bluuebunny/crossref_metadata_2025 huggingface dataset:
Rheological behavior of polyester blend and mechanical properties of the polypropylene–polyester blend fibers
Authors: Marcinčin Anton , Körmendy Eva , Hricová Marcela , Rusnák Andrej , Aneja Arun Pal
Published: September 2006

The article deals with method of preparation, rheological properties, phase structure, and morphology of binary blend of poly(ethylene terephthalate) (PET)/poly(butylene terephthalate) (PBT) and ternary blends of polypropylene (PP)/(PET/PBT). The ternary blend of PET/PBT (PES) containing 30 wt % of PP is used as a final polymer additive (FPA) for blending with PP and subsequent spinning. In addition commercial montane (polyester) wax Licowax E (LiE) was used as a compatibilizer for spinning process enhancement. The PP/PES blend fibers containing 8 wt % of polyester as dispersed phase were prepared in a two‐step procedure: preparation of FPA using laboratory twin‐screw extruder and spinning of the PP/PES blend fibers after blending PP and FPA, using a laboratory spinning equipment. DSC analysis was used for investigation of the phase structure of the PES components and selected blends. Finally, the mechanical properties of the blend fibers were analyzed. It has been found that viscosity of the PET/PBT blends is strongly influenced by the presence of the major component. In addition, the major component suppresses crystallinity of the minor component phase up to a concentration of 30 wt %. PBT as major component in dispersed PES phase increases viscosity of the PET/PBT blend melts and increases the tensile strength of the PP/PES blend fibers. The impact of the compatibilizer on the uniformity of phase dispersion of PP/PES blend fibers was demonstrated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4222–4227, 2006
Study of viscosity abnormality of PS/toluene solution in extremely dilute concentration regime
Authors: Du Deng‐Xue , Zuo Ju , An Ying‐Li , Zhou Lei , Liu Yun
Published: September 2006

The concentration dependence of the reduced viscosity ηsp/c and the translational diffusion coefficient D as well as the radius of gyration Rg of polystyrene in toluene were studied by viscometry and laser light scattering (LLS), respectively. The influence of the experimental error on the determination of the ηsp/c was investigated and a quantitative relation was given out. Viscometric experiment found that the ηsp/c–c curve is clearly divided into two parts by dynamic contact concentration cs. When c > cs, it shows normal linearity as predicted by Huggins equation. But when c < cs, i.e., in the extremely dilute regime, the ηsp/c–c curve is no longer linear and levels off considering the experimental uncertainty. This new finding was confirmed by the following LLS experiment, which indicates that the size of the polymer chains no longer varies with concentration when c < cs. As a result, we, for the first time, using the method of combination of viscometry and LLS, prove an important conclusion that in the extremely dilute concentration regime, the reduced viscosity of polymer solution, at least for PS/toluene, conforming to the Einstein viscosity equation is just the intrinsic viscosity and independent of the concentration. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4440–4446, 2006
Copolymers of acrylic acid with 2‐acryloyloxyethyl 2,4‐dichlorophenoxyacetate: Synthesis and herbicide release
Authors: Fernández‐García Marta , Sánchez‐Chaves Manuel
Published: September 2006

Free‐radical copolymerization of acrylic acid with 2‐acryloyloxyethyl 2,4‐dichlorophenoxyacetate using 1.0 mol/L 1,4‐dioxane solution and 1.5 × 10−2 mol/L of 2,2′ azobisisobutyronitrile as initiator has been carried out at 50°C. In addition to low conversion solution experiments performed to estimate the monomer reactivity ratios, three different copolymerizations over the whole range of conversions have been made. Theoretical values of cumulative copolymer composition, determined by the Mayo‐Lewis terminal model, have been correlated with those experimentally obtained. Finally, the herbicide release in three different aqueous pH buffer solutions has been evaluated in heterogeneous phase. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4238–4244, 2006
Effects of multiple weak interactions on the binding of phenolic compounds by polymeric adsorbents
Authors: Cheng Shaoling , Tang Haiyan , Yan Husheng
Published: September 2006

To investigate the effects of multiple weak interactions on the binding of phenolic compounds by polymeric adsorbents, macroporous polystyrene (PS) resin and PS‐based adsorbents with different hydrogen‐bond acceptor atoms (PSCH2(OCH2CH2)nOCH3, n = 0, 1, 2, and 3, denoted as PS‐EG0, PS‐EG1, PS‐EG2, and PS‐EG3) were prepared. The phenol adsorption strength order on these adsorbents was PS/PS‐EG0 < PS‐EG1 < PS‐EG2 < PS‐EG3, indicating that the adsorption on PS and PS‐EG0 was driven by hydrophobic and π–π interactions, and the adsorption on PS‐EG1, PS‐EG2, and PS‐EG3 was driven by a hydrogen bond in addition to hydrophobic and π–π interactions. PS‐EG2 may adsorb a second phenol molecule on each binding site and PS‐EG3 may adsorb second and third ones. The adsorption strength of resorcinol increased in the order of PS, PS‐EG1, and PS‐EG2, indicating that the adsorption was driven by 0, 1, and 2 hydrogen bonds in addition to hydrophobic and π–π interactions. Similarly, the adsorption of phloroglucinol on PS, PS‐EG1, PS‐EG2, and PS‐EG3 was driven by 0, 1, 2, and 3 hydrogen bonds in addition to hydrophobic and π–π interactions because the adsorption strength increased in this order. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4652–4658, 2006
Control of coefficient of thermal expansion in elastomers using boron nitride
Authors: Iyer Subramanian , Detwiler Andrew , Patel Sanjay , Schiraldi David A.
Published: September 2006

