bluuebunny/crossref_metadata_2025 huggingface dataset:
Zum einfluß von oligomeren auf die eigenschaften von styrol‐acrylnitril‐copolymerisaten
Authors: Schellenberg Jürgen , Hamann Bernd
Published: April 2003

Oligomere des Styrols und Acrylnitrils wurden isoliert und charakterisiert sowie ihr EinfluB auf die Eigenschaften von Styrol‐Acrylnitril‐Copolymerisaten bis zu einem Anteil von ca. 5 Gew.% im Polymerisat untersucht.

Hinsichtlich der mechanischen Eigenschaften wurden Biegespannung und Zugfestigkeit mit steigendem Oligomergehalt erniedrigt, während die Schlagbiegefestigkeit verbessert wurde. Die thermischen Eigenschaften wurden besonders hinsichtlich Glasübergangstemperatur und Vicat‐Erweichungstemperatur durch den Oligomergehalt stark beeinflußt. Rheologische Eigenschaften wurden durch Schmelzindex und Schmelzviskosität bei verschiedenen Schergeschwindigkeiten charakterisiert.

Der Einfluß der Verarbeitungsbedingungen auf die optischen Eigenschaften, die Lichtdurchlässigkeit und den Gelbindex werden beschrieben.
Alkylation of poly(n‐vinylpyrrolidone‐co‐vinylamine) with esters of phosphorous acids
Authors: Trendafilova‐Gercheva D. , Vassileva V. , Georgieva M. , Troev K. , Panarin E. F.
Published: April 2003

Alkylation of amino groups bounded to a polymer chain with esters of phosphorous acids was studied in order to obtain physiologically active polymers. Poly(N‐vinyl‐pyrrolidone‐co‐vinylamine) was chosen as a polymer‐carrier. The phosphorous acid esters used were dimethyl hydrogen phosphonate, dimethyl methanephosphonate, trimethyl phosphate and bis‐(2‐chloroethyl)‐hydrogen phosphonate. The composition and structure of the isolated final products was proved by IR‐ and NMR‐spectroscopy and elemental analysis. It is established that alkylation takes place to various extents.

The obtained alkylated phosphorous‐containing polymers exhibit herbicidal activity and could find application as plant growth retardants.
Reactions of iridium on a chelating sorbent involving N‐nucleophilic centres
Authors: Kálalová E. , Thuy P.
Published: April 2003

The chemical behaviour of the [IrCI6]2− choloro complex on a poly(glycidyl methacrylate) sorbent with ethylenediamine functional groups was studied. The [IrCI6]2− ions bonded to the support were found to undergo spontaneous reduction with decreasing acidity of medium, and an extraordinary mobility was observed for the Ir(IV) ⇄ Ir(III) equilibrium in chemical reactions of the chloro complexes on the sorbent. Spectroscopic measurements did not reveal formation of Ir (IV) or Ir(III) aqua compounds ([Ir(H2O)xCI6−x]x−2 or [Ir(H2O)xCl6−x]x−3) as a result of interaction of the bonded [IrCl6]2− ions with water as the solvent; the final product of hydrolysis of the immobilized [IrCl6]2−ions is an Ir(III) complex with the amine functional groups of the sorbent in the coordination sphere.
Bulk grafting of decyl methacrylate onto poly(vinyl chloride) in the presence of a lead carboxylate stabilizer
Authors: Gressier J. C. , Levesque G. , Brault D.
Published: April 2003

In order to improve the permanence of the plasticizer in a poly(vinylchloride) (PVC) compound we have studied the free radical polymerization and grafting of decyl methacrylate (DMA) onto PVC in the presence of a lead stabilizer. The influence of different parameters has been investigated and homogeneous PVC‐g‐PDMA copolymers have been obtained. Their molecular weights and the glass transition temperatures were consistent with the grafted nature of the copolymers.
Studies on hexolic anhydride based polyesters, 1. Characterization and sequence determination in hexolic based copolyesters by 1H‐ and 13C‐NMR
Authors: Sivasamy P. , Palaniandavar M. , Vijayakumar C. T.
Published: April 2003

The copolyesters and terpolyesters containing maleic or phthalic anhydride and 5,6,7,8,10,10‐hexachloro‐3a,4,4a,5,8,8a,9,9a‐octahydro‐5,8‐methanonaphtho‐[2,3‐c]‐furan‐1,3‐dione (‘hexolic anhydride’) with 2‐butene‐1,4‐diol and 2,3‐dichloro‐2‐butene‐1,4‐diol are synthesized by azeotropic condensation technique. The 1H‐ and 13C‐NMR spectra of these polyesters are recorded and the chemical shifts for the corresponding nuclear magnetic atoms are assigned. A good correlation exists between the observed and theoretically calculated chemical shift values. The sequence distribution, the randomness factor, and the number‐average sequence length of each anhydride monomer unit are calculated using 1H‐ and 13C‐NMR spectra. It is found that both methods give identical results for the same copolyesters and terpolyesters. The results indicate that the copolyesters follow Bernoullian statistics and the terpolyesters correspond to alternative copolyesters.
Zur charakterisierung von polymerfilmen und lichtleitfaserummantelungen aus additionsvernetzendem siliconkautschuk
Authors: Häusler Karl‐Georg , Hummel Klaus , Arndt Karl‐Friedrich , Bartz Heidrun
Published: April 2003

Das Vernetzungsverhalten des additionsvernetzenden Silicons Wacker SilGel 600 wurde im Bereich von 50 bis 90°C in Abhängigkeit von der Heizzeit untersucht. Quellungsmessungen an dünnen Polymerfilmen auf Spezialpapier (Pecozet Z10) gestatten eine Verfolgung des in wenigen Minuten bis zum Quellungsgleichgewicht ablaufenden Quellprozesses, die Auswahl eines geeigneten Quellmittels und die schnelle Ermittlung der Temperaturabhängigkeit des Quellungsgrades Q. Neben Q sind der „Löslichkeitsparameter”︁ des Polymernetzwerkes, die Geschwindigkeitskonstanten und die Aktivierungsenergie des Vernetzungsprozesses zugänglich. Bei der Kombination der Quellungsmessungen mit einer Bestimmung des Hugginsschen Wechselwirkungsparameters kann auch die Vernetzungsdichte der Polymerfilme ermittelt werden.

