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The degradation behavior of P(TMC-co-CL) in different compositions was investigated via subcutaneous implantation in vivo. To clarify the role of enzymes in the degradation behavior of the copolymers, hydrolytic and enzymatic degradation were also performed. The mass loss, changes in molecular weight and polydispersity, as well as the variation in composition were monitored with degradation. The changes...
In the present study, the feasibility of Friction Spot Welding (FSpW) of a commercial-grade poly(methyl methacrylate) (PMMA) (PMMA GS) and PMMA 6N/functionalized silica (SiO2) nanocomposites was investigated. The silica nanoparticles were functionalized via atom transfer radical polymerization (ATRP) with PMMA chains to achieve a uniform dispersion in the polymer matrix. The successful functionalization...
Most studies on surface-initiated controlled polymerizations for the synthesis of polymeric covalent organic-inorganic hybrid materials focus on chemical methods requiring specific modifications of the inorganic substrate. Few mechanistically-aware approaches have been undertaken towards exploiting the reactivity of defects induced by physical techniques such as ionizing radiations or UV–Vis light...
We prepared the novel fluorescent polymer latex particles which can change their fluorescence intensity in response to the increasing NaCl concentration in water. Core polymer latex particles were synthesized by emulsifier-free emulsion polymerization of styrene and 2-(2-chloroisobutyroyloxy)ethyl methacrylate. Hydrophilic polymer chains containing epoxy groups were grafted from the core particles...
Composite fabrication techniques predominantly involve wet-synthetic protocols with organic solvents. While the resulting composite exhibits good electrical properties, their mass-production have been severely hindered due to use of excessive organic solvents. In contrast, dry-compounding methods are well-suited for industrialization but result in composites with lower electrical properties. This...
The crystal structure and morphology of poly(ether ether ketone) (PEEK) was investigated using standard differential scanning calorimetry (DSC), flash DSC, optical microscopy, atomic force microscopy, and small angle X-ray scattering tools. The flash DSC results suggested that the double melting peaks phenomenon observed in conventional DSC work originated from the reorganization of PEEK crystals,...
The structure and molecular weight of the hyperbranched polyesterification of adipic acid and glycerol were characterized by 13C NMR spectroscopy and size-exclusion chromatography as a function of reaction time and reaction stoichiometry. The glycerol substitution patterns and the extent of reaction of both glycerol and adipic acid were determined by NMR. The glycerol species concentrations determined...
Polymer/reduced graphite oxide (rGO) composite nanoparticles with a high electrical conductivity were synthesized using the miniemulsion polymerization technique. The rGO was modified with a reactive surfactant, 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS), to facilitate monomer intercalation into the rGO nanogalleries. The AMPS-modified rGO was emulsified in the presence of styrene (St) and...
Nanocomposites of biobased thermoplastic polyurethane (TPU) from dimer fatty acids and halloysite nanotubes (HNT) were elaborated by different melt processing routes such as direct mixing (1 step process) and masterbatch/dilution (2 steps process), at different temperatures (150 and 180 °C). Rheological and transmission electron microscopy (TEM) analyses indicated that the HNT distribution and dispersion...
It is well known that acidity, pH, of a solution accelerates the hydrolysis of soluble amides. Here we describe the unexpected result that weak small organic acids at low concentrations hydrolyze a polyamide at rates approximately twice that of a water HCl solution of the same pH. The effect of three small organic acids in dilute solutions, acetic, propanoic, and butanoic was studied. It is observed...
The adsorption of cations and anions in nitrate solutions on N,N-dimethyl(acrylamidopropyl)ammonium propane sulfonate (DMAAPS) gels prepared using various cross-linker and monomer concentrations was investigated. The influence of the temperature and nitrate concentration on the adsorption properties of the gel was evaluated, demonstrating simultaneous adsorption of cations and anions. The amount of...
The main focus of this research is to identify the structural mechanisms that are responsible for changes observed in various stages of coupled mechano-optical (stress and strain optical) relationships as they are influenced by the deformation mode, level and rate. This involves in situ real time studies of the true-stress-strain-birefringence of sequential biaxially stretched PET films using a highly...
A homogenous polycarbonate/cyanate ester network has been prepared from a renewable, eugenol-derived bisphenol. The pure polycarbonate exhibited a Tg of 71 °C, Mn = 8360, and polydispersity of 1.88. An 80:20 blend of cyanate ester: polycarbonate was prepared and thermally cured. The presence of the polycarbonate had no significant effect on the cure behavior of the cyanate ester. Small Angle Laser...
Melt electrospinning writing (MEW), a computer-aided fiber deposition process based on an electrohydrodynamic working principle, enables the rational design and fabrication of fibrous scaffolds with micrometer thin fibers. So far, MEW has mainly been applied for poly(ε-caprolactone). Here we manufactured scaffolds of poly(2-ethyl-2-oxazoline), a hydrophilic polymer with high melting temperature, by...
Hydrogen bond rich segmented poly(urethane-urea) was synthesized from methylene diphenylisocyanate (MDI) and three generations of polyurea-malonamide dendrons as hard segment and polycaprolactone diol as soft segment for thin film applications. The prepared polymers were characterized using spectroscopic, microscopic and thermal analyses. The formation of urethane linkage during the prepolymer reaction...
The structure of styrene-butadiene rubbers (SBRs) consists of chains attached to cross-links of relatively small number density. These rubbers show an α-relaxation process that is attributed to segmental motions of the attached chains. To investigate how an SBR's rubber-like behavior would change when free chains interpenetrate its structure, we prepared one SBR of mol wt 120 × 103 containing 3–4%...
Development of technologies for constructing three-dimensional (i.e. non-planar) transparent conductive electrodes from polymeric materials is a major goal in diverse applications, including optoelectronic devices, flexible electronics, photovoltaics, and others. We present a facile new strategy for creating conductive, transparent gold layering on polystyrene, a widely-used polymer, in different...
We develop approximate analytical (AA) model to describe the structure of a brush made of starlike polymers (regularly branched dendrons of the first generation) grafted by one arm onto a planar surface. It is demonstrated that introduction of two sub-layers with distinct populations of strongly and weakly stretched dendrons allows for adequate semi-analytical description of these end-grafted macromolecules...
Polymerisation of isoprene was performed by means of ternary catalytic systems made of Ln[N(SiMe3)2]3 (Ln = Nd (1), Y (2))/borate/Al(iBu)3 combinations (borate = [HNMe2Ph][B(C6F5)4] (HNB), [CPh3][B(C6F5)4] (TB) or B(C6F5)3 (Barf)). With borate activator B(C6F5)3, highly active (up to 4700 kg mol−1h−1) and selective catalysts are obtained with both neodymium and yttrium metals, leading up to 96% cis-1,4-polyisoprene.
Sol/Gel behavior of a mixture of two Pluronic species with non-identical polypropylene oxide (PPO) and polyethylene oxide (PEO) block lengths in aqueous medium is explored. Emphasis is placed on the nature of micelles (either mixed or separate micelles), nature of gelation, gel strength and microstructure. Two mixtures are considered: F127 + L64 and F127 + P105. Cooperative aggregation leading to...
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