bluuebunny/crossref_metadata_2025 huggingface dataset:
The flocculation of kaolin by cationic polyacrylamides and the effect of cationic surfactant on this process
Authors: McCarron Alison M. , Crispo Sabrina , Smith‐Palmer Truis
Published: August 2002

The flocculation of kaolin suspended in a dilute salt solution was studied as a function of the addition of cationic surfactant and cationic polyacrylamide (CPAM) added separately, consecutively, or simultaneously. Cationic polyacrylamide caused flocculation by bridging when added in low concentrations, but at higher concentrations, charge neutralization became the dominant mechanism and the flocculation rate was highly dependent on the charge density of the polymer. Adsorption of sufficient polymer or surfactant (cetyl pyridinium chloride) prevented immediate adsorption of the other, although surfactant could replace polymer after extended agitation. The adsorption of polymer was greatest when small flocs were formed by charge neutralization or by prolonged shaking. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2382–2389, 2002
Synthesis and characterization of novel copolymers with the trimethylsilyl group for deep‐UV photoresists
Authors: Chiang Wen‐Yen , Lin Yung‐Ching
Published: August 2002

N‐(4‐Acetoxyphenyl) maleimide (APMI) and three kinds of comonomers bearing a trimethylsilyl group were copolymerized at 60°C in the presence of azobisisobutyronitrile (AIBN) as an initiator in 1,4‐dioxane to obtain the three IP, IIP, and IIIP copolymers. These copolymers were removed from the acetoxy group in a transesterification process into new IVP, VP, and VIP copolymers with a pendant hydroxyl group. Two modified processes were adopted to prepare photoresists using these copolymers. The first process involved mixing the dissolution inhibitor, o‐nitrobenzyl cholate, with the new copolymers. Second, o‐nitrobenzyl cholate was introduced into the copolymers using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in dimethylformamide (DMF). The cyclic maleimide structure is responsible for the high thermal stability of these copolymers. After irradiation using deep–UV light and development with aqueous Na2CO3 (0.01 wt %), the developed patterns showed positive images and exhibited good adhesion to the silicon wafer without using any adhesion promoter. The resolution of these resists was at least 0.8 μm and an oxygen‐plasma etching rate was 1/5.3 to that of hard‐baked HPR‐204. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2791–2798, 2002; DOI 10.1002/app.10255
Thermally crosslinkable poly(phenylene sulfide)/poly(ether sulfone)/polymerization of monomer reactant–polyimide blends
Authors: Lai Mingfang , Yang Yuming , Liu Jingjiang
Published: August 2002

The effects of thermally crosslinkable polymerization of monomer reactant–polyimide (POI) on the miscibility, morphology, and crystallization of partially miscible poly(ether sulfone) (PES)/poly(phenylene sulfide) (PPS) blends were investigated with differential scanning calorimetry and scanning electron microscopy. The addition of POI led to a significant reduction in the size of PPS particles, and the interfacial tension between PPS and crosslinked POI was smaller than that between PES and crosslinked POI. During melt blending, crosslinking and grafting reactions of POI with PES and PPS homopolymers were detected; however, the reaction activity of POI with PPS was much higher than that with PES. The crosslinking and grafting reactions were developed further when blends were annealed at higher temperatures. Moreover, POI was an effective nucleation agent of the crystallization of PPS, but crosslinking and grafting hindered the crystallization of PPS. The final effect of POI on the crystallinity of the PPS phase was determined by competition between the two contradictory factors. The crosslinking and grafting reactions between the two components was controlled by the dosage of POI in the blends, the premixing sequence of POI with the two components, the annealing time, and the temperature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2906–2914, 2002; DOI 10.1002/app.10287
Preparation of a self‐compatibility alloy via a seed‐graft concentrated‐emulsion pathway
Authors: Li Hangquan , Du Zhongjie , Huang Haohao
Published: August 2002

A novel polymerization procedure, the concentrated‐emulsion graft polymerization of styrene monomer with poly(butyl acrylate) seed, was proposed for the production of a self‐compatibility macromolecule alloy. The effects of the butyl acrylate content, sodium dodecyl sulfate concentration, and polymerization temperature on the graft ratio were investigated. Scanning electron microscopy, transmission electron microscopy, and impact strength were used to characterize the microstructure and mechanical performance of the self‐compatibility macromolecule alloy. The results showed that increasing the butyl acrylate content, reducing the sodium dodecyl sulfate concentration, and improving the polymerization temperature all favored an increased graft ratio, which resulted in increased impact strength of the self‐compatibility macromolecule alloy. Therefore, the concentrated‐emulsion polymerization method is particularly suitable for seed‐graft polymerization. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2915–2920, 2002; DOI 10.1002/app.10288
Bulk modification of styrene–butadiene–styrene triblock copolymer with maleic anhydride
Authors: Wilhelm Helena Maria , Felisberti Maria Isabel
Published: August 2002

The bulk modification of SBS rubber with maleic anhydride in a mixing chamber of a Haake rheomixer was studied. The effect of temperature, maleic anhydride, and benzoyl peroxide concentrations on the grafting efficiency was evaluated. High grafting efficiency was achieved when the ratio of peroxide and maleic anhydride concentration was high. On the other hand, on this condition high insoluble fraction was generated. The addition of a diamine, 4,4′‐diaminediphenylmethane to the reaction mixture minimizes the amount of insoluble polymer. However, the grafted MAH content also decreases. The graft copolymer was characterized by infrared spectroscopy and the grafting extension was determined by titration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2953–2960, 2002; DOI 10.1002/app.10355
Epifluorescence studies and secondary relaxation processes in immiscible blends of polybutadiene‐poly(2‐vinyl naphthalene) by fluorescence spectroscopy
Authors: Cruz M. C. P. , Cassiola F. M. , Atvars T. D. Z.
Published: August 2002