The thermal expansion properties of three commercial elastomers; Pebax®, Estane® and Hytrel® modified with 2.5–10 wt % boron nitride were investigated. The glass transition temperatures of the filled materials were relatively unaffected; however boron nitride did effectively reinforce all the three elastomers as seen by dynamic mechanical analysis and tensile tests. The coefficients of thermal expansion of the composite materials do not obey the rule of mixtures and show a large decrease without the loss of ductility typically associated with filled elastomers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5153–5161, 2006
Effects of the molecular structure of impact modifier and compatibilizer on the toughening of PBT/SBS/PS‐GMA blends
Authors: Canto L. B. , Hage E. , Pessan L. A.
Published: September 2006

This work aims at studying the toughening process of poly(butylene terephthalate) (PBT) through its blends with styrene‐butadiene‐styrene block copolymers (SBS), in the presence of poly(styrene‐ran‐glicydil methacrylate) (PS‐GMA) as reactive compatibilizer. High values of impact strength were attained for PBT/SBS blends without the compatibilizer; however, this improvement is achieved for blends with SBS having similar viscosity compared to PBT, at high SBS content (40 wt %) and for blends prepared under specific processing conditions. The efficiency of the in situ compatibilization of PBT/SBS blends by PS‐GMA was found to be strongly dependent on the SBS and PS‐GMA molecular characteristics. Better compatibilizing results were observed through fine phase morphologies and lower ductile to brittle transition temperatures (DBTT) as the interfacial interaction and stability of the in situ formed compatibilizer are maximized, that is, when the miscibility between SBS and PS‐GMA and reaction degree between PBT and PS‐GMA are maximized. For the PBT/SBS/PS‐GMA blends under study, this was found when it is used the SBS with higher polystyrene content (38 wt %) and with longer PS blocks (Mw = 20,000 g mol−1) and also the PS‐GMA with moderate GMA contents (4 wt %) and with molecular weight similar to the critical one for PS entanglements (Mc = 35,000 g mol−1). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5795–5807, 2006
Production and characterization of natural fiber‐reinforced thermoplastic composites using wheat straw modified with the fungus Pleurotus ostreatus
Authors: Schirp Anke , Loge Frank , Aust Steven , Swaner Paul , Turner Glenn , Wolcott Michael
Published: September 2006

Wheat straw is an abundantly available and potentially valuable biomass that is currently under‐exploited. In this study, the feasibility of using wheat straw as a filler in high‐density polyethylene (HDPE)‐based composites was explored. Straw was treated with the white‐rot fungus Pleurotus ostreatus with the aim of improving adhesion between straw and plastic, and thereby the mechanical properties of the composite. Results indicate that the use of sterilized straw is necessary to inhibit the growth of indigenous organisms that preclude, likely through competition, removal of lignin, and hence, improved bonding between straw and plastic. Light and transmission electron microscopy revealed cell wall modification in sterilized, inoculated straw. Reduced thermal stability of treated straw did not negatively affect the production of injection‐molded straw–plastic composites (SPC). Comparable interfacial adhesion, based on activation energies obtained in dynamic mechanical analysis, was observed in untreated and treated straw‐ and pine‐based thermoplastic composites. The results of this study indicate that wheat straw represents a promising alternative to wood fillers in the production of thermoplastic composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5191–5201, 2006
Free‐radical copolymerization kinetics of acrylonitrile and methyl acrylate in [BMIM]BF4
Authors: Li Da , Zhang Yumei , Wang Huaping , Tang Jianzhong , Wang Biao
Published: September 2006

The copolymerization of acrylonitrile (AN) and methyl acrylate (MA) was carried out in ionic liquid [BMIM]BF4 in the presence of azobisisobutyronitrile (AIBN) as an initiator to investigate the polymerization kinetic, including the copolymerization rate, reactivity ratios, and activation energy. The copolymerization rate equation was established according to the effect of initiator and monomer concentrations on the conversion. The copolymerization rate Rp can be noted as $R_p = {\rm KC}_{\rm AIBN} {^{0.74}} C_{\rm MA} {^{0.61}} C_{\rm AN} {^{0.44}}$, when the copolymerization was in the steady state. The apparent activation energy is 87.94 kJ/mol, while the value of that in the conventional organic solvent (DMF) is ∼ 81 kJ/mol. The reactivity ratios of the investigate system are rAN = 0.36 and rMA = 0.68. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4254–4257, 2006
Preparation of high‐molecular‐weight poly(vinyl alcohol) with high yield by solution polymerization of vinyl acetate in methanol using 4,4′‐azobis(4‐cyanovaleric acid)
Authors: Lyoo Won S. , Song Du H. , Lee Won C. , Han Sung S. , Noh Seok K.
Published: September 2006