Auf der Basis dieser Untersuchungen konnte eine schnelle Methode zur Charakterisierung der Ummantelung von Lichtleitfasern entwickelt werden. Die zylindrischen Polymerfilme lösen sich während der Quellung in Toluol(25°C) vom Glaskern. Nach 5 min kann der Quellungsgrad der Ummantelung bestimmt werden.
Halogenation of polymers by dichlorodifluoromethane
Authors: Das Partha S. , Adhikari Basudam , Maiti Sukumar
Published: April 2003

Fluorination of polyethylene and polyvinyl alcohol was carried out by dichloro‐difluoromethane under cobalt‐60 gamma radiation and under electric spark discharge. The effect of temperature, reaction time, catalyst, inert diluent etc. was studied. Simultaneous chlorination of the polymer samples was observed along with fluorination. The extent of fluorination under electric spark discharge is usually higher than that under gamma radiation. Again, the extent of chlorination is higher than that of fluorination in both the cases. The extent of fluorination as well as chlorination is the highest in case of polyvinyl alcohol.
Studies on cellulose acetate phthalate: Estimation of mark‐houwink‐kuhn‐sakurada constants and viscosity‐temperature relationship
Authors: Patel Chandrakant P. , Trivedi Harikrishna C. , Patel Kanti C. , Patel Raman D.
Published: April 2003

Cellulose acetate phthalate (CAP) having an acetyl content of 19.5 wt.‐% and a phthalyl content of 21.4 wt.‐% was prepared and fractionated into five fractions of regularly decreasing molecular weight. The values of the number average molecular weight (M̄n) of these fractions were measured in 0.05 N NaHCO3 by the help of high‐speed membrane osmometer. The intrinsic viscosity [η] values for all the fractions of CAP in 0.05 N NaHCO3 were also determined at different temperatures. The Mark‐Houwink‐Kuhn‐Sakurada equation was applied to the obtained results and the [η]‐M̄n relationships for CAP have been established. The results of the values of v suggest that CAP is a stiff polymer. The temperature dependence of the viscosity of dilute CAP solutions has been described by an Arrhenius expression according to Moore's treatment. The activation energy of flow was found to depend on both concentration and molecular weight through an empirical parameter (Ke). The Ke value obtained for CAP also indicates that CAP is a rigid polymer.
The coupling mechanism of benzotriazole pre‐treated copper metal and epoxy resin
Authors: Xue Gi , Wu Peiyi , Dai Qinpin , Cheng Rongshi
Published: April 2003

Improved adhesion of epoxy resin to copper metal has been achieved by pre‐treating copper with benzotriazole solution. The coupling mechanism and the interfacial reactions have been investigated by using X‐ray photoelectron and FTIR spectroscopies, and differential scanning calorimetry. It was found that benzotriazole reacted with copper metal in the presence of oxygen to form benzotriazolato Cu(I) and bis(benzotriazolato) Cu(II), which covered the surface of copper metal in a shape of polymeric thin layer. As the pre‐treated copper was heated with epoxy compound, it could induce the crosslinking to form interfacial chemical bonds.
N‐bromo‐poly(styrene‐co‐divinylbenzene) sulphonamide metal salts. Synthesis and basic properties
Authors: Bogoczek Romuald , Kociołek‐Balawejder Elżbieta
Published: April 2003

Macromolecular pendant group N‐monobromosulphonamide metal salts SO2NBr−M+ having a macroporous styrene‐divinylbenzene matrix structure have been obtained by two methods:

(a) by the action of aqueous metal hypobromites on the appropriate macromolecular pendant group sulphonamide, and

(b) by the action of an aqueous metal bromide on the appropriate macromolecular N‐chlorosulphonamide metal salt.

In each case the sodium salt product was obtained with a 100% functional yield and it contained 2.1 mmol.g−1 SO2NBr−Na+ groups, i. e., 4.2 meq · g−1 of active bromine. The stability of the resin was investigated in the range 20–100°C in the dry state as well as in aqueous media.

A thermoanalysis (TG, DTG, and DTA curves) was carried out up to 1000°C and its course was interpreted. The resin has brominating, oxidative, microbiocidic, and ionexchanging properties. It reacts in a reversible way: after the loss of the active bromine, it can be reactivated again.
Charge transfer copolymerisation and characterization of 2‐vinylpyridine with methylmethacrylate and ethylmethacrylate
Authors: Bixamaiah B. , Rao P. Raghunath , Sundaram E. V.
Published: April 2003

Copolymers of 2‐vinylpyridine (2‐VP) with methylmethacrylate (MMA) and ethylmethacrylate (EMA) were synthesized by a charge transfer mechanism using a mixture of n‐butylamine (n‐BA) and carbon tetrachloride (CCl4) as the initiator in dimethyl sulphoxide (DMSO) at 60°C. The copolymers were characterized by IR and 13C NMR spectroscopy. The percentage composition of the copolymers was established by elemental analysis. The monomer reactivity ratios (r1, r2) of 2‐VP‐co‐MMA and 2‐VP‐co‐EMA copolymers were determined by both Fineman‐Ross (F‐R) and Kelen‐Tüdős (K‐T) methods: r1 (2‐VP) = 0.30 ± 0.02, r2 (MMA) = 1.20 ± 0.02 and r1 (2‐VP) = 0.71 ± 0.02, r2 (EMA) = 0.63 ± 0.03 by F‐R method. While r1 (2‐VP) = 0.30 ± 0.04, r2 (MMA) = 1.21 ± 0.04, and r1 (2‐VP) = 0.70 ± 0.03, r2 (EMA) = 0.63 ± 0.03 by K‐T method. These values indicate that the system follows random distribution of the monomeric units.
Chemical synthesis of processible electrically conducting poly(3‐dodecylthiophene)
Authors: Nalwa Hari Singh
Published: April 2003

