A new route for atom-economical synthesis of functional polymers was developed. Oxidative polycoupling of 3,5-dimethyl-1-phenylpyrazole with 4,4’-(α,ω-alkylenedioxy) bis(diphenylacetylene)s and 1,2-diphenyl-1,2-bis[4-(phenylethynyl)phenyl]ethene, respectively, were catalyzed by [Cp*RhCl2]2, 1,2,3,4-tetraphenylcyclopenta-1,3-diene and copper(II) acetate in dimethylformamide under stoichiometric imbalance conditions, affording soluble poly(pyrazolylnaphthalene)s in satisfactory yields (isolation yield up to 82%) with high molecular weights (Mw up to 35700). All the polymers were thermally stable, losing little of their weight at high temperatures of 323–422 oC. They possessed good film-forming property and their thin solid films showed high refractive indices (RI = 1.747–1.593) in a wide wavelength region of 400−1000 nm. The polymer carrying tetraphenylethene unit displayed a phenomenon of aggregation-induced emission and showed enhanced light emission in the aggregated state.

The metal-catalyzed step-growth radical polymerization was achieved to enable two systems for preparing tailored polymeric structures, i.e., sequence-regulated vinyl copolymer and periodically-functionalized polymer. The former is a novel strategy for preparing sequence-regulated vinyl copolymers by step-polymerization of sequence-regulated vinyl oligomers prepared from common vinyl monomers as building blocks. The later deals the simultaneous chain- and step-growth radical polymerization, which resulted in the polymers with periodic functional groups.

A novel method was developed for the preparation of arborescent (dendritic graft) polymers, by successive grafting reactions of linear chain segments using alkyne-azide “click” chemistry coupling. A linear polystyrene substrate was thus randomly functionalized with acetylene functionalities, by acetylation and further reaction with propargyl bromide in the presence of potassium hydroxide and 18-crown-6 in toluene. The anionic polymerization of styrene was achieved with 6-tert-butyldimethylsiloxy-hexyllithium to obtain polystyrene with a protected hydroxyl chain end. Deprotection of the hydroxyl group, followed by conversion into tosyl and azide functionalities yielded the material serving as side chains in the grafting reactions. Coupling of the azide-terminated side chains with the acetylene-functionalized substrate in the presence of a Cu(I) catalyst proceeded in up to 93% yield. Additional cycles of substrate functionalization and side chain coupling led to arborescent polymers of generations G1 and G2, with low polydispersity indices (Mw/Mn≈ 1.1), in 60-84% yield. These polymers are characterized by a very compact structure, and molecular weights increasing geometrically over successive generations. A similar methodology was also shown to work for the synthesis of arborescent polybutadiene systems, using azide-functionalized substrates and alkyne-terminated side chains. The coupling reaction proceeded in up to 76% yield under optimized conditions for these systems.

Novel hyperbranched molecules containing pyrrole units were obtained from ortho-, meta- and para-diaminodiphenyldiacetylenes, as AB2 type monomers by one-step polymerization. Diacetylenic fragments reacted with terminal amino groups in the presence of copper chloride to give pyrrole units. Diaminodiphenyldiacetylene monomers have been synthesized from ethynilanilines in three steps. The novel monomers and hyperbranched molecules were characterized by NMR, IR and thermal analysis. Some conductivity proofs were also carried out and this behavior was assessed.

The electronic behavior of some of these molecules was studied by means of theoretical methods. DFT optimization processes were carried out for three structures derived from the generation growing. There are at least two conformational isomers of the structure (meta- and para-) which show conductivity properties, the meta-isomer shows semiconductor nature but this species is hard to modeling because the steric hindrances cause optimization problems and indeed the third generation species was not achieved. In other context, the para-isomer allows the calculation of three generations and shows clearly a tendency to narrow the energy gap between the frontier orbitals but besides the behavior of the HOMO-1 seems reinforce the conductivity phenomenon.

As a preliminary study aiming to possible applications, novel polythiophenes (PTs) derivatives of 3-hexylthiophene and a thiophene functionalized with pyrene chromophore were synthesized. Homopolymer and copolymers of these monomers were obtained in different stoichiometric ratios which allow obtaining structure-property relation of each of the polymers. PTs were characterized by FT-IR, 1H NMR, UV-vis, DSC-TGA, GPC and fluorescence experiments. Polymers have λmax between 345 to 450 nm and an emission band at 485 and 542 nm. Low molecular weights distribution (Mn = 875 to 1600 g/mol) and thermostable products (Td = 336 to 474°C) were obtained. These PTs functionalized with aromatic molecules and π-conjugated systems could offer interesting applications such as optical sensors, nonlinear optics and photovoltaic cells.