Vinyl acetate (VAc) was solution‐polymerized at 40°C and 50°C using 4,4′‐azobis(4‐cyanovaleric acid) (ACVA) as an initiator and methanol as a solvent, and effects of polymerization temperature and initiator concentration were investigated in terms of conversion of VAc into poly (vinyl acetate) (PVAc), degree of branching (DB) for acetyl group of PVAc, and molecular weights of PVAc and resulting poly(vinyl alcohol) (PVA) obtained by saponifying with sodium hydroxide. Slower polymerization rate by adopting ACVA and lower viscosity by methanol proved to be efficient in obtaining linear high‐molecular‐weight (HMW) PVAc with high conversion and HMW PVA. PVA having maximum number–average degree of polymerization (Pn) of 4300 could be prepared by the saponification of PVAc having maximum Pn of 7900 polymerized using ACVA concentration of 2 × 10−5 mol/mol of VAc at 40°C. Moreover, low DB of below 1 could be obtained in ACVA system, nevertheless of general polymerization temperatures of 40°C and 50°C. This suggests an easy way for producing HMW PVA with high yield by conventional solution polymerization without using special methods such as low‐temperature cooling or irradiation. © 2006 Wiley Periodicals, Inc. J Appl PolymSci 102: 4831–4834, 2006
X‐ray photoelectron, infrared, and Raman spectroscopy studies of novel submicrometric poly[(methacrylato)aluminum(III)]
Authors: Vilchis‐Nestor Alfredo R. , Sánchez‐Mendieta Victor , Ureña‐Nuñez Fernando , López‐Castañares Rafael , Ascencio Jorge A.
Published: September 2006

Poly[(methacrylato)aluminum(III)] was prepared by applying γ‐radiation to the corresponding aluminum(III) methacrylate monomer. Scanning electron microscopy images show pellets of ∼ 500 nm for the aluminum(III) methacrylate monomer, and submicrometric fibers‐made granules for the aluminum‐containing polymers. X‐ray photoelectron spectroscopy measurements reveal two peaks in the Al 2p core‐level spectra of the monomer and of the poly[(methacrylato)aluminum(III)], which means that two different coordination modes for the Al(III) ions might be present in these compounds. Infrared and Raman spectroscopy studies confirmed that the structure for this novel coordination polymer consists of hexa‐coordinated Al(III) ions linked by the carboxylate groups of methacrylate ligands, along with hydroxyl groups and coordinated water, in a combination of monodentate and bridging bidentate coordination modes. Hence, combination of spectroscopic methods is a helpful tool to get valuable information on the structure of nonmacrocrystalline coordination polymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5212–5223, 2006
Effect of microphase‐separation promoters on the shape‐memory behavior of polyurethane
Authors: Chen Shaojun , Cao Qi , Jing Bo , Cai Yuanli , Liu Pengsheng , Hu Jinlian
Published: September 2006

A series of segmented polyurethanes (PUs) with novel thermosensitive shape‐memory behavior were synthesized via the in situ addition of a small amount of 1‐octadecanol (ODO) to a PU system. For comparison, liquid paraffin (LP) modified PUs were also synthesized. The effects of a small amount of ODO or LP on the PU suprastructure and the thermosensitive shape‐memory properties were studied with X‐ray diffraction, differential scanning calorimetry, dynamic mechanical analysis, and shape‐memory studies. The results indicated that the in situ addition of a small amount of ODO (e.g., 0.3 wt %) remarkably promoted microphase separation, facilitating the ordered packing of soft segments and the formation of perfect hard‐segment domains and thus significantly improving the shape‐memory properties. In contrast, LP had less significant influence on the shape‐memory behavior because of the macrophase separation of these nonpolar alkyl chains from the PU system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5224–5231, 2006
Preparation and characterization of biodegradable foams from calcium carbonate reinforced poly(propylene carbonate) composites
Authors: Jiao J. , Xiao M. , Shu D. , Li L. , Meng Y. Z.
Published: September 2006

Biodegradable foams were successfully prepared from calcium carbonate reinforced poly(propylene carbonate) (PPC/CaCO3) composites using chemical foaming agents. The incorporation of inexpensive CaCO3 into PPC provided a practical way to produce completely biodegradable and cost‐competitive composite foams with densities ranging from 0.05 to 0.93 g/cm3. The effects of foaming temperature, foaming time and CaCO3 content on the fraction void, cell structure and compression property of the composite foams were investigated. We found that the fraction void was strongly dependent on the foaming conditions. Morphological examination of PPC/CaCO3 composite foams revealed that the average cell size increased with increasing both the foaming temperature and the foaming time, whereas the cell density decreased with these increases. Nevertheless, the CaCO3 content showed opposite changing tendency for the average cell size and the cell density because of the heterogeneous nucleation. Finally the introduction of CaCO3 enhanced the compressive strength of the composite foams dramatically, which was associated with well‐developed cell morphology. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5240–5247, 2006
Mechanical and morphological properties of recycled high‐density polyethylene, filled with calcium carbonate and fly ash
Authors: Atikler U. , Basalp D. , Tihminlioğlu F.
Published: September 2006

In this study, mechanical and morphological properties of composites made up of recycled high‐density polyethylene (HDPE) filled with calcium carbonate and fly ash (FA) were studied. Interfacial interactions were modified to improve the filler compatibility and mechanical properties of the composites by surface treatment of the FA filler with 3‐amino propyl triethoxy silane. The composites were prepared by using a Thermo Haake Rheomixer. Effect of filler loading and treatment of FA with silane coupling agent on mechanical and morphological properties were investigated and it was found that silane treatment indicated significant improvements on the mechanical properties of the HDPE‐FA composites. The improvement with silane treatment of FA was also confirmed by applying the Pukanszky model. Scanning electron microscopy on the fracture surface of composites had given direct evidence of better interfacial adhesion via silane treatment. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4460–4467, 2006
Grafting of N‐carbamyl maleamic acid onto a styrene–butadiene–styrene copolymer
Authors: Lassalle V. L. , Failla M. D. , Vallés E. M.
Published: September 2006