The chemical synthesis of poly(3‐dodecylthiophene) is reported. The polymer was characterized by 1H‐NMR, IR and UV absorption spectroscopic techniques. The room temperature electron spin resonance spectrum yielded a g value of 2.0091 and a linewidth of 6.60 Gauss. The solution cast polymer films after doping with iodine exhibited an electrical conductivity of 12 S/cm.
Macroporous membranes, I. Reactive macroporous membranes based on glycidyl methacrylate‐ethylene dimethacrylate copolymer for high‐performance membrane chromatography
Authors: Švec F. , Jelínková M. , Votavová E.
Published: April 2003

Macroporous membranes were prepared by the radical polymerization of the organic phase, carried out in bulk, opposite to the usually employed suspension radical synthesis of macroporous beads. The properties of the membranes, such as porosity, specific surface area, pore size and distribution and others, approach those of the beads and can be modified by using the same procedures. Water permeability of the membranes is the property important with respect to their application. Dependences of permeability on the polymerization time, concentration of the crosslinking agent in the polymerization mixture, membrane thickness and the polymerization procedure were determined.
Highly active peroxides in the radical polymerization of ethylene under high pressure. Properties of the polymers
Authors: Luft Gerhard , Dorn Max
Published: April 2003

Using highly active peroxide initiators, a number of polyethylene samples were prepared at low temperatures of 70–140°C and a pressure of 1900 bar. The average molecular weight and the melt flow index were adjusted by adding propionaldehyde as modifier. The characteristic properties of the samples as regards the molecular weight distribution, the average molecular weight, the frequency of long chain branching, the crystallinity and the density were determined.

As expected, the polymers are characterized by density values of more than 0.955 g/ml and crystallinity values of 65–80% which are characteristic of PE‐HD. The molecular weight distribution, too, remains within narrow limits. On the other hand, rather surprisingly, a relatively high frequency of long chain branching typical of PE‐LD is obtained.

The investigation of the phase behaviour has shown that polymerization under high pressure at temperatures above 115–118°C takes place in the homogeneous range. The samples polymerized in the transition zone between the single and the two phase area exhibit maximum crystallinity and melt enthalpy. The frequency of long chain branching passed through a minimum.
The effect of viscosity of polyethylene on the evolution of phase structure during the mixing of polypropylene/EPDM elastomer/polyethylene blends
Authors: Fortelný Ivan , Navrátilová Edita , Kovář Josef
Published: April 2003

The dependences of phase structure and notch impact strength on conditions of mixing have been compared for the binary blend PP/EPDM and for two ternary blends PP/EPDM/PE possessing different viscosities of polyethylene. At low rates and short times of mixing a phase structure with pronounced inhomogeneities (particles of the dispersed phase having diameters of tens μm) is formed in all blends. Conditions of mixing needed for the formation of a homogeneous phase structure (with particles having diameters of several μm) depend on the average viscosity of the components forming the inclusions (EPDM elastomer or EPDM elastomer/polyethylene). Depending on the conditions of mixing and on the rheological properties of components, substitution of one part of the EPDM elastomer with PE may lead to an increase or decrease in the impact strength of the final blend.
Gelpermeationschromatographie von poly(vinylidenfluorid)
Authors: Pastuska Gerhard , Just Ulrich
Published: April 2003

Es wird ein Verfahren zur Gelpermeationschromatographie von Poly(vinylidenfluorid) beschrieben. Als Lösemittel wird N,N‐Dimethylformamid bei 50°C an μ‐Styragelbzw. PLgel‐Säulen verwendet.

Chemische Reaktionen des PVDF können erfaßt werden.
Encapsulating polymerization of titanium dioxide
Authors: Haga Yutaka , Watanabe Takanobu , Yosomiya Ryutoku
Published: April 2003

Titanium dioxide was encapsulated in polymethyl methacrylate and polystyrene by the emulsion polymerization process, and the influence of various polymerization conditions such as the monomer and initiator concentrations and amounts of titanium oxide on the polymerization behavior was investigated. In the polymerization mixture where the end of the polymer chain and the metal oxide surface are oppositely charged, unextractable polymer is formed well. The encapsulating polymers show special structures with high molecular weight and high density.
Thermooxidative degradation of PVC in solution in the presence of metal stearate stabilizers
Authors: Iván Béla , Turcsányi Béla , Kelen Tibor , Tüdős Ferenc
Published: April 2003

Detailed research has been carried out to determine the effect of metal stearates (PbSt2, CdSt2, BaSt2, CaSt2, and ZnSt2) on the thermooxidative degradation of PVC in inert dilute solution. The induction periods of free HCl evolution increase in the presence of PbSt2, CdSt2, CdSt2, BaSt2, and CaSt2, while ZnSt2, due to ZnCl2 formation, leads to fast HCl loss without induction period. The induction periods are much shorter than those obtained during thermal degradation, but the relative order of effectiveness of these stabilizers is the same as in inert atmosphere: PbSt2 > CdSt2 > BaSt2 > CaSt2 > ZnSt2. After the induction period, the initial rates of free HCl evolution decrease as metal stearate concentrations increase. Surprisingly, this dependence is independent of the kind of metal. At higher stabilizer concentrations, the initial rates of free HCl loss during the thermooxidative degradation approach the initial dehydrochlorination rate of thermally degraded PVC. As UV and visible spectra indicate, there is a sharp change in the normalized integral absorption versus time plots at the end of the induction periods in the presence of PbSt2, CdSt2, and BaSt2. Based on these experimental results, it has been concluded that effective metal stearates have manifold roles in the course of PVC stabilization under thermooxidative conditions. The main role of these compounds is not the replacement of labile structures and HCl‐scavenging, but the blocking of the rapid zip‐elimination is the most important event of the stabilization process. However, this blocking is reversible, which becomes effective mainly right after the consumption of the metal soaps (reversible blocking mechanism). Another important effect of these stabilizers is that they destroy peroxides and/or peroxy radicals (antioxidant effect).
Beitrag zur Aufklärung der Morphologie von segmentierten Polyurethanen
Authors: Foks Janina , Naumann Irene , Michler Georg H.
Published: April 2003

