strength joining applications such as in fluidics, electronics, biomedical engineering, food packaging, and automobile industries. Manufacturing constraints and critical conditions for fabrication are presented. Vital printing and manufacturing constraints, dimensional stability analysis, and the subsequent dimensional changes for the fabricated fasteners are thoroughly illustrated. Dimensional stability of the printed structures was examined under an ultra-compact 3D laser sensor and the imaging results are also presented. The fabricated thread profile superimposed precisely with the CAD model’s ISO thread profile dimensions. The dimensional performance of the fabricated M8 fasteners was examined in every orientation and along each axis of the fasteners. The high-quality manufacturing of fasteners using photopolymer jetting reached the maximum precision requirements and fitted under IT 06 transition fit grade.

JUSTIFICATION OF THE APPLICATION OF CONSTRUCTION MATERIALS IN THE PHENOMENA OF INTOLERANCE TO ACRYLATES

Introduction. Today, for the manufacture of prostheses with a plastic base, hot polymerization acrylic plastic is most often used, which contains a free monomer — methyl methacrylate. However, in some patients, after their placement in the oral cavity, as a result of orthopedic treatment, various clinical pathological manifestations may occur, which in general are defined as individual intolerance to dental materials. The aim is to carry out a systematic analysis of domestic and foreign literary sources to determine the most suitable base material in patients with intolerance to structural materials. Methodology. The research was carried out on the basis of the search for scientific papers, in the electronic scientific library elibrary.ru for the last 15 years, as well as in the search engines PubMed, Scopus and Wiley Inter Science for 2009–2020. The search was carried out by keywords. Results. The article analyzes the literature data indicating the importance of the choice of the base material in the pathogenesis of intolerance to dental materials. During the analysis of the literature, the positive properties of a new, alternative light-curing base material, which can be used in patients with acrylate intolerance, have been substantiated. Conclusions. The results obtained, in the course of the literature analysis, allow us to highlight the advantages of using a light-curing base material in comparison with acrylic plastics and thermoplastic resins. The results of the use of the light-curing base material in clinical practice will be communicated by us to the dental community in subsequent publications.

A Research on The Formability of PVC Sheet in Single Point Incremental Forming (SPIF) Technology

Nowadays Single Point Incremental Forming (SPIF) is really a new technology of forming metal sheet after its formation and long development in about five decades. Although it was invented in, 1967 by Leszak, an American inventor, but the applications of the innovative technology have just been popular from 1990 because of the advance of controlling technology. This technology is especially adapted to small batch, unique or single productions. In almost all cases, the workpiece material sheets are metal such as aluminum alloys, bronze, mild steel, stainless steel and even Titanium with lot of researches, papers and thesis... Nonmetal sheets are rarely applied in this technology because of rare application. Nowadays, on the rise of the development of composite materials such as, PVC, thermoplastic resins... that have been a lot of applications on living life and technology. In this paper, we dedicate all of our work in the examination some parameters of forming that influence on the deformable ability of PVC plastic by empirical method under the support of DOE and Minitab software. This paper also provides our own experiences in forming PVC sheet that we had performed in the recent decade.

Experimental Study on Smoke Production and Smoke Generation in Thermoplastic Resins Based on PP, PMMA, and PVC

Due to the complexity and large size of buildings, plastic resin is widely used as a building material. Accordingly, the occurrence of fires caused by plastics is increasing. Due to the nature of plastic resin fires, the amount of damage to properties and human life caused by combustion products such as smoke are large, and these damages are related to smoke production and smoke generation. Therefore, this study reviews smoke measurement methods and laws on domestic buildings and fire services. Experiments were conducted based on three smoke-related test standards (ISO 5660-1, ISO 12136, ASTM E 662). The experiment results indicate a total smoke production and generation by PP, PVC, and PMMA of 43.27, 32.83, and 12.33 m2, and 27.855, 9.599, and 6.975 g, respectively.

Polypropylene/Basalt Fabric Laminates: Flexural Properties and Impact Damage Behavior

Recently, the growing interests into the environmental matter are driving the research interest to the development of new eco-sustainable composite materials toward the replacement of synthetic reinforcing fibers with natural ones and exploiting the intrinsic recyclability of thermoplastic resins even for uses in which thermosetting matrices are well consolidated (e.g., naval and aeronautical fields). In this work, polypropylene/basalt fabric composite samples were prepared by film stacking and compression molding procedures. They have been studied in terms of flexural and low-velocity impact behavior. The influence related to the matrix modification with a pre-optimized amount of maleic anhydride grafted PP as coupling agent was studied. The mechanical performances of the composite systems were compared with those of laminates consisting of the pure matrix and obtained by hot-pressing of PP pellets and PP films used in the stacking procedure. Results, on one side, demonstrated a slight reduction of both static and dynamic parameters at the break for specimens from superimposed films to ones prepared from PP pellets. Moreover, an outstanding improvement of mechanical performances was shown in the presence of basalt layers, especially for compatibilized samples.