A styrene–butadiene–styrene block copolymer (SBS) was functionalized with N‐carbamyl maleamic acid (NCMA) using two peroxide initiators with the aim of grafting polar groups onto the molecular chains of the polymer. The influence of the concentration of benzoyl peroxide (BPO) and 2,5‐dimethyl, 2,5‐diterbuthylperoxihexane (DBPH) was studied. The concentration of peroxy groups ranged between 0.75 and 6 × 10−4 mol % while the concentration of NCMA was constant at 1 wt %. The reaction temperature was chosen according to the type of peroxide employed, being 140°C for BPO and 190°C for DBPH. FTIR spectra confirmed that NCMA was grafted onto the SBS macromolecules. It was found that the highest grafting level was achieved at a concentration of peroxy groups of about 3 × 10−4 mol %. Contact angle measurements were used to characterize the surface of the SBS and modified polymers. The contact angle of water drops decreased with the amount of NCMA grafted from 95°, the one corresponding to the SBS, to about 73°. T‐peel strength of polymer/polyurethane adhesive/polymer joints made with the modified polymers was larger than those prepared with the original SBS. The peel strength of SBS modified with 1.5 and 3 × 10−4 mol % of peroxy groups from BPO were five times larger than that of the original SBS. The materials modified using BPO showed peel strengths higher than the ones obtained with DBPH. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4468–4477, 2006
Structure of P(VDF‐TrFE) (80/20) copolymers under electron irradiation and recrystallization
Authors: Li Weiping , Jiang Limin , Zhu Yuejin , Wang Jun
Published: September 2006

The structural changes of irradiated and recrystallized copolymers of vinylidene fluoride and trifluoroethylene [P(VDF‐TrFE)] (80/20) copolymers have been investigated through IR spectra, X‐ray, and DSC. It is found that recrystallization has a reverse effect on irradiated P(VDF‐TrFE) copolymers, by which the irradiated samples are turned back to original nonirradiated state partially. During recrystallization, trans‐gauche sequences are replaced by all‐trans conformation gradually and the irradiated P(VDF‐TrFE) (80/20) copolymers change from nonpolar phase to polar one. The average crystallite size of polar phase is larger than that in irradiated samples, and the difference between recrystallized and irradiated samples reduces gradually with irradiation dosage. The CC and conjugated CC bonds are also found in the recrystallized‐irradiated P(VDF‐TrFE) (80/20) due to rearrangement of broken bonds. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4258–4263, 2006
Influence of 1,2‐unit contents on retraction behaviors of SBR vulcanizates
Authors: Choi Sung‐Seen , Cho Gyunggoo
Published: September 2006

Styrene‐butadiene rubber (SBR) has four different repeat units of styrene, cis‐1,4‐, trans‐1,4‐, and 1,2‐uints. Influence of the 1,2‐unit content on the retraction behaviors of SBR vulcanizates reinforced with silica or carbon black was studied. The retraction behaviors were compared in terms of the filler systems and the microstructures of SBR. The silica‐filled vulcanizates containing a coupling agent showed nearly the same retraction behaviors as the carbon black‐filled ones, but the silica‐filled vulcanizates without a coupling agent were recovered slower than the carbon black‐filled ones. The vulcanizates with lower 1,2‐unit content started to recover at lower temperature than that with higher 1,2‐unit content. The recovery rate increased with increase of the 1,2‐unit content of SBR. The experimental results were explained with the polymer‐filler interactions, filler dispersion, glass transition temperature, and modulus. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4707–4711, 2006
A constitutive law for poly(butylene terephthalate) nanofibers mats
Authors: De Vita R. , Leo D. J. , Woo K. D. , Nah C.
Published: September 2006

A three‐dimensional structural constitutive equation is proposed to describe the mechanical properties of poly(butylene terephthalate) nanofibers mats. The model is formulated under the assumption that the mechanical response of the fibrous mat is determined by the individual fibers. The inelasticity, which has been observed when subjecting the fibrous mat to tensile tests, is assumed to be due to the gradual breakage of linear elastic fibers. The constitutive relation also takes the material anisotropy associated with the fibers' architecture into account. Uniaxial experimental data were used to assess the proposed model. The results demonstrate that the model is well suited to reproduce the typical tensile behavior of the fibrous mat. In agreement with the empirical observations, the model predicts that almost all the fibers fail when the poly(butylene terephthalate) fibrous mat sample breaks. Nevertheless, multiaxial stress–strain data and quantification of the fibers' orientation are required to completely validate the constitutive law. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5280–5283, 2006
Characterization of (PEO)LiClO4‐Li1.3Al0.3Ti1.7(PO4)3 composite polymer electrolytes with different molecular weights of PEO
Authors: Wang Yan‐Jie , Pan Yi , Wang Li , Pang Ming‐Jie , Chen Linshen
Published: September 2006

A group of polyethylene oxide (PEO)LiClO4‐Li1.3Al0.3Ti1.7(PO4)3 composite polymer electrolyte (CPE) films was prepared by the solution‐cast method. In each film, EO/Li = 8 and the Li1.3Al0.3Ti1.7(PO4)3 content of 15 wt % were fixed, but the number averaged molecular weight of PEO (Mn) was altered from 5 to 7 × 104 to 106, 2.2–2.7 × 106, 3–4 × 106, 4–5 × 106, and 5.5–6 × 106, respectively. Several techniques including X‐ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and electrical impedance spectroscopy (EIS) were used to characterize the CPE films. LiClO4 was found to have a strong tendency to complex with PEO, but Li1.3Al0.3Ti1.7(PO4)3 was rather dispersed in PEO matrix. DSC analysis revealed that the amorphous phase was dominant in the CPE films although the PEOs before‐use was considerably crystalline. SEM study showed smooth and homogeneous morphologies of the films with low molecular weight PEO and a dual phase characteristic for those with high molecular weight PEO. EIS results indicated that the CPE films are all ionic conductor and the conducting behavior obeys Vogel‐Tamman‐Fulcher (VTF) equation. The parameters in VTF equation were obtained and discussed by taking into considerations PEO molecular weights and crystallinities of the CPE films. Of all the films, the one with PEO with the smallest Mn = 5–7 × 104 had the maximum conductivity, i.e., 1.590 × 10−5 S cm−1 at room temperature and 1.886 × 10−3 S cm−1 at 373 K. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4269–4275, 2006
Surface hydrolysis of postconsumer polyethylene terephthalate to produce adsorbents for cationic contaminants
Authors: Rosmaninho Marcelo G. , Jardim Erika , Moura Flávia C. C. , Ferreira Gilmara L. , Thom Viviani , Yoshida Maria I. , Araujo Maria H. , Lago Rochel M.
Published: September 2006