Verschiedene Polyester‐Polyurethane mit einem Anteil der Hartsegmente von 22 bis 100 Gew.‐% wurden hinsichtlich ihrer übermolekularen Strukturen elektronenmikroskopisch analysiert. Hierzu wurden sowohl Kryodünnschnitte und Lösungsfilme mit der Höchstspannungs‐Elektronenmikroskopie als auch Abdruckfilme und chemisch kontrastierte Ultradünnschnitte mit der konventionellen Transmissions‐Elektronenmikroskopie untersucht. In allen Proben wurde eine vielschichtige Morphologie gefunden, die aus mindestens vier unterschiedlichen Anteilen oder Phasen besteht. Dazu gehören Sphärolithe mit zentralsymmetrischem Aufbau, Garben mit einer Fächerstruktur, Fibrillen, Lamellen sowie Domänenstrukturen. Mit abnehmendem Hartsegmentanteil treten deutliche Änderungen in der Ausbildung und in der Häufigkeit dieser Strukturen auf. Die Existenz der sog. Mikrodomänen wird in Verbindung mit der angewandten chemischen Kontrastiertechnik diskutiert.
Studies on polycarbonate‐viton GF blends
Authors: Choudhary Veena , Mehta Rakesh
Published: April 2003

The effect of addition of different amounts of Viton GF, a fluoroelastomer, on the properties of polycarbonate (PC) was investigated. A significant improvement in impact strength (ca. 100%) was observed on addition of 20 wt.‐% of Viton GF. Thermal and dynamic mechanical behaviour of the blends was also investigated.

The morphology of these blends was studied by scanning electron microscopy which revealed an uniform distribution of rubber cavities in polycarbonate matrix. The number of rubber cavities increased with increase of rubber content. Erosive wear studies were carried out on compression moulded sheets of PC and PC/Viton GF blends using a sand blasting rig. The effect of impact angle and the amount of abrasive used on the erosive behaviour was investigated. Polycarbonate showed a maximum erosion at an impact angle of 30°. A reduction in specific erosion was observed with increasing concentration of elastomer in the blends.
Synthesis and studies of ultraviolet light absorbing resins
Authors: Menon Susha R. , Patel Chetan G. , Parmar Jayant S.
Published: April 2003

Ultraviolet absorbers were prepared by condensation of 2‐hydroxy‐4‐methoxy benzophenone with formaldehyde using p‐toluene sulfonic acid as catalyst. For comparative study 2,4‐dihydroxy benzophenone was also condensed with formaldehyde under similar conditions. These resins were characterized by determining their molecular weights by non‐aqueous conductometric titration and vapour pressure osmometry, the structural features by IR and NMR study, the thermal properties by TGA, and the range of UV‐absorbance from UV‐spectra.
Synthesis and characterization of poly(isopropyl methacrylate‐co‐acrylamide)
Authors: Srinivasulu B. , Rao P. R. , Sundaram E. V.
Published: April 2003

Free radical copolymerization of isopropyl methacrylate (IPMA) and acrylamide (AA) was carried out in the presence of 2,2′‐azoisobutyronitrile in dimethyl formamide at 60°C. The copolymer compositions were established by elemental analysis. The copolymerization reactivity ratios were determined by both Fineman‐Ross (F‐R) and Kelen‐Tüdős (K‐T) methods. The copolymers were characterized by IR, 1H‐NMR, thermal and dielectric studies. Glass transition temperature values (Tg) have been determined by DSC.
Effect of reactive diluents on curing behaviour and thermal stability of urethane methacrylate
Authors: Tyagi A. K. , Choudhary V. , Varma I. K.
Published: April 2003

Urethane methacrylate monomer (UMA) containing methacryloyl group was prepared from toluylene diisocyanate (TDI), 2‐hydroxyethyl methacrylate (HEMA), and ethylene glycol by a two step reaction. Curing was investigated using benzoyl peroxide and N,N‐dimethylaniline as initiator system. The effect of concentration of initiator and reactive diluents, i.e., methyl methacrylate and styrene, on gel point was determined. An increase in gel time was observed by increasing the concentration of reactive diluent or decreasing the concentration of initiator. In TG traces (recorded in nitrogen atmosphere) of cured resins two step decomposition was observed in the temperature range of 230 to 500°C. The thermal stability of copolymers was influenced by the nature and content of reactive diluent.
Natural weathering of polyolefins. Kinetics of the photooxidation
Authors: Severini Febo , Gallo Raffaele , Ipsale Salvatore
Published: April 2003

The rate constants of the natural degradation processes of low density polyethylene and polypropylene films have been calculated on the basis of the molecular weights of weathered samples. Moreover, the optical densities, obtained by means of IR spectroscopy, indicate that the formations of carbonyl and vinyl groups are zero‐order reactions.
Hydrophobic recovery and misting behavior of plasma treated PS and PC surfaces
Authors: Morra M. , Occhiello E. , Garbassi F.
Published: April 2003

Oxygen plasma treatments of transparent polymers such as polystyrene (PS) and polycarbonate (PC) were performed. Then the hydrophobic recovery of treated surfaces and its effect on their misting behavior was studied. Surface investigations, such as XPS and water contact angle measurements, were combined with the characterization of misting behavior by light transmission methods.

In the case of PS it was found that the composition and wettability of the surface layer is insensitive to extraction in water. Hydrophobic recovery leads to decreases of advancing angles upon aging by a mechanism involving macromolecular motions. Misting follows rather closely the behavior of water advancing angles.