The development of the morphology of polybutadiene/poly(2‐vinyl naphthalene) blends in five proportions by mass (5, 10, 50, 90, and 95%, w/w) is studied by epifluorescence and scanning electron microscopy (SEM) techniques. The phase separation process of these immiscible polymers produces a primary morphology that is formed by dispersed droplets in a continuous matrix. In the sequence a secondary phase separation inside the primary domains is detected by epifluorescence microscopy of the intrinsically fluorescent domains. Secondary phase separation is confirmed by SEM fracture surface analysis. The relative size of the droplets and the matrix composition depend on the proportion of the components of the blends. The mechanism of the phase separation process is preferentially by nucleation growth for either primary or secondary phase separation processes. Secondary relaxation processes involving the poly(2‐vinyl naphthalene) phase are studied by fluorescence spectroscopy. The profile of the steady‐state excimer fluorescence of poly(2‐vinyl naphthalene) with the temperature in the blend differs from that of the isolated homopolymer and is explained by the contribution from the interface to the radiationless deactivation. The Arrhenius plot for the temperature dependence exhibits slope changes that are related to the polymer relaxation processes. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1637–1649, 2002; DOI 10.1002/app.10389
Effect of partitioning of monomer on the reactivities of monomers in microemulsion
Authors: Sanghvi Paresh G. , Pokhriyal Naveen Kumar , Devi Surekha
Published: August 2002

Copolymerization of styrene and 2‐hydroxyethyl methacrylate (2‐HEMA) was carried out in a microemulsion medium. The composition of the copolymers was estimated using proton 1H‐NMR. The reactivity ratios of styrene and 2‐HEMA in ternary microemulsions were observed and were considerable different from those reported for solution and bulk polymerization. In monomer pairs with a considerable difference in polarity, partitioning of a monomer between the aqueous phase and the microemulsion droplets develops a concentration gradient, which can be calculated from the distribution coefficient of the monomer between the two phases. This approach has led to more reliable reactivity ratios for the monomers. The study of styrene–2‐HEMA copolymerization in a sodium dodecylsulfate‐based microemulsion resulted in rS = 3.79 and rH = 0.17 as apparent reactivity ratios and rS = 0.57 and rH = 23.24 as true reactivity ratios for styrene and 2‐HEMA, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1832–1837, 2002; DOI 10.1002/app.10401
Loss and transformation products of the aromatic antioxidants in MDPE film under long‐term exposure to biotic and abiotic conditions
Authors: Haider Nadejzda , Karlsson Sigbritt
Published: August 2002

The loss of a primary phenolic antioxidant Irganox 1010 and of a secondary phosphite antioxidant Irgafos 168 from a medium density polyethylene film (MDPE) was investigated after exposure of the film for 4 years to different environments such as aqueous media at pH5 and 7, open air, and compost, with an exposure of exposition of 25°C. An ultrasonic extraction technique using chloroform as extraction solvent was applied to recover the residual antioxidants from the polymeric matrix, and this was followed by High‐Performance Liquid Chromatography (HPLC) with acetonitrile as mobile phase and a quantitative analysis at a wavelength of 280 nm of the extracted antioxidants. The amount of antioxidant lost varied remarkably depending on the testing medium. The fastest loss of antioxidant was found on exposure to open air and sunlight while the slowest loss was observed in compost. Thermo‐analytical measurements were made to characterize the residual thermo‐oxidative stability of MDPE film in terms of oxidation temperature and oxidation induction time, to provide a greater insight into the underlying mechanisms of ageing in the different environments. Analysis by Gas chromatography–Mass Spectrometry (GC‐MS) revealed that degradation of the polymeric matrix resulted in the formation of hydrocarbons and oxygen‐containing compounds such as alcohols, carboxylic acids, aldehydes, and esters. The transformation products of the antioxidants formed as result of processing or exposure to the tested media were also identified. The transformation of the phenoxy radical of the Irganox 1010 produced the ester, acid, dealkylated cinnamate, and quinone products, whereas Irgafos 168 yielded oxidation products and the phenolic hydrolysis byproduct 2,4‐di‐tert‐butylphenol. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 974–988, 2002
Synthesis and characterization of poly[(R, S)‐3‐hydroxybutyrate] telechelics and their use in the synthesis of poly(methyl methacrylate)‐b‐ poly(3‐hydroxybutyrate) block copolymers
Authors: Arslan Hülya , Hazer Baki̇ , Kowalczuk Marek
Published: August 2002

Poly[(R,S)‐3‐hydroxybutyrate] oligomers containing dihyroxyl (PHB‐diol), dicarboxylic acid (PHB‐diacid) and hydroxyl‐carboxylic acid (a‐PHB) end functionalities were obtained by the anionic polymerization of β‐butyrolacton (β‐BL). Ring opening anionic polymerization of β‐BL was initiated by a complex of 18‐Crown‐6 with γ‐hydroxybutyric acid sodium salts (for PHB‐diol and a‐PHB) or succinic acid disodium salt (for PHB‐diacid). Dihydroxyl functionalization was formed by the termination of polymerization with bromo‐ethanol or bromo‐decanol while the others were done by protonation. Hydroxyl and/or carboxylic acid functionalized PHB oligomers with ceric salts were used to initiate the polymerization of methylmethacrylate (MMA). PHB‐b‐PMMA block copolymers obtained by this way were purified by fractional precipitation and characterized using 1H‐NMR and 13C‐NMR, gel permeation chromatography (GPC), and thermal analysis (DSC and TGA) techniques. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 965–973, 2002
In situ polyurethane/silica composite formation via a sol‐gel process
Authors: Park No‐Hyung , Lee Joon‐Woo , Suh Kyung‐Do
Published: August 2002