In this work, the surface hydrolysis of postconsumer polyethylene terephthalate (PET) was used to produce an ion exchange material to adsorb cationic contaminants from water. The PET surface hydrolyses were carried out in neutral, alkaline, and acid media (NaOH or HNO3 at 7, 10, and 15 mol L−1) under reflux producing surface carboxylic acid sites (COOH) characterized by ATR‐IR, pyridine adsorption, titration, TG, and DSC analyses. Acid hydrolysis produced high concentrations of COOH (up to 0.5 mmol g−1PET), whereas no significant concentration of carboxylic acid sites was obtained by neutral and alkaline hydrolysis. SEM analyses suggest that the acid sites are likely located at the cracks and defects produced on the PET surface by acid hydrolysis. Neutral or alkaline hydrolysis produced a very regular and smooth PET surface with very low acid site concentrations. The adsorption isotherms of Cd+2 as a model of heavy metal and the dye methylene blue as a model of large organic cationic molecules showed high adsorption capacities for the HNO3‐hydrolyzed PET, whereas no adsorption takes place on the neutral‐ or alkaline‐hydrolyzed polymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5284–5291, 2006
Dynamic mechanical and rheological behavior of fluoroelastomer‐organoclay nanocomposites obtained from different preparation methods
Authors: Valsecchi R. , Viganò M. , Levi M. , Turri S.
Published: September 2006

A comparison among different preparation methods of fluoropolymer/clay nanocomposites based on a fluoroelastomeric matrix (Tecnoflon® P959) and organomodified montmorillonite clay (Cloisite®20A) is reported. While melt blending leads to intercalated structures, the X‐ray diffraction patterns of solution blended nanocomposite suggest a better delamination of the clay platelets within the fluoropolymeric matrix (no diffraction peaks) if the solvent evaporation step is carried out very slowly (72 h) at ambient pressure and moderate temperature. For the solution blended‐slow evaporation nanocomposite, dynamic mechanical analysis and dynamic rheological measurements show a strong increase in G′, a lower damping peak at Tg, and a pseudosolid like behavior in the terminal flow region, suggesting a likely exfoliation of the organomodified clay in the fluoroelastomeric matrix. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4484–4487, 2006
Polymerization of monomers initiated by silyl centers in SiO deposits prepared by pulsed laser ablation
Authors: Dřínek Vladislav , Vacek Karel , Yuzhakov Gleb , Brus Jiří
Published: September 2006

Deposits from silicon monoxide prepared by pulsed laser ablation were allowed to react with acrylic and vinyl monomers—styrene, methyl methacrylate and 1,2 ethylene glycol dimethacrylate. It was revealed by means of FTIR, electron paramagnetic resonance (EPR), and NMR spectroscopies that silyl Si· reacts with monomer molecules and initiates the consecutive polymerization. Crosslinking is proved by the occurrence of bending δ(CH2) absorption peak at about 750 cm−1 in FTIR spectra. Because of very low concentration of the propagating radical for styrene we used a radical scavenger N‐phenyl‐t‐butylnitrone for trapping. The measured EPR parameters were compared with the calculated ones. In case of styrene, NMR analysis manifested the presence of SiC bonds in SiCxOy (x + y = 2) units, which can be taken as direct evidence of the reaction between silyl centers and monomer molecules. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4488–4492, 2006
Effect of partial replacement of di(2‐ethyl hexyl)phthalate, by a polymeric plasticizer, on the permeability and leaching properties of poly(vinyl chloride)
Authors: Sunny M. C. , Ramesh P. , George K. E.
Published: September 2006

Acrylonitrile butadiene rubber (NBR) was used as a polymeric plasticizer in poly(vinyl chloride) (PVC) for the partial replacement of di(2‐ethyl hexyl)phthalate (DEHP). The effect of this partial replacement on DEHP leaching from the PVC was evaluated at 10, 25, and 40°C. The study shows that the incorporation of NBR reduces the rate of DEHP leaching, the reduction being prominent at lower temperatures. Gas permeability of the NBR‐modified samples was also evaluated at the above temperatures using oxygen and carbon dioxide. A reduction in gas permeability is observed in NBR‐modified samples compared to the PVC plasticized with DEHP alone particularly in the case of carbon dioxide. Water vapor transmission rates of the NBR‐modified samples are higher than that of the control sample. The NBR‐modified PVC sample was found to be noncytotoxic in the in vitro cytotoxic evaluation both by direct contact and test on extract methods. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:4720–4727, 2006
Effect of Quasi‐nanometer zirconium carbide on the physical characterization of zirconium carbide/polyurethane composite films irradiated under ultraviolet light
Authors: Tasi Hui‐An , Suen Maw‐Cherng , Chen Cheng‐Chi
Published: September 2006