Oxygen plasma treatment of PC surfaces induces the formation of low molecular weight species which can be extracted by water. Both non‐extracted and extracted surfaces were found to undergo hydrophobic recovery with the same mechanism observed in the case of PS. In both cases the misting behavior can be well explained on the basis of wettability.
Untersuchungen zum Einsatz von technischen Kohlenwasserstofffraktionen als Monomerquelle und Lösungsmittel für die Dienpolymerisation
Authors: Gebauer Ulrich , Reiche Frank , Gehrke Klaus
Published: April 2003

Es werden Untersuchungen zur Herstellung von modifiziertem cis‐1,4‐Polybutadien vorgestellt. Mittels Copolymerisation von Butadien mit Bestandteilen einer C5+‐Pyrolysefraktion, vornehmlich dem Isopren, sollte eine Modifizierung im Eigenschaftsbild des Polybutadiens angestrebt werden. Zur Polymerisation eingesetzt wurden das Ziegler‐Natta‐Katalysatorsystem Nickel(II)ethylhexanoat/Titantetrachlorid/Aluminiumtriethyl sowie das Lösungsmittel Toluol.

In Vorbereitung der angestrebten Copolymerisation wurde mit dem genannten Katalysatorsystem die Polymerisierbarkeit von Bestandteilen der C5+‐Fraktion ausgetestet. Ziel dieser Untersuchungen waren eine Optimierung der Polymerisation auf höhere Ausbeuten an Polymeren über eine Variation der Konzentration der Katalysatorbestandteile und die Bestimmung der Zusammensetzung der Polymeren.

Die Copolymerisationen des Butadiens mit Bestandteilen der C5+‐Fraktion wurden mit dem Ni/Ti/Al‐Katalysatorsystem bei zwei verschiedenen Konzentrationsverhältnissen der Katalysatorkomponenten durchgeführt. Über eine Bestimmung der Restmonomerzusammensetzung mittels Kapillar‐Gaschromatographie konnten Angaben zur Zusammensetzung der Copolymerisate hinsichtlich der wichtigsten Bestandteile erhalten werden.
Composites of silane treated cellulosic fibers and high density polyethylene
Authors: Raj R. G. , Kokta B. V.
Published: April 2003

Silanes with different functional groups (vinyl, acryl and amino) were used to pretreat the wood fiber. Composites were made with high density polyethylene (HDPE) and silane pretreated wood fibers at various filler levels (0 to 40 wt.‐%). The effects of silane treatment on fiber‐matrix adhesion and fiber dispersion were studied. The characterization of fiber‐matrix interaction was done by IR. The influence of silane concentration, filler content and the nature of wood fiber on mechanical properties (tensile and impact strength) of the composites were examined.
The application of DSC in identification of LDPE/LLDPE blends mulching film
Authors: Wu Xiaobing , Chen Jiaqi , Zeng Xingrong
Published: April 2003

The mulching film samples of known and unknown composition LDPE/LLDPE blends have been analysed and the film samples of unknown composition have been identified by means of differential scanning calorimetry (DSC). The relationships between composition of film samples and melting enthalpy peak in their DSC thermograms have been discussed. The working curve for determining the composition has been given. The experimental results show that DSC is a quick, effective and accurate method for the analysis of main composition of LDPE/LLDPE blends mulching films.
The effect of PP and EPR grafted with acrylic acid on the properties and phase structure of polypropylene/elastomer/short glass fibre composites
Authors: Kelnar Ivan
Published: April 2003

Composites comprising polypropylene/elastomer/short glass fibre in which acrylated polypropylene (AcPP) or acrylated ethylene‐propylene elastomer (AcEPR) were used to raise the interfacial adhesion were investigated. These agents cause a change in mechanical properties, and predominantly a rise in strength, not only due to an improved matrix‐fibre adhesion, but also by affecting the phase structure of the matrix in the surroundings of the fibres. Better results were obtained in the case of AcPP, but—surprisingly enough—the impact strength was lower with AcEPR than with a composite containing unfunctionalized components.
Lichtinduzierte Polymer‐ und Polymerisationsreaktionen, 47. Photopolymersysteme mit α‐sulfonyldesoxybenzoinen als initiatoren
Authors: Timpe Hans‐Joachim , Müller Uwe , Möckel Peter
Published: April 2003

α‐Sulfonyl deoxybenzoines are formed by the reaction of desylchloride with sodium arylsulfinates in good preparative yields. The photolysis of these compounds proceeds with quantum yields of about Φin = 0.50. Compared to other photoinitiators, α‐sulfonyl deoxybenzoines polymerize methylmethacrylate in acetonitrile solution with moderate polymerization quantum yields only. On the contrary, the yellowing of cured polyester resins using these compounds as photoinitiators is much smaller.
Soluble maleimide prepolymers containing 1,3,5‐triazine groups as composite resin matrices. Synthesis, characterization, and evaluation
Authors: Dolui Swapan K.
Published: April 2003

Low molecular weight amine‐terminated monomaleimide prepolymers containing 1,3,5‐triazine groups as well as ether linkages were synthesized by reacting benzophenone tetracarboxylic dianhydride, diamines having 1,3,5‐triazine group and maleic anhydride. These reactive prepolymers are soluble in low boiling solvents such as chloroform, tetrahydrofuran etc. They were characterized by elemental analyses, IR and NMR spectroscopy, vapour pressure osmometry, and viscosity. On heating at 180–190°C these prepolymers undergo simultaneous chain extension by Michael addition reaction and crosslinking by mutual reaction between their amine‐terminated and maleimide‐terminated ends. The cured polymers are thermostable and the thermal behaviour was studied by TGA, DTA, and isothermal aging. Laminates fabricated using these prepolymers and carbon fiber as reinforcing agent were evaluated by their flexural strength and interlaminar shear strength.
Studies on new non‐shrinking, thermally stable araldite‐type photopolymers with pendent arylacryloyl‐groups. I. Photoreaction of some aryl acrylic‐acid methyl esters in solution
Authors: Müller Harald , Nuyken Oskar
Published: April 2003

Aryl acrylic acids, e. g. furyl acrylic acid or thienyl acrylic acid are readily formed by the Knoevenagel condensation reaction of arylcarbaldehydes and malonic acid in pyridine. Esterification of these acids with methanol/sulfuric acid gives the corresponding aryl acrylic acid methyl esters in good yields. In methanolic solution these methyl esters isomerize upon irradiation (λ 280 nm). No photodimerization was observed. Kinetic data are given.
Antioxidants and stabilizers, CXIII. Oxidation products of the antidegradant ethoxyquin
Authors: Taimr Luděk , Prusíková Miluše , Pospíšil Jan
Published: April 2003

