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U članku su navedena tri problema koji se rješavaju modeliranjem linearnom funkcijom pomoću računala. Navedeni problemi se mogu razviti u nastavne scenarije, jer posjeduju otvorenost i istraživački potencijal u skladu s teorijom Realističnog matematičkog obrazovanja.

Two types of Japanese papers containing 100 % (JP1) and 50 % (JP2) kozo fibers were treated with different adhesives: methyl-cellulose, rice starch, hydroxypropyl-cellulose and acrylic copolymer. The Fourier transform infrared spectroscopic (FTIR) analysis confirmed the formation of adhesive layer on the surface of papers. The influence of accelerated ageing procedures of moist heat ageing and UV radiation on sample surfaces was established using FTIR and contact angle measurements. The degradation level of papers was studied measuring the intrinsic viscosity and determining the degree of polymerization. Mechanical properties were determined by tensile tests. The results showed that the polar and dispersive components of the surface energy depend strongly on the surface treatments as well as on conditions of ageing. Analysis of degree of polymerization and tensile strength revealed that treatment with methylcellulose, rice starch and hydroxypropyl- cellulose reduced degradation of Japanese papers.

Poly(ethylene terephthalate) nanocomposites reinforced with 1 wt% of nanodiamond terminated with carboxylic groups or nanodiamond and 0.3 wt% nanographene platelets were prepared by simple melt blending in a twin-screw extruder to create high-performance polymer nanocomposites for application in high radiation environments. A study of structural modifications introduced by high-energy, 3 MeV proton beam irradiation of poly(ethylene terephthalate) and its nanocomposites was conducted using attenuated total reflectance Fourier transform infrared and Raman spectroscopy, differential scanning calorimetry, and photoluminescence measurements. It was shown that the composite materials containing small concentrations of nanodiamonds or nanodiamonds plus nanographene platelets exhibit improved radiation resistance compared with neat poly(ethylene terephthalate) exposed to proton irradiation under the same irradiation conditions. The nanocomposites containing the combination of nanodiamonds and nanographene platelets exhibited the highest stability. Nanofillers, particularly nanographene platelets, stabilized the amorphous phase and increased the crystallinity of polymer matrix exposed to proton irradiation, preserving polymer conformation, molecular weight distribution, and overall thermal properties of irradiated nanocomposites.

Summary In this work 3-glycidoxypropyltrimethoxysilane polymer with inorganic SiOSi bonds was prepared by a sol-gel process. The structure of polymer was characterized by vibrational spectroscopy (Raman and IR). The interpretation of vibrational spectra is supported by the normal coordinate analysis based on density functional theory (DFT) calculations. A conformational and vibrational analysis of lowest energy dimer structure has been carried out by DFT calculations using Becke's three-parameter exchange functional in combination with the Lee-Young-Parr correlation functional (B3-LYP) and standard 6–311 + G(d,p) basis set. The comparison of theoretical spectra with the experimental data enabled us to extract the characteristic vibrational bands of polymer structure. The inorganic polymerization gives rise to siloxane network with SiOSi stretchings at 1030 and 1134 cm−1 suggesting the ladder-type structure of GPTMS polymer.

A series of poly(dimethylsiloxane)-zinc oxide (PDMS-ZnO) nanocomposites having different concentrations of ZnO nanoparticles (0, 1, 5, 10 and 20 wt%) have been prepared. Raman and FTIR-ATR spectroscopic analysis was performed in order to determine the interaction between the ZnO nanoparticles and PDMS polymer matrix. Density functional theory (DFT) using the (B3-LYP)/6-311++G(2df,2p) method was used to investigate the vibrational spectra of PDMS. A complete vibrational assignment is supported by the normal coordinate analysis, calculated Raman activities as well as IR intensities. The presence of ZnO nanoparticles in PDMS gives rise to significant differences in relative intensities of the characteristic vibrational bands with respect to the cross-linked polymer. The changes in relative intensities of Raman bands, as well as swelling measurements, were used to explain the effect of ZnO nanoparticles on the cross-linked structure of PDMS nanocomposites. It is established that ZnO nanoparticles influence the cross-linking density of the polymer matrix.

