A numerical model is presented to simulate the crystallization kinetics in fiber-based composite with thermoplastic semicrystalline matrix. The proposed model, based on Schneider's formalism, considers specificity of crystalline entities growing confined medium such as fibrous composite. Indeed, transcrystallization has been experimentally observed many times and its effects both mechanical pro...

Two major factors hampering the broad use of rapid prototyped biomaterials for tissue engineering applications are the requirement for custom-designed or expensive research-grade three-dimensional (3D) printers and the limited selection of suitable thermoplastic biomaterials exhibiting physical characteristics desired for facile surgical handling and biological properties encouraging tissue int...

The goal of this study was to evaluate the thermoplasticity of conventional and thermoplastic gutta-percha and Resilon, a polyester polymer-based material. Specimens with standardised dimensions were made from the following materials: conventional and thermoplastic gutta-percha (Dentsply), conventional and thermoplastic gutta-percha (Endopoints) and Resilon. After 24 h, the specimens were place...

Thermoplastic polyamide elastomer (PAE) [also PEBA: polyether block amide] is one of the most recently developed of the thermoplastic elastomers: a multiblock polymer with polyamide hard segments, it uses longchain polyether diol or polyester diol of low Tg for its soft segments. Polyamide 6 or polyamide 12 (PA12) is the main polyamide component used, while the soft segments are mostly provided...

Fast layup and in-situ consolidation capabilities had allowed thermoplastic tape placement techniques to gain considerable appreciation in aerospace and automobile industries. Extensive research had been carried out side by side in theoretical and experimental aspects to realize a tape placement head for producing components with ideal mechanical properties [1]. Experimental parametric studies ...

This paper presents the findings of an initial study of the fabrication of polyetheretherketone (PEEK) components based on the mask-image-projection-based Stereolithography (MIP-SL) process. PEEK is a semicrystalline thermoplastic with excellent mechanical and chemical resistance properties that are retained to high temperatures. It has been extensively used in the aerospace, automotive, biomed...

A pre-consolidated thermoplastic advanced composite cross-ply sheet comprised of two uniaxial plies orientated at 0/90 has been thermoformed using tooling based on the double-dome bench-mark geometry. Mitigation of wrinkling was achieved using springs to apply tension to the forming sheet rather than using a friction-based blank-holder. The shear angle across the surface of the formed geometry ...

In this work, electrically conductive cellulose nanocrystals were used to reinforce shape memory polyurethanes, adding an extra variable to tune up the properties of these nanocomposites. The modified nanocrystals were prepared by an in situ polymerization method, growing polyaniline (PANI) on the surface of the cellulose nanofibrils [3]. These crystals combine the good mechanical properties of...

Dens invaginatus is a rare developmental anomaly of teeth with complex root canal system morphology. The present case describes a peg shape maxillary lateral incisor with dens invaginatus (Oehlers type II), necrotic pulp, and an associated large periradicular lesion. Nonsurgical endodontic treatment was performed with the aim of removing the blind sac with diamond bur under the use of operating...

In this paper, the fabrication and characterization of triple-shape polymeric composites (TSPCs) that, unlike traditional shape memory polymers (SMPs), are capable of fi xing two temporary shapes and recovering sequentially from the fi rst temporary shape (shape 1) to the second temporary shape (shape 2), and eventually to the permanent shape (shape 3) upon heating, are reported. This is techni...