Polyurethane acrylate anionomer (PUAA)/silica composite gels were prepared by the sol‐gel reaction of tetraethoxysilane (TEOS) and methacryloxypropyl trimethoxysilane (MPTS) incorporated to PUAA gels by using a swelling method. The formation and structure of composites were confirmed by FTIR, X‐ray diffraction, and SEM. As a result, we found that silica components in composites are located within the ionic domains of their gels and interacted with PUAA via hydrogen bonding. This drastically enhanced the mechanical properties of the composites. Mechanical properties are also improved by MPTS, because MPTS improves the dispersibility and adhesion of silica components in PUAA/silica composite gels. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2327–2334, 2002
Analysis of mixed mode polymerization systems. I. Generalized modeling approach
Authors: Giannakitsas Ioannis , Teymour Fouad
Published: August 2002

Mixed Mode Polymerization (MMP) is introduced and defined as any polymerization process that combines chainwise and stepwise mechanisms, which both contribute to the growth and structure modification of its polymer product. The large difference in activation energies of the growth steps of these two mechanisms provides great flexibility for polymer property control. A large variety of possible combinations including these mechanisms can be designed, which leads to a diversity of processes that require the development of a unified treatment technique. Building on the well‐established theories and modeling frameworks available for free‐radical polymerization and polycondensation, a generalized approach for modeling MMP is developed. Example applications of the technology are discussed and a case study is analyzed to illustrate the applicability of the generalized modeling approach. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 571–594, 2002
[Poly(ethylene terephthalate) ionomer]/silicate hybrid materials via polymer–in situ sol‐gel reactions
Authors: Lambert Alexander A. , Mauritz Kenneth A. , Schiraldi David A.
Published: August 2002

A scheme was developed for producing poly(ethylene terephthalate (PET) ionomer)/silicate hybrid materials via polymer–in situ sol‐gel reactions for tetraethylorthosilicate (TEOS) using different solvents. Scanning electron microscopy/EDAX studies revealed that silicate structures existed deep within PET ionomer films that were melt pressed from silicate‐incorporated resin pellets. 29Si solid‐state NMR spectroscopy revealed considerable Si—O—Si bond formation, but also a significant fraction of SiOH groups. 23Na solid‐state NMR spectra suggested the presence of ionic aggregates within the unfilled PET ionomer, and that these aggregates do not suffer major structural rearrangements by silicate incorporation. For an ionomer treated with TEOS using MeCl2, Na+ ions are less associated with each other than in the unfilled control, suggesting silicate intrusion between PET–SO Na+ ion pair associations. The ionomer treated with TEOS + tetrachloroethane had more poorly formed ionic aggregates, which illustrates the influence of solvent type on ionic aggregation. First‐scan DSC thermograms for the ionomers demonstrate an increase in crystallinity after the incorporation of silicates, but solvent‐induced crystallization also appears to be operative. Second‐scan DSC thermograms also suggest that the addition of silicate particles is not the only factor implicated in recrystallization, and that solvent type is important even in second‐scan behavior. Silicate incorporation does not profoundly affect the second scan Tg vs. solvent type, i.e., chain mobility in the amorphous regions is not severely restricted by silicate incorporation. Recrystallization and melting in these hybrids appears to be due to an interplay between a solvent‐induced crystallization that strongly depends on solvent type and interactions between PET chains and in situ‐grown, sol‐gel‐derived silicate particles. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1749–1761, 2002; DOI 10.1002/app.10586
Synthesis and investigation of the properties of poly(phenyl‐α‐naphthylsilylene)–dimethylsilylene copolymers
Authors: Mukbaniani O. V. , Tatrishvili T. N. , Karchkhadze M. G.
Published: August 2002

A Wurtz‐type reductive coupling reaction of dichlorophenyl‐α‐naphthylsilane was carried out in a mixture of toluene and o‐xylene in the presence of sodium and a catalytic amount of mercury; α,ω‐dichlorophenyl‐α‐naphthylsilylenes of various degrees of polymerization were obtained. Through the hydrolysis of α,ω‐dichlorophenyl‐α‐naphthylsilylenes, corresponding dihydroxy compounds were obtained. The heterofunctional polycondensation of α,ω‐dihydroxyphenyl‐α‐naphthylsilylenes with α,ω‐dichlorodimethylsilylenes was performed both without amines and in the presence of amines. Heterofunctional polycondensation without amines did not proceed with the formation of high molecular weight compounds because the cleavage of both  SiSi and SiOSi bonds took place during condensation. In the presence of amines, polysilylene–silylene copolymers were obtained. The synthesized copolymers were investigated with gel permeation chromatography, differential scanning calorimetry, roentgenography, and thermogravimetry. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1047–1056, 2002
Synthesis and light‐emitting properties of new poly(p‐phenylenevinylene) derivatives containing oxadiazole moiety
Authors: Wang Shu , Hua Wenting , Chen Xiaohong , Hou Yanbing
Published: August 2002