Two series of thin films of polyether-based polyurethane–silica nanocomposites having hard segment content of 51% and 34% and different concentrations of SiO2 nanoparticles (0, 0.5, 1.0 and 3.0 vol.%) have been prepared. Infrared linear dichroic (LDIR) ratio, mechanical and differential scanning calorimetry (DSC) measurements were performed in order to determine the influence of hydrogen bonding on their mechanical and thermal properties. The degree of phase separation (DPS) and orientational functions in dependence on strain were calculated from the polarized IR spectra. The presence of silica nanoparticles gives rise to significant differences in the mechanical (stress–strain) properties of the nanocomposites with regard to the pure polymer. The nanocomposite thin films with lower hard segment content (HSC) displayed decreased stiffness and tensile and increased elongation at break in comparison to the nanocomposites with higher HSC. There was no distinctive influence of nanoparticles on the glass transition temperatures of soft segments. Nanosilica significantly affected the melting behavior of the hard phase only in samples with higher HSC.

Molecular structure and vibrational frequencies of 3-glycidoxypropyltrimethoxysilane (GPTMS) have been investigated by density functional theory (DFT) calculations using Becke’s three-parameter exchange functional combined with Lee–Young–Parr correlation functional (B3-LYP) and standard basis set 6-311++G(d,p). In order to reveal some possible conformations of GPTMS, potential energy scan has been performed in three dihedral angles SiCCC, CCCO and OCCO. The calculations predict the existence of seven different conformations. Raman and IR spectra of liquid samples were recorded and complete assignment of the observed vibrational bands of GPTMS molecule has been proposed. Temperature dependence of Raman spectra between 203 K and 293 K was examined and vibrational modes characteristic for different conformers were detached.

The Raman spectra of aminopropylsiloxane (APS) polymerized on PVC substrate in DC electric field were measured to study the structure of deposited films. The modelling of low wavenumber Raman spectra was achieved using contribution of acoustic phonons, intramolecular vibrations as well as optical phonons related to librational motions of ladders. Results suggest that electric field influences on the orientations of ladders increasing thus the degree of order in microdomains.

Morphological, mechanical, and Fourier transform infrared dichroic investigations were performed on neat polyurethane (PU) polymer matrix and PU+CaCO3 nanocomposite thin films to determine how the nanofiller influenced the mechanical properties. The measurements were performed on strips that were cut from the prepared films in parallel and perpendicular directions with respect to the direction of film preparation. Optical microscopy of PU and the PU+CaCO3 nanocomposite revealed the strain-induced transition from a continuous spherulitic morphology to a fiberlike structure. The stress–strain behavior of the neat PU and PU+CaCO3 nanocomposite films showed significant differences at large strain regimes. The experimental results suggest that the mechanical properties were strongly related to the orientational behavior of the separated phases. The orientation of the hard and soft segments was analyzed by the orientation function calculated from the IR absorbances. A correlation between the orientations of segments, tensile properties, and hardness of the investigated polymer films was established. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

A comprehensive conformational and vibrational analysis has been carried out on gamma-aminopropyltriethoxysilane (APTES) by density functional theory (DFT) using Becke’s three-parameter exchange functional in combination with the Lee–Young–Parr correlation functional (B3LYP) and standard 6-31G(d, p) basis set. The scanning of the potential energy surface with respect to the SiCCC torsion angle suggests that there are five stable conformations. There are two minima with trans ( t 1 , t 2 ) conformations as well as three local minima corresponding to gauche ( g 1 , g 2 , g 3 ) conformations. The lowest energy conformer has trans-t 1 structure with SiCCC dihedral angle of 178.8°. The gauche conformers with torsion angle around 70° have various orientations of ethoxy chains. The calculated barriers to the conformation interchange are: 114, 484, 1272, 1239 and 1120 cm −1 for the trans-t 1 to trans-t 2 , trans-t 1 to gauche-g 1 , trans-t 1 to gauche-g 2 , trans-t 2 to gauche-g 2 and gauche-g 2 to gauche-g 3 conformers, respectively. The infrared (500–4000 cm −1 ) spectra and Raman (50–3500 cm −1 ) spectra of liquid APTES with qualitative polarization measurements have been recorded. A complete vibrational assignment for APTES conformers is supported by the normal coordinate analysis, calculated IR intensities as well as Raman activities. On the basis of the results, the vibrational spectra of APTES have been analyzed. The average error between the observed and calculated frequencies is 10 cm −1 .

