Why we Need a Heated Chamber for 3D Printing with ‘High Performance’ Polymers?

This paper is dedicated to the features of the processes of 3D printing of polymers with a high melting point such as PEEK, CarbonPEEK, ULTEM, PPSU using FDM (FFF) technology. The results of 3D printing with high-performance polymers using different conditions of the heated chamber are presented. Conclusions about the advantages of a heated chamber are made.

Strain Induced by Bio-High-Performance Polymers and Cobalt-Chromium Digitally Constructed Telescopic Partial Dentures after 1 Year Simulation of Function

BACKGROUND: Numerous attempts were made to reduce the adverse effects of the distal extension removable partial dentures (RPDs) and enhance their prognosis. High-performance polymers (HPP) were utilized in the construction of RPDs to maintain the health of the supporting structures. AIM: Thus, this study was prompted to compare the strains induced by Bio HPP and Cobalt- Chromium (Co Cr) Computer Assisted Design and Computer Assisted Manufacturing telescopic RPDs after 1 year of function. MATERIALS AND METHODS: A maxillary Kennedy class I was used in this study. Twelve telescopic RPDs were fabricated from two different materials. In Group A, six telescopic RPDs were milled from Co-Cr and in Group B, six telescopic retained RPDs were milled from Bio-HPP. Each partial denture was seated on the cast and introduced into the chewing simulator. The strain values were recorded using four strain gauges connected to a four-channel strain indicator. Statistical analysis of the resultant data was done using one-way ANOVA, followed by Tukey’s HSD for comparison within the same group. Student t-test was used for comparison between the different groups. The significance level was set at p ≤ 0.05. RESULTS: During unilateral loading, the results showed higher strains in Group A at the abutments (473.33 μm/m ± 10.8, 193.39 μm/m ± 10.8) and at the distal aspect of the ridge (470.83 μm/m ± 13.93, 185 μm/m ± 20.83) than Group B. Independent t-test showed statistically significant difference between strains at the abutments of both groups (t = 70.4, p ≤ 0.0001), (t = 36.84, p ≤ 0.0001). Furthermore, there was a statistically significant difference between strains at the saddles of both groups (t = 51.62, p ≤ 0.0001), (t = 34.72, p ≤ 0.0001) respectively (DOF = 10). CONCLUSIONS: In telescopic RPDs, Co Cr induces higher strain values on the abutments and the distal aspect of the ridge than Bio-HPP during bilateral and unilateral loading. During unilateral loading, Bio-HPP telescopic RPDs direct high strain values on the distal aspect of the ridge of the loaded side. CLINICAL IMPLICATIONS: The materials that induce less stresses on the supporting structures of telescopic partial dentures on the long-term can be used to maintain the health of periodontally affected abutments.

Homogeneous Catalyzed Valorization of Furanics: A Sustainable Bridge to Fuels and Chemicals

The development of efficient biomass valorization is imperative for the future sustainable production of chemicals and fuels. Particularly, the last decade has witnessed the development of a plethora of effective and selective transformations of bio-based furanics using homogeneous organometallic catalysis under mild conditions. In this review, we describe some of the advances regarding the conversion of target furanics into value chemicals, monomers for high-performance polymers and materials, and pharmaceutical key intermediates using homogeneous catalysis. Finally, the incorporation of furanic skeletons into complex chemical architectures by multifunctionalization routes is also described.

Crosslinked Fluorinated Poly(arylene Ether)s with POSS: Synthesis and Conversion to High-Performance Polymers

This study reports on a series of crosslinked poly(arylene ether)s with POSS in the main chain. The fluorinated and terminated poly(arylene ether)s were first synthesized by the nucleophilic reaction of diphenol POSS and decafluorodiphenyl monomers, including decafluorobiphenyl, decaflurobenzophenone, and decafluorodiphenyl sulfone. They were then reacted with 3-hydroxyphenyl acetylene to produce phenylacetylene-terminated poly(arylene ether)s. The polymers were of excellent processability. When heated to a high temperature, the polymers converted into a crosslinked network, exhibiting a low range of dielectric constant from 2.17 to 2.58 at 1 HMz, strong resistance against chemical solutions, low dielectric losses, and good thermal and hydrophobic properties.