In connection with the study of the mechanism of antioxidant action of 6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline (ethoxyquin, I) and of its ecological responses in stabilized polymers we studied its oxidation with some selected agents and the properties of products thus obtained. The oxidation of I with silver oxide or lead dioxide proceeds by two main routes. One of them leads to 8‐(6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydro‐1‐quinolinyl)‐6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline (IV), which is further oxidized to the blue compound 8‐(6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydro‐1‐quinolinyl)‐2,2,4‐trimethyl‐6‐quinolone (IX). In the second route position 6 is attacked and 2,2,4‐trimethyl‐6‐quinolone (VII) is formed, which is stable under the conditions used, but is oxidized further with m‐chloroperbenzoic acid, giving rise to 2,2,4‐trimethyl‐6‐quinolone‐N‐oxide (VIII). The oxidation of ethoxyquin with potassium permanganate also gives rise to dimer IV and not to 1,1′‐bis(6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline) (III) reported in the literature. Potassium nitrosodisulfonate oxidizes I with formation of 6‐ethoxy‐2,2,4‐trimethyl‐8‐quinolone (X). The oxidation of ethoxyquin with m‐chloroperbenzoic acid gives rise to 6‐ethoxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline‐N‐oxide (V) and dimer IV. Nitroxide V was obtained in the crystalline state. In the presence of acids, and particularly on the surface of silica gel it decomposes to ethoxyquin and nitrone VIII. Nitroxide V is readily reduced to the starting ethoxyquin. The transitionally formed 6‐ethoxy‐1‐hydroxy‐2,2,4‐trimethyl‐1,2‐dihydroquinoline (XIV) readily disproportionates to I and V.
Matériaux composites à base de bois rétifié, III. Etude de l'influence de la granulométrie des charges lignocellulosiques
Authors: Revenu P. , Guyonnet R. , Bourgois J.
Published: April 2003

Divers matériaux composites à base de peuplier rétifié ou naturel et de résine polyester insaturée ont été préparés par moulage. L'influence de la granulométrie de la charge a été étudiée sur quelques propriétés physico‐chimiques (densité, reprise d'humidité, dureté) ou mécaniques des matériaux obtenus. La densité et la reprise de masse en milieu humide sont toujours plus faibles si la charge est traitée thermiquement sous atmosphère inerte. Par contre, la dureté des composites issus du peuplier naturel est plus importante. Les propriétés mécaniques sont inférieures si la charge est rétifitée.

Si la charge lignocellulosique est traitée thermiquement, il est possible d'optimiser les trois paramètres: densité, reprise d'eau et propriétés mécaniques; la granulométrie optimale du peuplier est ainsi comprise entre 0,75 et 1,5 mm.

Les résultats obtenus sont expliqués en tenant compte des propriétés physico‐chimiques des charges et des interactions existant entre la résine polaire et le bois.
Phosphination of styrene‐bromostyrene‐divinylbenzene terpolymers
Authors: Bacquet M. , Le Maguer D. , Caze C.
Published: April 2003

The phosphination of styrene‐bromostyrene‐divinylbenzene terpolymers as a function of their textural and chemical characteristics has been studied. A small decrease of both specific area and porous volume with phosphination was observed. Chemical analysis showed the presence of side reactions like reduction of the halogen, addition on the double bond, and crosslinking reaction involving the different functional groups. The phosphorous distribution was inhomogeneous; this was attributed to a difference of crosslinking density in the beads due to the particular morphology of this type of support.
Creep studies of casein films grafted with acrylonitrile and n‐butyl methacrylate
Authors: Somanathan N. , Usha R. , Ranganathan T. S. , Sanjeevi R.
Published: April 2003

Casein was grafted with a binary mixture of acrylonitrile and n‐butyl methacrylate and cast into films. The creep behaviour of the films was studied at different temperatures and at various applied stress levels. The extension increases with the increase of applied stress at all temperature.
Grafting reaction of methylmethacrylate onto EPR and EPDM rubbers. Toughening effects of graft copolymers on polycarbonate and poly(methylmethacrylate)
Authors: Severini Febo , Pegoraro Mario , Di Landro Luca
Published: April 2003

The grafting reaction of methylmethacrylate was done using EPR or EPDM rubbers swollen by a minimum amount of cyclohexane in the presence of benzoyl peroxide or azoisobutyronitrile and of the monomer at 80°C. The yield of the grafting reaction was evaluated as function of the added initiator and of the unsaturation content in the rubber. The products of the grafting reaction were used to obtain blends with poly(methylmethacrylate) and with polycarbonate. The mechanical properties indicate that a good toughening effect is obtained even if molding is done by simple compression technique.
Determination of micropore concentration and size distribution in carbon fibres by the saxs method
Authors: Włochowicz Andrzej , Rabiej Stanisław
Published: April 2003

The parameters of pores in carbon fibers made from poly(acrylonitrile), such as the volume fraction of pores, the correlation length, the specific surface area etc. were determined by SAXS. The pore size distribution functions were evaluated using the methods of Glatter and Jellinek.
Mehrphasensysteme auf basis von fluorpolymeren, 1. Modifizierung von füllstoffoberflächen
Authors: Schmidt E. , Schäfer E. , Semjonow V. , Brandrup J.
Published: April 2003

In Mehrphasensystemen aus Poly(tetrafluorethylen) (PTFE) und Glasfasern besteht praktisch keine Haftung zwischen Matrix und Füllstoff. Es wurde der Frage nachgegangen, ob es Wege zur Verbesserung der Grenzflächenhaftfestigkeit gibt und ob diese Verbesserungen ausreichen, eine Verstärkung, d. h. Anhebung der Reißfestigkeit bei gleichzeitigem Rückgang der Dehnung des Gesamtsystems zu erzielen.