Poly(ethylene terephthalate) (PET) nanocomposite film with 1wt% of nanodiamond terminated with carboxylic groups (PET- NDCOOH), PET nanocomposite film containing 1 wt% of NDCOOH and 0.3 wt % nanographene platelets (PET- NDCOOH-NGP) and a neat PET film have been prepared by melt extrusion. A Raman spectroscopic study was performed in order to establish the interactions between nanofiller (NDCOOH and NGP) and polymer matrix. The thermal behaviour of the PET nanocomposites was studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Mechanical properties were determined by tensile tests performed on strips that were cut from the prepared films in parallel and perpendicular directions with respect to the direction of film preparation. Raman and DSC results showed thar the incorporation of NDCOOH and NGP into the composite results in the enhancement of the crystallinity inducing the growth of crystalls in the polymer matrix. According to TGA results, the addition of NDCOOH and NGP enhanced thermal stability. The results obtained from the tensile strenght tests in the longitudinal direction showed that the incorporation of NDCOOH particles resulted in matrix plasticization. The increase in stiffness in the transversal direction can be ascribed to interactions between NDCOOH and PET matrix. The tensile strenght of PET-NDCOOH-NGP nanocomposite film in both directions decreased in comparison to neat PET.

Density functional theory, using the B3-LYP/6-31G(d, p) method have been used to investigate the conformation and vibrational spectra of aminopropylsilanetriol (APST) NH2CH2CH2CH2Si(OH)3. The potential function for CCCSi torsion gives rise to two distinct conformers trans and gauche. The predicted energy of the more stable trans conformer is 337 cm-1 less than the energy of gauche conformer. The calculated barriers to the conformation interchange are: 1094.5, 2845.0 and 437.8 cm-1 for the trans to gauche, gauche to gauche and gauche to trans conformers, respecively. For the trans conformer the potential energy curve for the Si(OH)3 groups torsion in APST has been calculated changing the HOSiC dihedral angle. The barrier for the internal rotation of 3064.6 cm-1 has been obtained. The optimized molecular structure of APST dimer calculated for trans conformer has a Si-O-Si angle of 143.24 , and a Si-OSi bond length of 0.164 nm. A complete vibrational assignment for both conformers as well as for trans-dimer is supported by the normal coordinate analysis, calculated IR intensities as well as Raman activities. On the basis of the results, the vibrational spectra of APST aqueous solution and APST polimer have been analyzed. The average error between the observed and calculated frequencies is 14 cm-1.

Low wavenumber polarized Raman spectra of aminopropylsilanetriol (APST) polymer deposited on PVC substrate were measured in the temperature range from 300 K to 78 K. In the low wavenumber Raman spectra of these samples a very strong Bose band was observed. The best results in modeling the low wavenumber Raman spectra were achieved with the exponential correlation function of disorder Gdis(ν) = exp (−r/Rc)using three contributions: transversal and longitudinal acoustic phonons and molecular vibration. Results suggest medium range ordered ladder structure, stacked in layers with different orientations of ladders.

Low-frequency Raman scattering was used to study amorphous solid films of adamantane, a globular non-polar hydrocarbon molecule. As evidenced by its spectral characteristics this type of disorder is different from the orientational disorder found in the room temperature plastic phase by the absence of the translational order as well. This gives rise to the boson peak related to acoustic phonons which gradually disappears upon heating with simultaneous emerging of the phonon line at 50 cm−1 which characterizes the low-temperature ordered phase of adamantane. Adamantane dynamics resembles that of C60 fullerene although not in the same temperature range. All this makes adamantane an attractive system that could serve as a practical reference in molecular simulation studies of the glassy phase of model fluids.