We used quasi‐nanometer zirconium carbide (ZrC) and a polyurethane (PU) resin under roller pressure to form a composite film and found that the tensile strength at break, elongation at break, and modulus gradually decreased with increasing ultraviolet (UV)‐irradiation time for films of both PU and the PU/ZrC composite. However, this phenomenon was significantly higher for the PU film than for the ZrC/PU composite film. The construction of the PU film changed after UV irradiation, but that of the PU/ZrC composite film was almost unchanged. The degradation of PU molecules occurred in the absence of ZrC particles after irradiation with UV light but almost did not occur in the presence of ZrC particles. This was confirmed with Fourier transform infrared spectroscopy and gel permeation chromatography analyses. It was suggested that polymer radicals which formed through the photooxidation of UV irradiation and free radicals which formed through the photoreduction of nanometer ZrC/UV irradiation interacted to form a dead polymer to stop the degradation; simultaneously, the chemical bonding between polymer molecules could be re‐formed from free radicals created by photooxidation and photoreduction and thus reduce the mobility of PU molecules, thereby raising the glass‐transition and melting temperatures of the soft segment. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4842–4849, 2006
Retention of activity of urease immobilized on grafted polymer films
Authors: Yamada Kazunori , Iizawa Yoshinori , Yamada Jun‐ichi , Hirata Mitsuo
Published: September 2006

Expanded poly(tetrafluoroethylene) (ePTFE) films grafted with 2‐hydroxyethyl methacrylate (HEMA) and 2‐hydroxyethyl acrylate (HEA) were applied to a polymer support for urease immobilization. The HEMA‐ and HEA‐grafted ePTFE (ePTFE‐g‐PHEMA and ePTFE‐g‐PHEA) films prepared by the combined use of the plasma treatment and photografting possessed high water‐absorptivities. Imidazole groups were introduced to grafted PHEMA and PHEA chains with 1,1′‐carbonyldiimidazole (CDI) in acetonitrile. The activity of urease covalently immobilized to the ePTFE‐g‐PHEMA and ePTFE‐g‐PHEA films in a pH 7.0 buffer at 4°C had the maximum value at the optimum pH value of 7.5 for native urease. Urease immobilized on the ePTFE‐g‐PHEMA films with the extent of CDI bonding of about 20% had the maximum activity, and the repeatedly measured activity was kept almost constant. The relative activity of immobilized urease stayed almost constant in the range of the immobilized amounts between 10 and 30 mg/g for both grafted ePTFE films, and decreased at higher immobilized amounts because of the crowding of immobilized urease molecules in the grafted layers. The relative activity of immobilized urease had the maximum values at the grafted amounts of 1.2 and 1.7 mmol/g for the ePTFE‐g‐PHEMA and ePTFE‐g‐PHEA films, respectively, and the further increase in the grafted amount resulted in the decrease in the relative activity. The optimum temperature of the activity for immobilized urease was shifted from 30 to 50°C for native urease by the covalent immobilization on both grafted ePTFE films and immobilized urease was repeatedly usable without a considerable decrease in the activity in the regions of the pH 6.0–9.0 and 10–60°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4886–4896, 2006
Synthesis and characterization of hydrophilic nanocomposite coating on glass substrate
Authors: Rahimi Azam , Gharazi Salimeh , Ershad‐Langroudi Amir , Ghasemi Diba
Published: September 2006

Hydrophilic coatings based on 3‐glicidoxy propyl trimethoxy silane (GPTMS) and polyethylene glycol (PEG) were prepared with the incorporation of tetramethoxysilane (TMOS) and silica nanoparticle colloidal suspension by a sol–gel process. Characterization of the coatings has been performed by Fourier Transform Infrared (FTIR) and Attenuated Total Reflectance Infrared (ATR‐IR) techniques. Morphological properties were characterized by Scanning Electron Microscopy (SEM). The distribution of Si atoms in the hybrid system was obtained by Si mapping. The particle size in sol solution of the coating was measured by light scattering analyzer. Optical properties were characterized by using UV–vis spectrophotometer. The hydrophilicity of the coating was determined by contact angle measurements, and also the results have been confirmed by surface energy and water uptake investigations. The obtained results indicate that the surfactants affected the contact angles remarkably but did not change the transparency. It has been found that applying silica nano particles leads to coatings with different properties than those using TMOS, while siloxane contents were the same in these two set of coatings. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5322–5329, 2006
Determination of the relative importance of process factors on particle size distribution in suspension polymerization using a Bayesian experimental design technique
Authors: Vivaldo‐Lima Eduardo , Penlidis Alexander , Wood Philip E. , Hamielec Archie E.
Published: September 2006

The use of a Bayesian experimental design technique to determine the relative importance of factors that control particle size distribution (PSD) in suspension copolymerization of styrene and divinylbenzene is reported. Six factors and two responses are considered in this study. The experimental trials are of the two‐level factorial type designed with a Bayesian method. The experiments were carried out in a 5‐L pilot plant reactor. The matrix of variances of the parameter means (the prior knowledge) was estimated with the use of a preliminary compartment‐mixing (CM) model for PSD in suspension polymerization and our subjective judgement (process understanding). The responses, mean particle size and coefficient of variation, were calculated from distributions obtained with a Coulter particle counter. The results of this study provided the criteria needed to guide the future improvement of our CM‐PSD model in a balanced and effective way. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5577–5586, 2006
High‐resolution measurements of water permeability and solubility in microelectronic‐casing made of a hydrophobic polymeric composite
Authors: Zimrin Tomer , Haruvy Yaara Freeda , Margel Shlomo
Published: September 2006