In diesem ersten Teil wird den theoretischen Voraussetzungen und der Modifizierung der Füllstoffoberflächen mittels Dispersionsbeschichtungen sowie Plasmaätzen und Plasmapolymerisation nachgegangen.

In einem zweiten Teil werden Möglichkeiten zur Verbesserung der Grenzflächenhaftung durch Modifizierung der Polymer‐Oberfläche und durch Additive untersucht.
Mehrphasensysteme auf basis von fluorpolymeren, 2. Modifizierung der polymermatrix
Authors: Schmidt E. , Schäfer E. , Semjonow V. , Brandrup J.
Published: April 2003

In Mehrphasensystemen aus Poly(tetrafluorethylen) (PTFE) und Glasfasern besteht praktisch keine Haftung zwischen Matrix und Füllstoff.

Es wurde die Frage untersucht, ob es Methoden gibt, diese Grenzflächenhaftung zu erhöhen und welchen Einfluß diese Erhöhung auf die Eigenschaften des Verbundsystems hat.

In dem hier vorliegenden Teil 2 wird speziell auf den Einfluß der Modifizierung der Polymeroberfläche und des Zusatzes von Additiven eingegangen.
Dependence of properties of aqueous resols upon conditions of synthesis
Authors: Rubeš Miroslav , Eichler Josef
Published: April 2003

Phenol formaldehyde resins of resol type were prepared under molar ratio phenol: formaldehyde: calcium hydroxide 1:2.7:0.1. The reaction products contained in all cases about 3.8% free formaldehyde and 1.5% free phenol. A 36% solution of formaldehyde was used for synthesis. The course of synthesis, expressed by drop of free formaldehyde contents in the reaction mixture, is presented. In aqueous resol solutions, prepared by this way, the decrease of miscibility with water was examined during storage at 10°C. It was found that the resol synthesized at lower temperature had better shelf life than that prepared at higher temperature. The presented results are of practical importance in the cases where compatibility with water is a significant processing parameter.
Nucleophilic substitution reaction of ethanolamine onto poly(phenyl acrylate) and substituted poly(phenyl acrylate)s
Authors: Baskaran D. , Rajalingam P. , Radhakrishnan G.
Published: April 2003

The nucleophilic substitution reaction of differently substituted phenoxy groups with ethanolamine in various poly(phenyl acrylate)s was investigated in dioxane at 60, 80, and 100°C. The conversion, as determined from IR‐ and 1H‐NMR spectroscopy and elemental analysis, depends on the temperature and the kind of substituents at the phenyl ring.
Studies on new non‐shrinking, thermally stable araldite‐type photopolymers with pendent aryl acryloyl‐groups. II. Photoreaction of some arylacrylic‐acid methyl esters in the liquid state
Authors: Müller Harald , Nuyken Oskar
Published: April 2003

Liquid aryl acrylic acid methyl esters, e.g. furan acrylic acid methyl ester and thienyl acrylic acid methyl ester, were UV‐irradiated (λ ≥ 280 nm) at a temperature of 2°C above their melting points. IR‐methods were used in order to monitor the photoreactions which are of a second order kinetics. The application of GC‐MS indicated that dimers, trimers and tetramers, but no polymers were formed under the chosen conditions.
Einfluß der Herstellungsbedingungen auf die Eigenschaften von Precursor‐Polyacrylnitrilfasern und daraus erzeugten Kohlenstoffasern
Authors: Mikołajczyk Teresa , Kamecka‐Jedrzejczak Katarzyna , Krucińska Isabella
Published: April 2003

C‐Fasern sind wegen ihrer herausragenden Festigkeit und ihres hohen Moduls für die verschiedensten technischen Einsatzgebiete von großer Bedeutung. Deshalb werden viele Anstrengungen unternommen, Fehlstellen in den Fasern, die die Eigenschaften praktisch begrenzen, zu minimieren. Eine deutliche Hilfe hierbei ist die Optimierung der Struktur der PAN‐Fasern, die zu C‐Fasern weiterverarbeitet werden. In der vorliegenden Arbeit wird für naßgesponnene PAN‐Fasern beschrieben, wie es durch Aufteilung der Verstreckung und angemessene Temperaturführung gelingt, Faser‐Strukturen einzustellen, die zu besseren C‐Faser‐Eigenschaften führen. Die praktischen Ergebnisse werden durch Strukturanalysen belegt.
Water‐soluble polyamides as potential drug carriers. III. Relative main‐chain stabilities of side chain‐functionalized aspartamide polymers on aqueous‐phase dialysis
Authors: Neuse Eberhard W. , Perlwitz Axel G. , Schmitt Siegfried
Published: April 2003

A total of 12 water‐soluble N‐substituted polyaspartamides, some of these previously reported, are synthesized from the polysuccinimide 1 by nucleophilic ring opening and are characterized microanalytically and spectroscopically. The relative hydrolytic mainchain stabilities of the product polymers are evaluated in dialysis tests (6000–8000 molecular‐mass cut‐off) performed over periods of 24–48 h in aqueous solution in an effort to assess their suitability as homo‐ or copolymeric carriers for aqueous‐phase coupling to biologically active agents. In agreement with previous work, resistance to main‐chain degradation is found to be very poor with the N‐(2‐aminoethyl)‐ and N‐(3‐aza‐6‐oxahexyl)‐substituted derivatives 2a and 2b (10–20% recovery after 48 h), and moderately poor with the 3,6‐diazahexyl‐substituted 2c (45% recovery). These three representatives, hence, cannot efficaciously be subjected to aqueous‐phase drugcoupling reactions save for short exposure times. Good to excellent stabilities, however, with product recoveries in the 70–95% range, are shown by the remainder of polymers, 2d–21, all of which are characterized by the absence of primary or secondary amino groups in the side chains separated from the amide nitrogen atom by less than three carbon atoms. Polyaspartamides selected from this group for their promising drug coupling potential include the N‐(3‐aminopropyl)‐, N‐(3‐aminohexyl)‐, and N‐(2‐ṕiperazinylethyl)‐substituted types 2e, 2f and 2h possessing primary or secondary amine functions as anchoring sites, and the N‐(2‐(dimethoxy)ethyl) derivative 21, of interest as the precursor to a formyl‐functionalized carrier polymer. Lastly, the units of 2i and 2j, featuring 3‐(dimethylamino)propyl and 3‐(morpholin‐4‐yl)propyl substituents, lend themselves as solubilizing segments in copolymers that comprise additional repeat units equipped with drug‐anchoring sites.
Tensile properties and morphology of injection‐molded poly(1‐butene)
Authors: Lee Mao‐Song , Chen Show‐An
Published: April 2003