Two new poly(p‐phenylenevinylene) (PPV) derivatives containing oxadiazole moiety (OXA‐PPV1 and OXA‐PPV2) were synthesized by the Wittig condensation polymerization reaction. Their thermal and light‐emitting properties were investigated. The single‐ and triple‐layer electroluminescent (EL) devices with configurations of ITO/polymer/Al and ITO/polymer/OXD‐7/Alq3/Al were fabricated. They exhibited blue emission at 470 nm for OXA‐PPV1 and green emission at 560 nm for OXA‐PPV2. The turn‐on voltages of triple‐layer device were 11 V for OXA‐PPV1 and 8 V for OXA‐PPV2. The triple‐layer EL devices showed much better performance than did the single‐layer devices. The spectra indicated energy transfer occurred from segments of side chain to polymer backbone. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 422–428, 2002
Polytetrahydrofuran amphiphilic networks. III. Synthesis and characterization of pH‐sensitive poly(methacrylic acid)‐l‐polytetrahydrofuran networks
Authors: Guan Ying , Jiang Weiwen , Zhang Wenchuan , Wan Guoxiang , Peng Yuxing
Published: August 2002

A series of pH‐sensitive amphiphilic poly(methacrylic acid)‐l‐polytetrahydrofuran (PMAA‐l‐PTHF) networks were prepared by free radical copolymerization of hydrophobic telechelic polytetrahydrofuran diacrylates (PTHFDA) with hydrophilic methacrylic acid(MAA). Network composition was characterized. The networks are amphiphilic, namely, that swell both in organic solvents and in water. The swelling of the networks in organic solvents or in water is composition dependent. Swelling dynamics of networks indicates a non‐Fickian process in cyclohexane as well as in water. According to swelling experiments, four solubility parameters of PMAA‐l‐PTHF networks were obtained, which correspond to the hydrophilic and hydrophobic segments, and the interaction between these two segments and solvents. The networks are pH sensitive in aqueous media. These results indicate that PMAA‐l‐PTHF networks exhibit not only the properties of PMAA and PTHF segments but also the combined properties of them. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 351–357, 2002
Metal‐solvating and self‐association of amphiphilic polyamides containing poly(oxyethylene) blocks
Authors: Lin J. J. , Cheng I. J.
Published: August 2002

An amphiphilic poly(ether amide) consisting of hydrophilic poly(oxyethylene) amide blocks was prepared from the copolymerization of sebacic acid and two poly(oxyalkylene) diamines including a poly(oxyethylene) diamine (POE‐amine at 2000 Mw) and a poly(oxypropylene) diamine (POP‐amine at 230 Mw). The copolymer was estimated to have an average molecular weight of 15,000 Mw (GPC) or approximately three hydrophilic POE segments per strain. The presence of POE segments rendered polymer hydrophilicity and complexing ability for Li+, K+, Ca+2, Ni+2, Pd+2, and Cu+2 salts. In particular, lithium perchlorate affected the copolymer to the greatest extent in enhancing electrostatic dissipation or reducing surface resistivity as low as 105.0 Ω/sq (cross‐sectional area) at 1/180 Li+/EO from 107.2 Ω/sq (without metal ion). In such a metal complexation, the copolymer showed a new POE segmental crystalline phase at a melting temperature between −10.4 and −14°C, accompanied with the metal‐free original phase of −31°C. In static toluene/water, the metal ions had no effect on the copolymer surfactancy in lowering the interfacial tension, reaching 4.4 dyn/cm at a critical micelle concentration (cmc) of 0.01 wt %. When mixing toluene and water, the lithium or nickel ions were found to be detrimental to the emulsifying process. Without the metal ion, fine droplets at average sizes of 4.5–5.0 μm were observed in the copolymer/ toluene/water emulsification. These amphiphilic behaviors of the POE‐segmented polyamide with or without metal ions were explained by the competing noncovalent bonding interactions among POE/metal ion/water. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 612–621, 2002
In vitro release modulation of hemoglobin from a ternary polymeric delivery vehicle
Authors: Bajpai A. K. , Bhanu Smitha
Published: August 2002

The release of hemoglobin from hydrogel matrices of polyethylene glycol (PEG), polyvinyl alcohol (PVA), and crosslinked polyacrylamide (PAM) was investigated in phosphate‐buffered saline (PBS, pH 7.4) as a release medium. The hemoglobin was loaded onto hyrogels by swelling them in hemoglobin solution and the effect of composition of the hydrogel on the amount of hemoglobin loaded was observed. The effects of experimental parameters such as varying concentrations of PEG, PVA, PAM, and crosslinking agent in the feed mixture, pH of the release medium, and the presence of salts were investigated on the release dynamics of the hemoglobin. The release results were analyzed on the basis of the kinetic data, and the kinetic parameters such as the diffusional exponent (n) and diffusion constant (D) were evaluated. From the kinetic parameters data an attempt was made to explore the nature of the mechanism of the hemoglobin release process. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 104–113, 2002
Thermal decomposition characteristics of poly[diethyl‐2‐(methacryloyloxy)ethyl phosphate] using thermogravimetric analysis/mass spectrometry
Authors: Perng L. H. , Tsai C. J. , Ling Y. C. , Wang S. D. , Hsu C. Y.
Published: August 2002