It has been found that the hybrid materials are a compatible matrix for numerous organic compounds, such as organic dyes, laser dyes, and compounds that exhibit photo-chromic behavior and many more The epoxy-silica system seems to be an excellent matrix for organic dyes and a hybrid material suitable for to be used as coating on glass substrates with good adhesion properties. This work presents a systematic study of the effects of the different amount of using rhodamine 6G as dye on the structure and properties of epoxy–silica hybrids coatings synthesized by the sol-gel process. We have taken advantage on the high solubility of organic dyes in a hybrid organic–inorganic epoxy resin–silica (epoxy–SiO2) matrix to obtain homogeneous, hard and high optical quality red color films on glass substrates. The effects of the content of rhodamine 6 G on the optical and thermal properties of epoxy-silica hybrid films were also examined. Epoxy resin DER 332 cured with an amine (4,4 diamino diphenyl methane) was used as organic component and tetraethyl orthosilicate (TEOS) was used as precursor of the inorganic component. The results showed that at a concentration of rhodamine 0.05% coatings retain adhesion properties similar to coatings without colorant and the coatings are uniform and free of defects. These coatings have the potential to be used as filters and ornamental coatings.

This work focuses on the effect of gamma-ray radiation conditions on the stimuli-responsive of polypropylene (PP) films and silicone (SR) rubber substrates grafted with N-vinylcaprolactam (NVCL) and acrylic acid (AAc). PP films and SR rubber were weighed and placed into glass ampoules and exposed to 60Co γ-source in the presence of air at room temperature, at dose rate around 12 kGy h-1 and dose between 5 and 70 kGy. Solutions of NVCL and AAc (1/1, v/v), 50 % monomer concentration (v/v) in toluene were added to the samples, the ampoules were degassed by repeated freeze-thaw cycles (5 times per 20 min) and sealed. The ampoules were heated at 60 or 70 °C at reaction time per 12 h. To extract the residual monomer and homopolymer formed during the grafting, the samples were soaked in ethanol for 24 h and then in distilled water, followed by drying under vacuum to constant weight. The values of grafting percentage achieved at a given irradiation dose were higher for SR than for PP. Samples where characterized by FTIR-ATR, DSC, swelling, LCST, and pH critical point.

Here we report the preparation of functionalized latexes with isocyanate groups through an emulsion terpolymerization of BA/St/TMI. The emulsions were stabilized with two surfactants, EF-800 or MA-80; the TMI acted as a self crosslinked promoter during the film formation. We found a strong dependence of surfactant type in particle size and particle number. Moreover colloidal stability of latexes by a period of time was different, and the best colloidal stability was obtained with EF-800 surfactant. Swell index and mechanical properties of latex films were studied.

In this work, the synthesis of two amphiphilic π-conjugated compounds such as ferrocenylthioamide and ferrocenylselenoamide, with the general formula FcC=MNH(CH2)15CH3 with M = S or Se, are reported. The ferrocenyl group is a donor moiety forming a π-conjugated system with the amides of sulfur and selenium; both elements have also bioactivity with pharmacological interest. These two compounds formed Langmuir (L) monolayers at the air-water interface, which were characterized by isotherms of surface pressure versus molecular area (π-A) and compression/expansion cycles (hysteresis curves); Brewster angle microscopic images were also obtained. By using the Langmuir-Blodgett method molecular monolayers were transferred onto glass substrates. These nanostructures, in form of Langmuir-Blodgett (LB) films, were characterized through atomic force microscopy (AFM).

Agave fibers were used to elaborate a transparent and flexible cellulose hydrogel films used as scaffold for tissue regeneration and tested by in vitro assays with NIH 3T3 fibroblast cells. Using dimethylacetamide/lithium chloride (DMAc/LiCl) system was possible to obtain cellulose solutions and hydrogel films were prepared by phase inverse method without cross-linker. The concentration of LiCl in the DMAc solution was varied from 4 to 12 wt% in the phase inversion process and then the cytotoxicity was tested for 14 days on the cultivation. The resultant hydrogel films showed better cytocompatibility than the PS dish used as control. The cell growing images showed that the hydrogel films with lower LiCl apparently contained ordered and aggregated fiber orientation. This comparison suggested that the segmental microstructure in the hydrogel films influenced fibroblast cells spreading. In addition, the agave hydrogel films displayed good stability without biodegradiation through the cell cultivation.