Exposing the composite polymeric casing of integrated circuits (ICs) to water results in miniscule water absorption, followed by its permeation throughout the packaging, and component damage. Studying water penetration and solubility mechanisms in the IC casing is crucial for understanding water‐related damage mechanisms and protection against them. The main analytical challenge, hereafter, stems from the need to study miniscule water amounts (<0.5 wt %) capable of penetrating the casing, despite its hydrophobic nature. In this article, a TGA has been employed to study the water uptake kinetics in the casing, and to decipher the related water penetration mechanisms. High‐resolution measurements of water adsorption and desorption profiles were performed, followed by calculations of the related activation energies and solubility enthalpies. These data were correlated with a relatively new model that assigned the primary locales of the adsorbed water to the compatible filler–polymer interface. Thus, water permeability is related to molecules hopping between these sites. Finally, we have shown that for the IC casing in our study, the activation energy of water permeation is related to the binding energy of H2O onto the SiOSi groups at the fused‐silica‐filler surface, where they desorb, hop, and reabsorb. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4523–4527, 2006
Simulation of nonisothermal flow of melt during melting process of vibration‐induced polymer extruder
Authors: Feng Yan‐hong , Qu Jin‐ping , He He‐zhi , Jin Gang , Cao Xian‐wu , Song Jian
Published: September 2006

A simplified 2D melt film model was established to simulate the nonisothermal melt flow during the melting process of the vibration‐induced polymer extruder of which the screw can vibrate axially. Since polymer has time‐dependent nonlinear viscoelastic characteristic with vibration force filed (VFF), a self‐amended nonisothermal Maxwell constitutive equation that can reflect the relaxation time spectrum of polymer was adopted. Using the 2D melt film model, melt films of two kinds of thickness representing different melting stages were simulated to investigate the influence tendency of the same VFF on the different melting stage. Special flow patterns and temperature distribution of melt in the melt film between the driving wall and the solid/melt interface with various vibration force fields were systematically simulated. It is found out that within a certain range of vibration strength, the application of vibration can optimize the time‐averaged shear‐rate distribution, improve the utilization efficiency of energy, and promote melting process; and the thinner the melt film is, the more intense the nonlinear viscoelastic response becomes with the same VFF; moreover, there exists optimum vibration strength to make the melting process fastest, which is in accord with the visualization experimental results. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5825–5840, 2006
Photo‐patterning of smart light‐modulation gel
Authors: Tsutsui Hiroaki , Akashi Ryojiro
Published: September 2006

A novel method for fabricating desired patterns of smart light‐modulation gels, which consist of thermoresponsive N‐isopropylacrylamide (NIPAM) gel particles containing pigment, was developed. The patterns were fabricated by photo‐patterning of dispersion of colored NIPAM gel particles in photosensitive poly(vinylalcohol)‐styrylpyridinium solution. The pattern showed drastic color changes in response to the surrounding temperature changes. By repeated cycles of the patterning method, several independent patterns that contained different color particles were fabricated. In addition, a thermosensor array was also fabricated, which was constructed with independent patterns containing colored NIPAM gel having different color‐changing temperatures. The patterning method studied here is considered to have strong potential to extend the application field of the smart light‐modulation gels. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5351–5357, 2006
Synthesis and properties of novel deep red‐emitting copolymers based on a poly(p‐phenylenevinylene) derivative
Authors: Li Xianzhen , Zeng Wenjin , Xia Yangjun , Yang Wei , Cao Yong
Published: September 2006

A series of novel copolymers based on a poly(p‐phenylenevinylene) (PPV) derivative with different content of narrow band‐gap unit 2,1,3‐benzoselenadiazolevinylene (BSeV) was prepared via Stille coupling reaction. The copolymers emit light from deep red to near‐infrared (NIR) depending on BSeV content in the copolymers. The electroluminescence (EL) emission peaked at 752 nm for the copolymer with the content of 30 mol % BSeV is among the longest reported so far for the PPV polymers. The best device performance is observed for the copolymer with 1 mol % BSeV content with external quantum efficiency (QEext) of 0.26% and CIE coordinate 0.65, 0.34 (x,y). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4321–4327, 2006
Kinetics study of radiation‐grafting of acrylic acid, acrylonitrile, and their mixture onto wool fabric
Authors: El‐Gendy E. H. , El‐Shanshoury I. A.
Published: September 2006

The effect of monomer concentration, exposure time, irradiation temperature, and weaving direction on the kinetics of grafting acrylic acid (AA), acrylonitrile (AN), and their mixture onto wool fabric has been studied at the dose rate of 1.38 Gy/s. The degree of grafting is found to depend on the methanol‐to‐water solvent ratio and fabric‐to‐liquor ratio. The grafting rate and rate constant are dependent on irradiation temperature, type of grafted monomer, and weaving direction. The grafting rates increase with the increase in irradiation temperature (276–308 K). The calculated activation energy is nearly the same (16.4–17.2 kJ mol−1) and the preexponential rate constant is dependent on the type of grafted monomer. The grafting of AA, AN, and their mixture are confirmed from the dyeing affinity of grafted fabrics towards Sandocryl Blue (SB), a basic dye. The formation of wool grafts and structural changes resulting from grafting were verified by using FTIR spectrometry and X‐ray diffraction analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4328–4340, 2006
Adsorption behavior and effectiveness of poly(N,N‐dimethylacrylamide‐co‐Ca 2‐acrylamido‐2‐methylpropanesulfonate) as cement fluid loss additive in the presence of acetone‐formaldehyde‐sulfite dispersant
Authors: Plank Johann , Brandl Andreas , Zhai Yanan , Franke Agnieszka
Published: September 2006