The paper presents yet another elegant solution to the classical problem of maximizing the range of a projectile fired from above or from below the horizontal target plane. The method makes use of the envelope of the family of the projectile trajectories and it not only solves the original problem, but can be applied to maximize the projectile range on a target surface of arbitrary shape. Three different ways of deriving the equation of the envelope are shown. As an example the range of a projectile is maximized on a parabolic target surface. The envelope can also be used to minimize the kinetic energy of a projectile given the target point.

The low-wavenumber (10–200 cm−1) polarized Raman spectra of 4,4′-dibromobenzophenone single crystal at different temperatures (10–295 K) and far-infrared spectra (20–200 cm−1) of powdered samples at room temperature were recorded. The assignment of the lattice vibrations based on the lattice dynamics calculation at k = 0, which takes into account the seven lowest intramolecular modes, is presented. The unusual temperature behavior of some bands was explained by dephasing relaxation processes. Copyright © 2002 John Wiley & Sons, Ltd.

Infrared and Raman spectra of crystalline, melted and solvated ortho-terphenyl and its perdeuterated isotopomer, D_14-ortho-terphenyl, have been recorded. Optimized geometries and vibrational frequencies were calculated by the semiempirical RHF/AM1 method and by means of DFT method using B3LYP functional and 6-31G(d) basis set. In both cases the lowest energy conformation is of C_2 symmetry. With the scaled AM1 and B3LYP/6-31G(d) force fields the average error in reproducing the experimental molecular vibrational frequencies is 13 and 5 cm^-1, respectively. The AM1 potential energy surface for phenyl torsions was mapped on a 15 deg grid. The barrier to concerted internal rotation is estimated to lye between 3 and 6 kJmol^-1. The calculations of the lattice dynamics at k=0 in the low-temperature fully ordered crystal phase of parent and deuterated ortho-terphenyl were performed with inclusion of six low-lying intramolecular vibrations. The conformational change of the ortho-terphenyl molecule induced by crystal packing forces was taken into account by redefining the unperturbed molecular vibrational states. Although an accurate assignment of lattice vibrations was not possible, the calculated spectra give quite reasonable picture of the low-frequency dynamics in crystalline ortho-terphenyl. The relevance of the obtained results to the glass forming property of ortho-terphenyl is discussed.

Raman (3100–10 cm −1 ) and IR (3100–200 cm −1 ) spectra of solid and dissolved 1,1′-biadamantane were recorded. The molecular structure and vibrational normal modes were calculated using the semi-empirical AM1 Hamiltonian. The distortions from the tetrahedral geometry induced by linking two adamantane units are discussed. The potential barrier of 19.3 kJ mol −1 for internal rotation of two adamantyl cages around the central bond was determined by calculations of heat of formation for fully relaxed structures at different dihedral angles. The final scaled vibrational force field was obtained by transferring the scale factors from parent adamantane. The normal mode displacements are described in terms of adamantane normal mode displacements using the generalised harmonic mode scrambling approach. The central bond stretching, torsion around the central bond and CCC deformations involving the central bond are genuine 1,1′-biadamantane vibrations. The semi-rigid molecular model is qualitatively applied on lattice dynamics of 1,1′-biadamantane in order to assign two Raman bands observed below 100 cm −1 .

A cage-like polar molecules of 2-adamantanone (C10H14O) at room temperature form plastic crystal phase. We present the experimental results that show the existence of different low-temperature structures of 2-adamantanone: glassy crystal state, ordered crystal state and amorphous state in the form of molecular films. The glassy crystal state is obtained by rapid undercooling of a plastic phase. The freezing primary involves the rotational degrees of freedom of molecules but the translational order of the plastic phase is preserved. The phase transition to the ordered crystal state is observed after a very slow annealing process between the room temperature and 10K. Amorphous 2-adamantanone films were prepared by vacuum evaporation and deposition onto cold metal substrate at temperature 10K. The different low-temperature structures of 2-adamantanone have been studied by Raman spectroscopy. The low-frequency Raman spectra are analysed by means of reduced Raman intensity . The reduced intensity of light scattering in disordered materials is given by: where is Bose factor, describes the coupling between light and vibration modes, is the density of states. The analysis of reduced Raman intensity shows that the structures of different low-temperature 2-adamantanone states are reflected in the characteristic low-frequency spectra.