The molecular relaxations behavior of chitosan (CS) films in the wide frequency range of 0.1-3x109 Hz (by using three different impedance analyzers) have been investigated in the temperature range of -100C to 120°C using Dielectric Spectroscopy (DS). Additionally to the low frequency molecular relaxations such as α and β relaxations, for the first time, high frequency (1-3 GHz) relaxation process has been observed in the chitosan films. This relaxation exhibits Arrhenius-type dependence in the temperature range of -100 C to 54°C with negative activation energy -2.7 kJ/mol. At temperatures above 54°C, the activation energy changes from -2.7 kJ/mol to +4.4 kJ/mol. Upon cooling, the activation energy becomes negative again with a value of -1.2 kJ/mol. The bound water between chitosan molecules strongly modifies molecular motion and the relaxation spectrum, giving rise to a new relaxation at the frequency at ca. 1 GHz. In situ FTIR analysis has shown that this relaxation related to the changes in vibration of the –OH, NH and –CO functional groups.

This study aimed to evaluate the effect of 12 substrates in the seedling growth of chili apple (Capsicum pubescens R. & P.) hybrid Grajales ST. The substrates were prepared with different proportions of five materials: perlite, coconut fiber, loam, Sunshine3 ® and wood dust. The seeds were sown in trays of 50 cavities. For the substrates were determined physical and chemical properties. Significant differences in growth parameters of seedlings are the effect of the substrate. Based on the remarkable accumulation of dry matter of each of the organs of the seedling, and their relative distribution, one can surmise a seedling quality with 47.70 % dry matter in leaves, 35.34 % in stem and 16.95 % in root. The substrate with better features for the production of chile apple seedlings was prepared with 25 % loam and 75 % perlite (v/v), which showed retention of 85.5 % moisture, electrical conductivity of 0.03 dS·m-1 and total porosity of 62.5 %.

This study demonstrates the potential application of glass particles doped with Zn+2 (GZn) as antimicrobial additives and atoxic of the HDPE and LLDPE polymers. Toxicity tests indicated the absence of toxicity in human cells. Microbiological tests proved the antimicrobial effect of GZn pure compound and of the additives polymeric compounds (HDPE/GZn and LLDPE/GZn). Have also indicated that with percentages of GZn higher than 2.00 wt% and a time of 4 hours the bactericidal performance is excellent and equal for both polymeric compounds.

The kinetic performance of metallocene type catalysts as well as their instantaneous activity is determined on line by two independent methods in the semi-batch polymerization of ethylene via metallocenes. On the basis of first-principles, both methods are described and guidelines for their implementation at a laboratory scale reactor are offered. Polymerization tests were conducted with two heterogenized metallocene catalysts showing that the direct method (based on ethylene flow measurement) and also the calorimetric method (based on energy balances) reported equivalent high quality information. The calorimetric method here developed can be readily used by the chemical practitioner as the notions and tools required for its implantation are easily grasped. It is noted that the calorimetric method has the advantage of requiring a low cost instrumentation (only thermocouples) whereas the direct method needs a relatively more sophisticated equipment (mass flow meter).

Sol-gel coatings show an excellent chemical stability, oxidation control and enhanced corrosion resistance for metal substrates. An organic-inorganic hybrid consisting of poly (methyl methacrylate) (PMMA) and silica (SiO2) was successfully synthesized in the form of solution, by using 3-(trimethoxysilyl) propyl methacrylate (TMSPM) as a coupling agent and cohydrolyzed with tetraethyl orthosilicate (TEOS) to afford chemical bondings to the forming silica networks by a sol-gel method. The as-synthesized hybrid material was subsequently characterized by Fourier Transformation infrared (FTIR) spectroscopy. PMMA-SiO2 was applied as a protective film on hardness steel substrates by dip-coating. The thickness of the coating was 25 µm, while the roughness Ra = 0.6 µm. The wear and friction behavior of the coating on hardened steel (HS) was evaluated by a ball-on-disk test in dry conditions with a AISI steel ball as counterface applying 2, 4, 6, 8 and 10 N normal loads. Friction coefficient values (µk) were in the range of 0.76 to 0.99, whereas the lowest wear rate (k) was observed at 6N with a value of 1.30x10-4 (mm3(Nm)-1).