A copolymer of N,N‐dimethylacrylamide and Calcium 2‐acrylamido‐2‐methylpropanesulfonate was synthesized by free‐radical copolymerization. Its performance as anionic fluid loss additive (FLA) was studied by measuring static filtration properties of oil well cement slurries at 27°C and 70 bar pressure, respectively. It was found that cement filter cake permeability and API fluid loss decrease with increasing FLA dosage. Filtrate analysis revealed a linear correlation between fluid loss and the amount of FLA adsorbed on the cement surface. FLA adsorption on cement was determined by total organic carbon (TOC) analysis in cement filtrate and confirmed by ζ‐potential measurement. According to environmental scanning electron microscopy (ESEM) investigations, FLA does not alter the filter cake structure. In the presence of an anionic acetone–formaldehyde–sulfite (AFS) polycondensate dispersant, fluid loss control from FLA decreased and cement filter cake permeability increased because AFS reduces the amount of FLA adsorbed. In comparison to FLA, AFS shows stronger adsorption on the cement surface and succeeds in the competition with FLA. The different adsorption behavior of the two polymers is the reason for limited compatibility of this admixture com bination. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4341–4347, 2006
Microstructure and glass‐transition temperature of novel star N‐SIBR
Authors: Wang Zhengsheng , Wang Yurong , Li Yang , Xu Hongde , Ren Yan , Zhang Chunqing
Published: September 2006

In this study, a polymeric N‐functionalized mutilithium (N‐M‐Li) compound was prepared from commercial divinylbenzene (DVB) and lithiohexamethyleneimine (LHMI), and star‐shaped copoly(styrene–butadiene–isoprene) was obtained by anionic polymerization using preformed N‐M‐Li as initiator, tetramethylethlenediamine (TMEDA) as polar modifier, and cyclohexane as solvent. The microstructure and the glass–transition temperature (Tg) of copolymers were characterized by 1H NMR and differential scanning calorimetry (DSC), respectively. It showed that the non‐1,4‐structure content and the Tg of copolymers increased with the increase of TMEDA dosage or the decrease of polymerization temperature; however, the effects of the initiator concentration and DVB dosage on them were not obvious. We also obtained the relationships between the non‐1,4‐structure content of copolymers and the Tg of copolymers respectively, and between the ln(T/Li) (TMEDA/N‐M‐Li, mole ratio) and the non‐1,4‐structure content of copolymers, as follows: Tg (°C) = 0.6258Cnon 1,4−55.93 and Cnon 1,4 = 20.79 ln K+59.11, where K is T/Li value. Therefore on the basis of experimental results, we realize polymer design according to our practical requirements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5848–5853, 2006
Partial substitution of cellulose by ring‐opening esterification of cyclic esters in a homogeneous system
Authors: Mayumi Ayaka , Kitaoka Takuya , Wariishi Hiroyuki
Published: September 2006

Partially substituted cellulose derivatives were prepared by the regioselective derivatization of cellulose with cyclic esters (CEs), L‐lactide (LA), and ε‐caprolactone (CL), in a lithium chloride (LiCl)/N,N‐dimethylacetamide solvent. They were characterized by spectroscopic analyses, calorimetry, solvent solubility inspection, and an enzymatic degradability test. Fourier transform Raman spectra of the cellulose derivatives confirmed that the CE moieties were covalently introduced into cellulose molecules at their hydroxyl groups via ring‐opening esterification through the catalysis by LiCl. The 13C‐NMR analysis indicated that the ring‐opened CEs were regioselectively combined with cellulose C6‐OH. The CE portions were partially grafted on the cellulose backbone; the degree of substitution was ca. 0.5–0.7 and the degree of polymerization of grafted CEs was less than 3. Both cellulose derivatives were highly soluble in dimethylsulfoxide, which allows material fabrication. Some of the cellulose‐LA was soluble or swollen in water, while cellulose‐CL had poor affinity for water. Enzymatic degradation of cellulose‐CEs occurred immediately on cellulase treatment, even under mild conditions which are not able to hydrolyze commercial cellulose diacetate at all. Some cellulose derivatives displayed endothermic changes. The cellulose derivatives prepared in this study are expected to be used as cellulose‐based biomaterials with environmentally friendly features. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4358–4364, 2006
Structure and properties of polypropylene composites filled with magnesium hydroxide
Authors: Chen Xiaolang , Yu Jie , Guo Shaoyun
Published: September 2006

Silane and silicone oil modified superfine magnesium hydroxide (MH) was filled into polypropylene (PP) as a flame retardant. The PP and flame‐retarded PP composites were studied for their mechanical properties and rheological behaviors by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), limiting oxygen index (LOI), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that the addition of MH improved flame retardancy of PP/MH composites, but seriously deteriorated mechanical properties of the composites. Surface treatment of MH could significantly improve tensile and impact strength of PP/MH composite because of its enhanced interfacial adhesion between MH and PP matrix. DSC results showed that MH had heterogeneous nucleation effect on PP. Surface treatment of MH weakened its heterogeneous nucleation effect. POM results showed that the dispersion of MH particles played an important role in the crystalline morphology and spherulite size of PP crystals. TGA indicated that MH greatly enhanced the thermal stability of PP. The introduction of treatment agent further improved the thermal oxidative stability of the composite. According to LOI, silane‐treated MH greatly enhanced flame retardancy of PP/MH composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4943–4951, 2006