Polymers containing hydrogen-bonding side groups (HBGs) can form transient supramolecular networks that exhibit technologically useful viscoelastic properties. Here, we investigate how dynamic behavior of functional poly(n-butyl acrylate) melts and cross-linked is influenced by different HBGs. Random copolymers weak strong HBGs were synthesized subjected to thermal mechanical analysis. The glass transition temperature (Tg) increased nearly linearly with the HBG concentration, this effect was...

Describes how decentralized control theory can be used to analyze the of multiple cooperative robotic vehicles. Models cooperation are discussed and related input/output reachability, structural observability, controllability entire system. Whereas research in past has concentrated on using controllers partition complex physically interconnected systems, this work uses methods connect otherwise independent nontouching vehicles so that they behave a stable, coordinated fashion. A vector...

Superconducting rotating machines have looked promising since multifilamentary niobium-titanium (NbTi) superconductors became available in the mid-1960s. Both dc homopolar and ac synchronous were successfully tested from 1970s to 1990s. Three different 70-MW generators recently demonstrated by SuperGM project Japan. However, economic considerations with respect competitive cost combined requirement for liquid helium cooling did not make these commercially attractive. On other hand,...

Here, we report on a polymer blend consisting of soft thermoplastic polyurethane (TPU) elastomer and low melting temperature healing agent (polycaprolactone, PCL). In this study, blends containing up to 60 wt % PCL were prepared the resulting mechanical, thermal, shape memory, self-healing properties studied. These immiscible polymers exhibit two well-separated transitions attributable TPU hard segments. This viscoelastic behavior engendered memory capability at moderate processing...

The field of tissue engineering has made significant advancements with extrusion-based bioprinting, which uses shear forces to create intricate structures. However, the success this method heavily relies on rheological properties bioinks. Most bioinks use shear-thinning. While a few component-based efforts have been reported predict viscosity bioinks, impact rate vastly ignored. To address gap, our research presents predictive models using machine learning (ML) algorithms, including...

With the increasing use of biodegradable plastics in agriculture and food packaging, it has become increasingly important to assess effects their fragmentation mineralization environment (i.e., soil, compost). PBAT is a polyester widely used mulch films that are intended fragment mineralize soil. To study these effects, novel methodologies needed quantify microplastics diverse environments. This work seeks answer whether gas chromatography mass spectrometry (GCMS) can be as tool A method was...

Controlling network architecture and chain connectivity is critical to understanding elastic energy storage improving performance of shape-memory polymers. Acrylate-terminated poly(caprolactones) were converted into thermoset networks by three different reactions: conventional free radical polymerization, radical-induced coupling with multifunctional thiols, base-catalyzed Michael addition thiols. The highly efficient thiol–acrylate reaction ensures that the molecular weight between...

Cross-linked elastomers containing reversibly binding side groups are capable of storing elastic energy on multiple time-scales, giving rise to shape-memory and self-healing properties. Photo-cross-linkable benzophenone were incorporated into linear macromers reversible (2-ureido-4-pyrimidinone, UPy) groups. This method enables melt-processing complex permanent shapes, samples can be prepared with much higher UPy-content. UV–vis spectroscopy was applied study the efficacy cross-linking...

This paper studies the degree to which kinematic redundancy of a manipulator may be utilized for failure tolerance. A redundant is considered fault tolerant with respect given task if it guaranteed capable performing after any one its joints has failed and locked in place. method developed determining necessary constraints insure tolerance kinematically critical task. based on estimating bounding boxes enclosing self-motion manifolds set points. The intersection these provides artificial...

In this report the swelling and linear viscoelastic behavior of a hydrophilic polymer containing reversibly associating hydrogen bonding side-groups will be examined. Ureidopyrimidinone (UPy) moieties self-associate to form hydrogen-bonded dimers (DDAA) in non-polar media; however, UPy water-swollen hydrogel environments is unclear. A series technologically important, poly(hydroxyethyl methacrylate) (poly(HEMA)) polymers, with varying side-group content, were prepared using reversible...

Research into the 3D printing of self-healing polymers has increased; however, understanding regarding relationship between (3DP) parameters, material composition, and their impact on resulting properties remains limited. In this work, we examine how composition affects 3DP, thermal, mechanical, an extrinsically resin system based linear polycaprolactone (PCL) as a healing agent. The polymer is 2-phenoxyethyl acrylate (POEA) 1,6-hexanediol dimethacrylate (HDDMA) with up to 25 wt % PCL. Upon...

Fixing chain orientation within polymeric materials can impart anisotropic mechanical, optical, and electrical properties. Although macroscopic anisotropy in amorphous or liquid crystalline phases has been achieved by cross-linking thermoreversible bond shuffling under strain, these methods lack spatial temporal resolution. Here, we demonstrate a method to controllably write into polymer networks containing both permanent light-sensitive bonds. While held mechanical stress light initiates...

The goal of this study was to identify and quantify complications occurring with the administration anesthesia for dental treatment patients special needs. Anesthesia providers completed a standardized evaluation form, delineating possible 202 consecutive ambulatory receiving in needs clinic. Statistical analysis four types administered showed that overall complication rate 23.8%. Evaluation data were considered either mild (95.8%), or moderate (4.2%), while no reports severe occurred....

Relating thermoreversible bond kinetics to temperature and mechanical stress is essential for the ongoing development of melt-processable, reconfigurable networks. Here, we apply dynamic analysis methods study equilibrium behavior polymer networks above their gel point. Thermoreversible Diel–Alder (DA) adducts are installed as linking groups create well-defined poly(caprolactone) Stress relaxation studies at various strains performed differentiate how influence rate breaking, i.e., retro-DA...

The use of biodegradable plastics is increasing as customer expectations toward sustainability are addressed. However, their biodegradation processes, mechanisms, and dynamics in real applications still not well understood. Commonly available analytical techniques such differential scanning calorimetry (DSC) Fourier transform infrared spectroscopy can help to better understand the kinetics different environments, e.g., home compost, industrial soil. Polymer fragmentation, mainly through...

This paper formulates an algorithm for trajectory generation two robots cooperating to perform assembly task. Treating the as a single redundant system, this derives Jacobian matrices which relate joint rates of entire system relative motion grippers with respect one another. The main advantage method over previous methods is that operations may be described in coordinates rather than world coordinates. To join parts using algorithm, desired position specified and automatically determines...