The effect of carbon nanotubes (CNTs) on the thermal and chemical stability of polypropylene (PP) when subjected to oxidation in a fuming nitric was evaluated. The effect of CNTs on the crystalline morphology and melting and crystallization temperature of PP was studied. The results shown a thermal stability increased markedly; the decomposition temperature, increased from 293°C for pure PP to 320°C for PP with CNTs. The crystallization temperature increased perceptibly in presence of CNTs. The oxidative degradation with nitric acid produced a reduction in molecular weight; however, this negative effect was less pronounced in the PP compositions with carbon nanoparticles. The morphological changes evaluated with X-ray diffraction showed that the alpha type crystallinity remains, irrespective of the nucleating agent, and the intensity ratios between reflections peaks was taken as an indication of an increasing nucleating efficiency.

We develop a program (within MATLAB software environment) to numerically simulate current-voltage characteristics of a bilayer organic light-emitting diode (OLED). The program is based on the Poole-Frenkel and Schottky continuous quantum models which take into account the geometry of thin films and their emission parameters in the calculation of charge carrier and current density in organic materials. Simulations are performed for OLEDs with A/EML/C and A/HIL/EML/C architectures where A=anode, HIL=hole injection layer, EML=emissive layer and C=cathode. For EML we assume MEH-PPV and MDMO-PPV derivatives of poly-para-phenylene-vinylene (PPV) polymer semiconductor, and for HIL we use PEDOT:PSS. The results of simulation are compared with experimental results obtained from actual OLED devices constructed in our laboratory. For comparison we also use the commercial software SimOLED to simulate the devices under similar architectures. We find in general a fair agreement between the simulated and measured behavior except for a few orders of magnitude difference in the current.

The thermoluminiscent properties of MEH-PPV and MDMO-PPV conjugated polymers were studied in order to verify if they are suitable for use as TL dosimeter. The dose response that was analyzed cover the wide dose range 0.34-5.44 kGy. The measured glow curves show complex structures which were evaluated with kinetic parameters based on the MO (Mix Order) model together with the CGCD (Computerized Glow Curve Deconvolution) homemade program which is useful to understand the mechanisms responsible for TL emission.

This study deals with evaluation of mechanical properties (tensile, flexural and impact strength), that verified reinforcing potential of nanofibres in polymeric composites and their applicability in dependence on the filler content of nanofibres of natural and synthetic origin. Considering the hydrophilic nature of natural nanofibres and hydrophobic polypropylene matrix was applied chemical modification that ensures effective interlock of nanofibres with the matrix, namely maleic anhydride grafted polypropylene and ionic modifier. Polymeric nanocomposites were prepared by twin screw extrusion that made possible mixing of all three components together. After cooling in water bath the composites were cut on pellets and dried for further injection moulding. The specimens were made of two- or three-phase component systems that included PP matrix, coupling agent in the volume of 4 wt.% and reinforcing nanofillers in the volume of 2, 4 and 6 wt.%. The presence of nanoparticles and coupling agents had not unambiguous impact on analysed mechanical properties. Coupling agent presence was dominant for impact strength, however, flexural and tensile properties were influenced mainly by the nanofiller type and origin. The dispersed phase and compatibilizer improved flexural modulus but tensile modulus of pure PP were not achieved by three-phase composite, not even with the highest analysed nanoparticle load. Cellulose fibres proved as more proper than the synthetic ones not only for their biodegradability and renewability but for their better toughness as well.

A multi-block associative polyelectrolyte based on poly(methacrylic acid-ra-styrene) [MAA-S] and poly(octadecyl methacrylate) [ODMA] was synthesized through stepwise nitroxide-mediated solution polymerizations. The obtained polymer has a heptablock copolymer structure, alternating MAA-S as hydrophilic blocks (theoretical degree of polymerization [DPT] of 250), and ODMA as hydrophobic blocks (DPT = 15). Rheological properties, in the linear-response regime, of aqueous solutions (polymer content = 1.5 wt.%) were studied as a function of the amount of blocks on the polymer using steady-shear and creep-compliance experiments. Rheological experiments demonstrate that the viscoelastic behavior of the polymer bearing an ODMA block in terminal position greatly differs from that of the polymer with MAA-S block terminations. The former behaves as a newtonian fluid on a wider range of shear rates than the latter, which exhibit a shear-thinning behavior, even at low shear rates, independently of the molecular weight and number of blocks.