The thermal decomposition of poly[diethyl 2‐(methacryloyloxy)ethyl phosphate] (PDMP) by free‐radical polymerization was studied by the combination of pyrolysis‐gas chromatography/mass spectrometry (Py‐GC/MS) with thermogravimetric analysis/mass spectrometry (TG/MS), in which the former identified directly the compositions of the evolved gases and the latter could further obtain real‐time evolution curves of pyrolysates. A decomposition of PDMP was a two‐stage process: The dominant mechanism of the first stage was initialized by hydrolysis at the phosphate ester linkage to evolve hydroxyethyl methacrylate (HEMA), triethylphosphate, and ethanol as major products; then, subsequently, the dominant mechanism of the second stage was a main‐chain random scission to form acetaldehyde and water as major products along with carbonization of about 24% char yield of a solid residue at 600°C. Therefore, the reaction of phosphate groups into the backbone of polymeric materials could provide better flame retardancy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 821–830, 2002
Electrochemical copolymerization of aniline and anilinesulfonic acids in FSO3H/acetonitrile solution
Authors: Şahin Yücel , Pekmez Kadir , Yildiz Attila
Published: August 2002

The effects of 2‐aminobenzenesulfonic acid (orthanilic acid), 3‐aminobenzenesulfonic acid (metanilic acid), and 4‐aminobenzenesulfonic acid (sulfanilic acid) on the electropreparation and properties of polyaniline (PANI) were investigated in acetonitrile containing 200 mM fluorosulfonic acid. The cyclic voltammetric studies of the products showed characteristics similar to those of conventional PANI in neutral solution, but there was a significant difference between the electrochemical behavior of the polymer films in basic solution. The sulfur‐to‐nitrogen ratios were found to be about 0.50, which indicated that copolymers were formed. The copolymers were soluble in a basic aqueous solution and in 1‐methyl‐2‐pyrrolidinone and dimethyl sulfoxide solvents. The dry electrical conductivity values of the copolymers were measured. The structure and properties of these conducting copolymers in acetonitrile were elucidated with cyclic voltammetry, Fourier transform infrared spectroscopy, and ultraviolet–visible absorption spectroscopy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1227–1235, 2002
Tensile deformation and fracture mechanism of highly filled high‐density polyethylene/Al(OH)3 composites
Authors: Yang Jinhai , Zhang Yong , Zhang Yinxi
Published: August 2002

The effect of the silicone oil content on the tensile properties and micromechanical deformation of high‐density polyethylene/Al(OH)3 composites was studied. With an increase in the silicone oil content, the elongation at break and notched Izod impact strength of the composites increased, and the local debonding deformation gradually transformed into homogeneous debonding deformation. A model characterizing the micromechanical deformation process was examined. The increase in the silicone oil content decreased the interaction between the filler particles and the high‐density polyethylene matrix and increased the extension speed of the debonded region, which led to the changes in the tensile properties and micromechanical deformation. A good explanation for the tensile properties and micromechanical deformation was obtained through the model. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1207–1218, 2002
Studies on the mesomorphic properties of ferrocenylene‐based organophosphorous liquid‐crystalline polymers containing phenyl and biphenyl pendant units
Authors: Senthil S. , Kannan P.
Published: August 2002

The synthesis, mesomorphic character, and effect of spacers in ferrocene‐containing main‐chain liquid‐crystalline polymers are reported in this article. Two different monomers containing ferrocene and phenyl/biphenyl phosphate groups possessing even numbers of spacers from 2 to 10 were prepared and polymerized by polycondensation at room temperature. All the polymers gave birefringent melt except one. The identification of the mesophase was transparent with an increase in spacers. The effect of substitution in the side chain with regard to bulkiness and spacers were studied with thermogravimetric analysis and differential scanning calorimetry. The results reveal that the thermal stability of the polymers increased with the increasing bulkiness of the side chain and decreased with increasing spacer length. The incorporation of the phosphorous moiety also had a considerable effect on the glass‐transition temperature. Char yield of the polymer decreased with increasing methylene chain length, and it did not vary much with the size of the pendent groups. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 831–841, 2002
Syntheses of an aromatic nitrile ether diamine and the bismaleimide bearing the diamine and the properties of their copolymers with 4,4′‐bismaleimidodiphenylmethane (BMDPM)
Authors: Fang Qiang , Ding Xuemei , Wu Xiongying , Jiang Luxia
Published: August 2002

A new chain‐extension modifier for bismaleimide (BMI), 2,6‐di‐(4‐aminophenoxy)benzonitrile (DAPB), was synthesized through nucleophilic substitution of 2,6‐dichlorobezonitrile by 4‐aminophenol using anhydrous sodium carbonate as an acid acceptor, toluene as a dehydrating agent, and N,N′‐dimethylacetamide (DMAC) as a dipolar aprotic solvent. Based on the diamine, another modifier for bismaleimide, 2,6‐bis(4‐maleimidophenoxy)benzonitrile (BMPB), was also synthesized, first by the reaction of DAPB with maleic anhydride and then by dehydration. DAPB and BMPB were used to modify a popular commercial BMI, 4,4′‐bismaleimidodiphenylmethane (BMDPM), for improving the shear strength of the resin. The results showed that the shear strength of the DAPB‐modified BMDPM resin was superior to that of either neat BMDPM or the 4,4′‐diaminodiphenylmethane (DADPM)‐modified BMDPM (a commercial modified BMDPM resin system). In addition, the heat resistance of the cured DAPB‐modified BMDPM resin was higher than that of the cured DADPM‐modified BMDPM resin. The excellent properties were also found in the BMPB‐modified BMDPM resin. It was found that the BMPB‐modified BMDPM resin was superior to neat BMDPM in both shear strength and heat resistance. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1317–1327, 2002
Viscosity–molecular weight relationship for aminopropyl‐terminated poly(dimethylsiloxane)
Authors: Wu Yongzhong , Feng Shengyu
Published: August 2002