The vibrational analysis of 2-adamantanone and the group of all possible mono- and two gem-dideuterated 2-adamantanone isotopomers (2-adamantanone-3-d1, 2-adamantanone-endo-4-d1, 2-adamantanone-exo-4-d1, 2-adamantanone-5-d1, 2-adamantanone-6-d1, 2-adamantanone-4,4-d2 and 2-adamantanone-6,6-d2) is presented. The assignments for fundamentals are based on the characteristic group frequencies, i.e. comparison with adamantane, Raman depolarization ratios, isotopic frequency shifts and are supported by the normal coordinate calculations. The force field was obtained from the semiempirical AM1 calculations and the assumed transferability of the scaling factors for adamantane. The average error between the observed and calculated frequencies is 11 cm−1. The effects of the carbonyl group and deuterium substitutions on the adamantane-like normal modes were investigated in terms of the harmonic mode scrambling analysis.

The properties of the propellane bond in 2, 4- methano-2, 4-didehydroadamantane (1) and 2, 4- (dimethylmethano)-2, 4-didehydroadamantane (2) have been determined on the basis of the spectroscopic and chemical evidence. A monitoring of reaction of propellane 2 with dimethyl disulfide by Raman spectroscopy has indicated the cleavage of the central bond between inverted carbon atoms. Raman and infrared spectra of 1 and 2 as well as bf their dihydro congeners 2, 4-methanoadamantane (3) and 2, 4-(dimethylmethano)adamantane (4) have been recorded. To describe the vibrational and molecular orbital properties of these compounds (harmonic frequencies, heats of formations, bond orders, and charge distributions), AM1 semiempirical calculations were performed. The calculated properties are found to be in fair agreement with the observed ones. By combining the results of spectroscopic investigations and molecular orbital calculations, the central bond between inverted carbon atoms is associated with the highest occupied molecular orbitals in propellanes 1 and 2. Assuming the transferability of the adamantane scaling factors for force constants within the studied group of molecules, an ""a priori"" assignment of the observed bands has been obtained.

Raman spectrum of aminopropylsilanetriol (APST) in gas phase has been recorded at room temperature in macro chamber utilizing two-mirror technique over the sample tube. Unlike predominantly trans molecular conformation in condensed phase, the spectra of vapor show that the molecules are solely in gauche conformation with intramolecular hydrogen bond N···HO which reduces the molecular energy in respect to trans conformation by 0.152 eV. The assignment of the molecular spectra based on the DFT calculation is presented. The strong vibrational bands at 354 cm(-1), 588 cm(-1) and 3022 cm(-1) are proposed for verifying the existence of the ring like, hydrogen bonded structure. Special attention was devoted to the high frequency region, where hydrogen bond vibrations are coupled to stretchings of amino and silanol groups.

Summary In this study poly(dimethylsiloxane) (PDMS) nanocomposites with 1wt % of zinc oxide (ZnO) and 1wt % of silanized ZnO nanoparticles were prepared through cross-linking reaction. The prepared samples were irradiated under vacuum at room temperature with a 2 MeV proton beam with fluences in the 1013–1015 cm−2 range. The influence of nanoparticles on the cross-linking processes and structural degradation of irradiated PDMS nanocomposites was investigated using Raman and Fourier transform infrared spectroscopy (ATR). The analysis of vibrational spectra has shown that prepared PDMS nanocomposites have higher resistance to proton irradiation in comparison to pristine PDMS. Under the highest proton irradiation fluence (1015 cm−2) PDMS with 1 % ZnO provided the best radiation protection.

Raman and infrared spectra of adamantane-d0 and several of its isotopomers (adamantane-1-d1, adamantane-2-d1, and adamantane-2,2-d2) have been recorded and assigned using the valence empirical force field and isotopic frequency shifts. Few inactive fundamentals of adamantane-d0 were located by means of their activity in either the low-symmetry isotopomers or the low-temperature phase. The vibrational spectrum of adamantane-d16 had to be reinterpreted. The force field obtained from the semiempirical AM1 parametrization was scaled using the vibrational assignments for adamantane-d0, -d16 and -1-d1. The two force fields were compared. Both reproduced the observed frequencies with practically the same average error of 16 cm−1. However, the number of parameters in the scaled semiempirical force field is only nine compared with 27 of the empirical force field.