The injection‐molded poly(1‐butene) (PB‐1) is found to be more brittle than the compression‐molded PB‐1. The morphologies of these specimens are examined by use of polarized optical microscopy and scanning electron microscopy (SEM). A skin layer and an oblate spherulitic structure extended to the core region are observed in the injection‐molded PB‐1, while typical spherulites exist in the compression‐molded PB‐1. Below the skin layer of the injection‐molded PB‐1, the fracture surface is found to consist of many aligned strip‐like voids with ribbon edges propagating to the center of the specimen and perpendicular to the flow direction of injection‐molding. Based on these observations, it can be inferred that shear stress induced by the melt flow during the injection‐molding does not only cause the formation of skin layer, but also penetrates deeply into the central region of the injection‐molded specimen causing the formation of oblate spherulites. The oblate spherulitic structure is responsible for the aligned voids during elongation of PB‐1, while the existence of the skin layer and the oblate spherulites in core region is responsible for the brittleness of the injection‐molded PB‐1. The elongation of the injection‐molded PB‐1 is found to be lower than that of the compression‐molded. This can be attributed not only to the presence of the skin layer but also to the oblate spherulites in the core region. The elongation can be improved by annealing at a temperature above the melting point of PB‐1.
Gas chromatographic studies on the compatibility of PVC with a migration resistant plasticizer
Authors: Demertzis P. G. , Riganakos K. A. , Akrida‐Demertzi K. , Kontominas M. G.
Published: April 2003

The technique of inverse gas chromatography (IGC) was used to investigate the thermodynamic miscibility (compatibility) of low molecular weight PVC‐poly(adipate ester) plasticizer mixtures. The polymer‐plasticizer thermodynamic interaction parameters were determined from chromatographic retention data for various low molecular weight volatile solutes (probes) on stationary phase mixtures which covered the entire composition range for each component. Experiments were carried out in the temperature range of 90 to 110°C. The Flory‐Huggins interaction parameter (χ+23) values were found to be dependent on the chemical nature of the probes, the temperature, and the composition of the mixed phase. The results predict a relatively high polymer‐plasticizer compatibility for a wide range of polymer‐plasticizer mixtures (up to approx. 70 wt.‐% of plasticizer). Results were also compared to our own previous data using high molecular weight PVC.
Synthesis and biological activity of chlorinated polyketone resins
Authors: Patel N. Z. , Patel J. N. , Ray R. M. , Patel R. M.
Published: April 2003

Some polyketones were prepared from p‐xylene, chloroacetylchloride, 1,2‐dichloroethane and dichloromethane using anhydrous aluminiumtrichloride and carbon disulfide as solvent. The resins thus obtained have been characterized by IR spectra and number average molecular weight. The thermal properties have been studied by thermogravimetry and differential scanning calorimetry. All the resins were tested for their biological activity against Pseudomonas fluorescens, Bacillus subtilis and Aspergillus niger. The results show that the growth of the tested organisms can be controlled by the polyketone resins.
Preparation and properties of porous particles from trimethylolpropane trimethacrylate
Authors: Reinholdsson Per , Hargitai Tihamér , Isaksson Roland , Törnell Bertil
Published: April 2003

Spherical macroporous particles, intended for use as carrier particles in various types of column operations, were prepared by suspension and microsuspension polymerization of trimethylolpropane trimethacrylate (TRIM), in the presence of various amounts of porogenic agents (toluene or mixtures of toluene and isooctane). The texture and properties of the particles varied markedly with the amount and composition of the porogenic agent, and were also affected by the choice of suspension stabilizer. Macroporous particles were prepared, ranging in total pore volume from 0.4 to 3.6 cm3/g, and in specific surface area from 7 to >450 m2/g. All of the particles contained macropores, and except for those with very low specific surface area, contained a certain fraction of micropores (diameter <60 Å). The presence of micropores could be eliminated completely by decreasing the monomer concentration and increasing the isooctane content of the porogenic agent to 50 wt.‐%. Increasing the isooctane content also resulted in an increase in the total pore volume and a decrease in the tendency of the polymer matrix to swell in toluene. The effect on properties of particles by heat treatment at 130°C and by grafting poly(methyl methacrylate) onto the particles was also studied.

The amount of unreacted double bonds of the particles could be varied by varying the polymerization temperature. The presence of easily accessible double bonds is important as they can be utilized for functionalization of the rigid macroporous particles.
Miscibility of polyarylate/phenoxy/poly(butyleneterephthalate) ternary blends
Authors: Ahn Tae Oan , Lee Sukmin , Jeong Han Mo , Cho Kilwon
Published: April 2003

The phase and miscibility behavior of binary and ternary blends containing polyarylate (PAR), polyhydroxyether of bisphenol A

IUPAC: poly[oxy(2‐hydroxytrimethylene)oxy‐1,4‐phenylene‐isopropylidene‐1,4‐phenylene].

(Phenoxy), and poly(butylene terephthalate) (PBT) were studied. The blends were prepared by solution‐precipitation method and miscibility was examined by DSC and melt transparency. In binary blends, PAR/PBT and Phenoxy/PBT blends show miscibility, while PAR/Phenoxy appeared to be immiscible. However, the miscibility of incompatible PAR/Phenoxy blend was enhanced by addition of PBT. The addition of sufficient amount of PBT caused the ternary blend to have a single glass transition temperature. The shape of miscibility boundary of ternary blend was skewed to the apex of Phenoxy, which was attributed to the better miscibility of PAR/PBT than that of Phenoxy/PBT.