Aminopropyl‐terminated poly(dimethylsiloxane) (ATPS) with different molecular weights was prepared by base‐catalyzed equilibration of octamethylcyclotetrasiloxane and 1,3‐bis(3‐aminopropyl)‐1,1,3,3‐tetramethyldisiloxane with different ratios. Their number‐average molecular weights (Mn) were determined by end–group analysis, and intrinsic viscosity ([η]) in toluene was measured with a Ubbelohde viscometer. A relationship between Mn and [η] was obtained for ATPS. For 1.0 × 104 < Mn < 6.0 × 104, it was in accord with [η]toluene,25°C = 5.26 × 10−2 Mn0.587. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 975–978, 2001
Gas–liquid chromatographic study of polystyrene–n‐alkane interactions
Authors: Naik Huchchuraya G. , Aminabhavi Tejraj M.
Published: August 2002

Gas–liquid chromatography is used to study the thermodynamic interactions between polystyrene and n‐alkanes (C6–C10). Polystyrene is used as a stationary phase with n‐alkanes as the probe molecules. Retention times and specific retention volumes are measured over the temperature interval of 60 to 170°C. Partial molar free energy of mixing, polymer–solvent interaction parameter, glass‐transition temperature, and solubility parameter of polystyrene at infinite dilution are calculated. Experimental results are discussed in terms of the theoretical calculations and size of the probe molecules. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1291–1298, 2001
Synthesis of novel poly(amide‐imide)s containing trimellitylimido‐DL/L‐alanine moieties via direct polycondensation
Authors: Mallakpour Shadpour E. , Hajipour Abdol‐Reza , Habibi Sakineh
Published: August 2002

N‐Trimellitylimido‐DL and L‐alanine (3) were prepared from the reaction of trimellitic anhydride (1) with DL and L‐alanine (2) in N,N‐dimethyl formamide (DMF) solution at refluxing temperature. The direct polycondensation reaction of the monomers imide‐diacid (3) with 4,4′‐diaminodiphenylsulfone (4a), 4,4′‐diaminodiphenylmethane (4b), 1,4‐phenylenediamine (4c), 1,3‐phenylenediamine (4d), 2,4‐diaminotoluene (4e), and 4,4′‐diaminodiphenylether (4f) was carried out in a medium consisting of triphenyl phosphite, N‐methyl‐2‐pyrolidone (NMP), pyridine, and calcium chloride. The resulting poly(amide‐imide)s PAIs, with inherent viscosities 0.32–0.66 dL/g, were obtained in high yield. All of the above‐mentioned compounds were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these new optically active PAIs are reported. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1312–1318, 2001
Syntheses of new amino‐functionalized methacrylates and their use in free radical polymerizations
Authors: Geurts John M. , Göttgens Christianne M. , Van Graefschepe Marco A. I. , Welland Rob W. A. , Steven Van Es J. J. G. , German Anton L.
Published: August 2002

For use in emulsion and solution copolymerization a series of novel amino‐functional methacrylates has been synthesized, most of which have seldom, or never, been described in the literature before. In this investigation, the preparation of the hydrochloric and/or tosylate salt of the monomers aminoethyl, 3‐amino‐1‐propyl, 5‐amino‐1‐pentyl, 6‐amino‐1‐hexyl and 11‐amino‐1‐undecyl methacrylate will be described, along with the characterization of the parameters water solubility, pKa and chemical stability. The homopolymers of these monomers have been prepared and characterized. Results show the occurrence of an acyl migration upon neutralization of the monomers aminoethyl‐ and 3‐amino‐1‐propyl methacrylate. This migration does not occur in the monomer 5‐amino‐1‐pentyl methacrylate, which makes it possible to synthesize the neutralized monomer although, after neutralization, a Michael addition occurs, resulting in a limited lifetime. Copolymerizations have been performed in emulsion. The monomer aminopentyl methacrylate especially proved to be suitable for emulsion copolymerizations when used under controlled conditions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1401–1415, 2001
Studies on high‐speed melt spinning of noncircular cross‐section fibers. II. On‐line measurement of the spin line, including change in cross‐sectional shape
Authors: Takarada Wataru , Ito Hiroshi , Kikutani Takeshi , Okui Norimasa
Published: August 2002

On‐line measurement was performed in the high‐speed spinning of flat, hollow, and circular fibers of poly(ethylene terephthalate), paying particular attention to the change in cross‐sectional shape along the spin line. The diameter profiles of hollow and circular fibers were essentially identical, whereas the deformation of flat fiber shifted to the region closer to the spinneret. The necklike deformation of hollow and circular fibers started at the takeup velocity of 5 km/min. In the case of flat fibers, presence of the necklike deformation was confirmed at 4 km/min, and extremely steep diameter attenuation was observed at 5 km/min. The spin‐line tension of the flat fiber was also larger than that of circular fibers. Combined measurements of fiber velocity and thickness enabled us to evaluate the aspect ratio of the flat fiber and hollow ratio of the hollow fiber in the spin line. These two factors were found to decrease steeply near the spinneret. Accordingly, the thinning of the spin line and the change in cross‐sectional shape appeared to proceed independently. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1582–1588, 2001
Relationship between molecular structure and zero‐shear viscosity of polymers
Authors: Yamamoto Takeshi , Furukawa Hiroaki
Published: August 2002