In this work we investigated the solidification of aminopropylsilanetriol dissolved in water (∼25%) under different conditions by Raman spectroscopy. The solidification was carried out at three different temperatures 8 °C, 23 °C and 60 °C. The influence of electromagnetic radiation on the polymerization process was also studied. Samples were held to solidify in dark and at UV (254 nm and 356nm) spectral range. In order to investigate the influence of the substrate on the resulting polymer structure, teflon, PVC, glass, brass and silica were used. Best ordered polymerized structure was achieved for samples deposited on plastics and solidified in dark, at room temperature.

Thin films of polyester-based polyurethane-silica nanocomposites with 34% hard segments and different concentrations of nano SiO2 filler (0, 0.5, 1.0 and 3 vol.%) have been prepared. The hydrogen bonding and orientational behaviour of hard and soft segments were analysed using infrared linear dichroic measurements. The number of hydrogen bonded NH and C=O groups and orientation function were calculated from polarized FTIR spectra. The presence of nanosilica slightly increased the number of hydrogen bonded carbonyls. The soft segments in nanocomposite films display increased orientation in comparison to the neat polymer film. The addition of 3% nanosilica significantly reduced elongation at break. The results were compared with hydrogen bonding and orientational behaviour of thin film of polyether-based silica nanocomposites.

In this work, we investigated IR and Raman spectra from 400–1800 cm −1 of aminopropylsiloxane (APS) polymerized on PVC substrate at room temperature. Complete assignment of the vibrational spectra was carried out using density functional theory calculations with Becke’s three-parameter exchange functional in combination with the Lee–Young–Parr correlation functional (B3-LYP) and standard 6-311++ G(d, p) basis set. The vibrational spectra were calculated for two different conformations of silicooxygen rings: ladder structure and cubic structure. Comparative analysis of calculated and measured spectra reveals that ladder structure has been formed at the surface of PVC support.

In the present study, three different nanocomposites of poly(dimethylsiloxane) (PDMS) with 1 wt.% of nanoparticles (NP) of detonation nanodiamond (DND) (PDMS-DNDS), zinc oxide (ZnO) (PDMS-ZnO), and single-walled carbon nanotubes (SWNT) (PDMS-SWNT) were irradiated under vacuum at room temperature with a 2 MeV proton beam with fluences in the 1013 to 1015 cm-2 range. Modification of the structures and properties of the nanocomposite materials were monitored as a function of proton fluence. Specifically, the vibrational dynamics of PDMS-nanocomposites for unirradiated and irradiated samples, were investigated using Raman and Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR-ATR) and compared. The results were also compared with the results obtained for the unirradiated/irradiated pure PDMS polymer. The Raman and FTIR-ATR spectra of the PDMS nanocomposites exhibit an overall reduction in intensity of the characteristic vibrational bands of the irradiated samples. However, an important difference between the irradiated pure PDMS versus PDMS nanocomposites’ Raman and FTIR spectra appeared ; comparable structural degradation of polymer nanocomposites with ZnO, DND and SWNT fillers takes place at least at one or even two orders of magnitude higher fluence than for pure PDMS, indicating the potential use of ZnO-based, DND-based and SWNT-based polymer composites in high radiation environments. The highest resistance to radiation was demonstrated for PDMS-ZnO samples. Since the benefit is realized at a low loading, the cost of the nanocomposite can be kept low and the polymer retains the other beneficial properties that make them attractive.