The relationship between molecular structure and zero‐shear viscosity of polymers was studied. In this study we propose a new equation, which is based on Berry and Fox's equation. This new equation is constructed from some molecular parameters, such as mean square length and average molecular weight of statistical skeletal unit, characteristic ratio, entanglement molecular weight, glass‐transition temperature, free volume fraction at glass‐transition temperature, and thermal expansion coefficient of free volume. It is proposed that some of these molecular parameters could be predicted by group contribution methods, except for the free volume parameters. We also propose new empirical relations between free volume parameters and molecular structures of polymers, which make it possible for free volume parameters to be obtained from molecular structure. Using these relationships, it is possible that the zero‐shear viscosity and its temperature dependence are obtainable from the molecular structure of polymers. We applied this formula to some polymers, including both amorphous and semicrystalline polymers. Comparison between the measured and calculated zero‐shear viscosity showed quite good agreement. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1609–1618, 2001
Study of propylene‐1‐butene‐ethylene terpolymer and reactor blend by TREF and 13C‐NMR
Authors: Filho Adilson Arli Silva , Galland Griselda Barrera
Published: August 2002

A terpolymer of propylene‐1‐butene‐ethylene (TERPO) and a reactor mixture of TERPO with an ethylene‐1‐butene copolymer (BLEND) were completely characterized by TREF, 13C‐NMR, DSC, and GPC, from which special equations for quantitative 13C‐NMR were derived. TERPO was shown to be composed mainly of highly isotactic propene and similar amounts of ethylene and 1‐butene. BLEND fractions were composed of variable amounts of TERPO and a random copolymer of ethylene‐1‐butene. The blend of TERPO and copolymer acts as two independent phases, each having its own elution temperatures dependent only on its crystallizability, itself only influenced by the comonomer content. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1880–1890, 2001
Fluorescence quenching method for measuring monomer consumption rates during free‐radical crosslinking copolymerization
Authors: Pekcan Ö. , Kaya D. , Erdoǧan M.
Published: August 2002

The steady‐state fluorescence (SSF) technique was used to study the polymerization rate in free‐radical crosslinking copolymerization (FCC) of methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDM). Pyrene (Py) was used as a fluorescent probe for the in situ polymerization experiments. The increase in Py intensity was monitored during FCC. The Stern–Volmer kinetic was employed to determine the MMA consumption rate during gelation process for various EGDM contents and at different temperatures. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1907–1913, 2001
Nonaqueous emulsion copolymerization of ethyl methacrylate/lauryl methacrylate in propylene glycol. II. Adsorption of poly(ethylene oxide)–polystyrene–poly(ethylene oxide) triblock copolymer on latex particles
Authors: You Xiaorong , Dimonie Victoria L. , Klein Andrew
Published: August 2002

The adsorption behavior of various poly(ethylene oxide)–polystyrene–poly(ethylene oxide) (PEO‐PS‐PEO) triblock copolymer (TBC) s on acrylic latex particles in propylene glycol was studied. The composition of the PEO‐PS‐PEO triblock polymers varied from 41 to 106 in each PEO block length and from 18 to 41 in the PS block length. The location of the PEO‐PS‐PEO TBC was determined by analyzing for the physically adsorbed amount on the latex surface, the anchored mount on the surface, the entrapped amount inside the particle, and the “free” PEO‐PS‐PEO TBCs in the propylene glycol. A contour graph technique was applied to analyze the experimental data, which showed that a minimum existed for the physically adsorbed portion at a PS block length of about 30 units. When the PS block length was less than 30 units, the adsorption decreased with increasing PS block length, indicating rearrangement of mixed PEO brush and adsorbed PS block. When the PS block was greater than 30 units, the adsorption increased with increasing block length because of the poor solvency of the PS block in the propylene glycol medium, resulting in a collapse of the PS chain. Considering the binding energy between the PS block and the latex particle surface, which governs adsorption, it was hypothesized that a lower block length limit exists, below which no adsorption takes place. The solubility of the PS block in propylene glycol guides the important upper block length limit. The anchored fraction of the block copolymer increased continuously with increasing PS block length in the entire region investigated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1963–1975, 2001
Synthesis and characterization of chiral smectic side‐chain liquid crystalline polysiloxanes and ionomers containing sulfonic acid groups
Authors: Hu Jianshe , Zhang Baoyan , Feng Zhiliu , Wang Hongguang , Zhou Aijuan
Published: August 2002

The synthesis of new chiral smectic A (SA) side‐chain liquid crystalline polysiloxanes (LCPs) and ionomers (LCIs) containing 4‐allyloxy‐benzoyl‐4‐(S‐2‐ethylhexanoyl) p‐benzenediol bisate (ABB) as mesogenic units and 4‐[[4‐(2‐propenyloxy)phenyl]azo]benzenesulfonic acid (AABS) as nonmesogenic units is presented. The chemical structures of the monomers and polymers are confirmed by FTIR spectroscopy or 1H–NMR. Differential scanning calorimetry (DSC), optical polarizing microscopy, and X‐ray diffraction measurements reveal that all the polymers PI–PIV and ionomers PV–PVI exhibit SA texture. The results seem to demonstrate that the tendency toward the SA‐phase region increases with increasing sulfonic acid concentration, and the thermal stability of the SA phase is determined by the flexibility of the polymer backbones and the interactions of sulfonic acid groups. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2335–2340, 2001
Effect of shearing on crystallization behavior of poly(ethylene terephthalate)
Authors: Myung Hee Soo , Yoon Won Jae , Yoo Eui Sang , Kim Byoung Chul , Im Seung Soon
Published: August 2002

The shear‐induced crystallization behavior of PET was investigated by measuring the time‐dependent storage modulus (G′) and dynamic viscosity (η′) with a parallel‐plate rheometer at different temperatures and shear rate. The morphology of shear‐induced crystallized PET was measured by DSC, X‐ray, and polarizing optical microscopy. When a constant shear rate was added to the molten polymer, the shear stress increased with the time as a result of the orientation of molecular chains. The induction time of crystallization is decreased with frequency. Moreover, the rate of isothermal crystallization of PET was notably decreased with increasing temperature. The shape of spherulites is changed to ellipsoid in the direction of shear. In addition, aggregation of spherulites is increased with increasing frequency. Particularly, the row nucleation morphology could be observed under polarized light for ω = 1. From the results of DSC, the melting point and enthalpy have a tendency to decrease slightly with increasing frequency. The crystallite size and perfectness decreased with frequency, which was confirmed with X‐ray data. The unit length of the crystallographic unit cell of the PET increased and the (1 0 3) plane peak increased with increasing frequency. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2640–2646, 2001
Synthesis of poly(ester‐anhydride)s based on poly(ϵ‐caprolactone) prepolymer
Authors: Korhonen Harri , Seppälä Jukka V.
Published: August 2002

The objective of this study was to prepare high molecular weight poly(ester‐anhydride)s by melt polycondensation. The polymerization procedure consisted of the preparation of carboxylic acid terminated poly(ϵ‐caprolactone) prepolymers that were melt polymerized to poly(ϵ‐caprolactone)s containing anhydride functions along the polymer backbone. Poly(ϵ‐caprolactone) prepolymers were prepared using either 1,4‐butanediol or 4‐(hydroxymethyl)benzoic acid as initiators, yielding hydroxyl‐terminated intermediates that were then converted to carboxylic acid‐terminated prepolymers by reaction with succinic anhydride. Prepolymers were then allowed to react with an excess of acetic anhydride, followed by subsequent polycondensation to resulting high molecular weight poly(ester‐anhydride)s. Upon coupling of prepolymers, size exclusion chromatography analyses showed an increase from 3600 to 70,000 g/mol in number‐average molecular weight (Mn) for the 1,4‐butanediol initiated polymer, and an increase from 7200 to 68,000 g/mol for the 4‐(hydroxymethyl)benzoic acid‐initiated polymer. 4‐Hydroxybenzoic acid and adipic acid were also used as initiators in the preparation of poly(ϵ‐caprolactone) prepolymers. However, with these initiators, the results were not satisfactory. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 176–185, 2001
Structural analysis during creep process of ultrahigh‐strength polyethylene fiber
Authors: Ohta Yasuo , Kaji Atsushi , Sugiyama Hiroshige , Yasuda Hiroshi
Published: August 2002

Structural changes during the creep process of ultrahigh‐strength polyethylene fiber (UHSPE) were investigated using X‐ray and the solid‐state NMR techniques. As the creep strain increases, the quantity of the amorphous phase area estimated by the 13C‐NMR method increases until the final creep rupture. On the other hand, the amorphous quantity estimated by the X‐ray method does not change noticeably. To explain this contrast, we proposed a new model that illustrates how the defects such as chain ends incorporated into the crystalline phase are excluded from the crystallite and agglomerate to generate a new amorphous area, which has a size hardly detected by the X‐ray method. These small amorphous areas are considered to cause a decrease in the tensile strength and the successive final creep rupture. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 312–320, 2001
Thermal interaction between polymer‐based composite friction materials and counterfaces
Authors: Abbasi F. , Shojaei A. , Katbab A. A.
Published: August 2002

Attempts have been made to improve the performance of polymeric composite friction materials for eliminating undesirable mechanical and thermal effects on the opposing surfaces. Elastic compression modulus and thermal conductivity of the moulded friction materials were found to be the most effective parameters upon the thermal interaction between the disc and brake pad. Effects of elastic modulus on temperature accumulation of the interface have also been studied. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 364–369, 2001
Phase separation and crystallization behavior in extruded polypropylene/ethylene–propylene rubber blends
Authors: Lee Jong Kwan , Lee Joo Hyung , Lee Kwang Hee , Jin Byung Suk
Published: August 2002

Liquid–liquid (L–L) phase separation and its effects on crystallization in polypropylene (PP)/ethylene–propylene rubber (EPR) blends obtained by melt extrusion were investigated by time‐resolved light scattering (TRLS) and optical microscopy. L–L phase separation via spinodal decomposition (SD) was confirmed by TRLS data. After L–L phase separation at 250°C for various durations, blend samples were subjected to a temperature drop to 130°C for isothermal crystallization, and the effects of L–L phase separation on crystallization were investigated. Memory of the L–L phase separation via SD remained for crystallization. The crystallization rate decreased with increasing L–L phase‐separated time at 250°C. Slow crystallization for the long L–L phase‐separated time could be ascribed to decreasing chain mobility of PP with a decrease in the EPR component in the PP‐rich region. The propylene‐rich EPR exhibited good affinity with PP, leading to a slow growth of a concentration fluctuation during annealing. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 695–700, 2001