In the present study, pure poly(dimethylsiloxane) (PDMS) polymer and PDMS-detonation nanodiamond (PDMS-DND) composite with 1wt.% of DND were irradiated under vacuum at room temperature with a 2 MeV proton beam with fluences in the 1013 to 1015 cm-2 range. Modification of the structures and properties of the pure polymer and the nanocomposite material were monitored as a function of proton fluence. Specifically, the vibrational dynamics of pure PDMS and PDMS-DND nanocomposites, both unirradiated and irradiated samples, were investigated using Raman and Fourier transform infrared spectroscopy (FTIR). The Raman and FTIR spectra of the PDMS and PDMS-DND composites exhibit an overall reduction in intensity of all vibrational bands of the irradiated samples. The changes in relative intensities of the characteristic vibrational bands as a function of irradiation fluence indicate that cleavage of the backbone (Si-O-Si) PDMS chains was most pronounced. Importantly, structural degradation of PDMS-DND composites takes place at an order of magnitude higher fluence than for pure PDMS, indicating the potential of using DND-based polymer composites for application in high radiation environments. The appearance of strong photoluminescence (PL) following irradiation was more pronounced for PDMS-DND composites as compared to pure PDMS.

The versatility of pressure-sensitive adhesive tapes (PAT)s is achieved by using various components to obtain the most important property of PAT – having the adhesive on (usually) a single side of the carrier. Most common carriers are OPP, PVC, PE, paper, etc. Primer coating is usually applied to connect the adhesive to the carrier although there are PATs without primer. Various compositions of the main adhesive can be divided in two main groups: solvent-based and hot melt. The adhesives can also be divided according to the elastomer used what is more important from the chemical point of view. The adhesivity depends on the (combination of) resins used and is adjusted according to the type of the carrier and the application of PAT. The non-adhesive side of the carrier may be coated with release coating to ease unwinding of the tape nd/or printed after applying the coating. The pigments may be added to the adhesive and/or the carrier. Even from such simplified description it is obvious that the PATs are very complex systems that have not been much studied so it is quite a challenge to approach any of the problems that might be encountered in course of their production. A part of investigations performed during more than a decade long cooperation with Sipro d.d., Umag in solving some of their production problems is presented. In number of occasions various spectroscopic techniques were used to analyse PATs with solvent-based adhesives and their components to determine the cause of problems encountered in production. Differences in abietic acid based resins were observed in FTIR spectra resulting in selection of more appropriate one. Similar resin that is a component of titan-dioxide based white pigment reduced cohesion of the adhesive to which it was added resulting in contamination of nonadhesive side of the tape what caused problems on printing onto the tape. NMR analysis of the main adhesive were performed on dissolution with an appropriate solvent and a correlation of noisy unwinding and the ratio of elastomer to reisns were determined. These experiments confirmed the role of spectroscopy in resoving problems in production of PATs and its importance in quality assessment. The need of further improvement in the use of those methods for research on polymer based adhesives became more obivous.

Poly(ethylene oxide), PEO, is a versatile semicrystalline polymer. The reduction of the degree of crystallinity is preferred for some applications and can be achieved by irradiation in appropriate conditions. This presentation is a part of the study on the outcome of interactions of various factors on irradiation effects in PEO and its nanocomposites. If irradiated dry, the PEO chains are directly affected so in presence of oxygen PEO generally degrades, while the changes observed on irradiation in the inert atmosphere are consistent with partial crosslinking. In aqueous solution radiation produces reactive species in water and the reaction of these species with PEO chains is supposed to lead to crosslinking. We prepared aqueous solutions of PEO with nano-silica and without it. The solutions were irradiated by γ-radiation to various doses at different dose rates. The dried samples were investigated by differential scanning calorimetry (DSC), FTIR spectroscopy and X-ray diffraction (WAXD). The DSC peaks broadened and shifted to significantly lower temperatures compared to unirradiated PEO. The diffractograms display either small maxima (no shifts that would indicate the structural changes were observed) or are fully amorphous at higher doses. The greatest changes in FTIR spectra were observed in the shape and the absorption intensities of –C–O–C– triplet at around 1100 cm-1. The vibrations characteristic of crystalline PEO at 1342 cm-1 and 1360 cm-1 merged into a single absorption that is typical for melt and indicates amorphization. The significant decrease in crystallinity appeared at much lower doses that would cause degradation. Those results suggest crosslinking of PEO irradiated in aqueous solution occurred but specific spectral changes have yet to be found. The concentration of aqueous solution was significant for the outcome while radiation dose rate and the molecular mass of PEO had minor influence. The nano-silica contributed to the effects of irradiation implying synergism.