Modification of carbon black pigment: Cotton fabric colouring and anti‐bacterial finishing

Functional polymer modified carbon black (CB) pigment (P‐(DMC‐co‐CHPMA)‐g‐MPTS/CB) with reactive epoxy and quaternary ammonium groups was designed and prepared via a thiol‐ene click chemistry reaction, and its dispersion ability in the aqueous phase, as well as its colouring and anti‐bacterial properties for cotton fabrics, were investigated. In considering both dispersion ability and reactive ability to cotton fabric, the mole ratio of the monomers (methacrylatoethyl trimethyl ammonium chloride [DMC] and 3‐chloro‐2‐hydroxypropyl methacrylate [CHPMA]) was discussed. Morphology and chemical properties of P‐(DMC‐co‐CHPMA)‐g‐MPTS/CB were tested by scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis and X‐ray photoelectron spectroscopy, resulting in a weight content of copolymer (DMC‐co‐CHPMA) in P‐(DMC‐co‐CHPMA)‐g‐MPTS/CB of ca. 18%. P‐(DMC‐co‐CHPMA)‐g‐MPTS/CB was fixed onto cotton fabric via a nucleophilic‐substituted reaction between reactive epoxy groups on the CB surface and the hydroxyl groups of cotton fabric, which endowed good fastness to cotton fabric without either a fixing or an adhesive agent. Also, coloured cotton fabric demonstrated excellent anti‐bacterial activity towards Staphylococcus aureus and Escherichia coli O157:H7.     

Synthesis of UV‐curable/alkali‐soluble dispersants used for black photoresist with a high loading of carbon black

This research synthesized a functional dispersant, not only providing a good dispersion of carbon black (CB) but also possessing ultraviolet (UV)‐curable and alkali‐soluble properties, by a two‐step process. Firstly, bisphenol‐A epoxy diacrylate was reacted with benzophenone tetracarboxylic dianhydride at different molar ratios to obtain UV‐curable/alkali‐soluble resins. In the second step, these resins would possess dispersion ability of CB by reaction with an isocyanate‐containing methacrylate. The prepared dispersants were evaluated by their dispersion ability and the light absorption property of CB. The results showed that one of the dispersants was able to disperse CB in the solvent up to 10 wt % with a mean particle size about 100 nm. This particular dispersant had a moderate amount of amino‐containing groups (such as urethane, amide, and imide) serving as anchoring sites on CB, and a sufficiently long chain (M_n ～ 2600) to provide a steric repulsion among CB particles. The advantage of this CB/dispersant system is that no other curable resins are needed. By using a suitable photoinitiator, the present CB/dispersant system could reach a polymerization rate of 1.05 × 10^?3 (s^–1), and a black pattern of 10 μm in width on a glass substrate was obtained through an UV‐lithography process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Heterocoagulation behavior of carbon black with surface encapsulation through emulsion polymerization

Nanocomposite microspheres containing styrene–acrylate resin, wax, and carbon black (CB) with desired CB dispersion were prepared through heterocoagulation. The CB surface was modified using conventional anionic emulsifier and anionic dispersants with different lengths of nonionic chains and reactivities or through polymer encapsulation via emulsion polymerization to regulate the dispersion and concentration of CB in the microspheres. Experimental results showed that anionic dispersants with long nonionic chains effectively dispersed and stabilized CB particles. Polystyrene (PS) was then encapsulated on the CB surface by using a reactive dispersant and a water‐soluble initiator of polymerization. The CB particles exhibited comparable pH stability with other heterocoagulation components. Overall, encapsulation through emulsion polymerization can be used to obtain not only high CB content but also improved CB distribution in the resulting microspheres. High coagulation efficiency can also be achieved using polystyrene‐encapsulated dispersed CB because of its high affinity to emulsifiers and reactive dispersants during dispersion. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43516.     

Mechanism and properties of coloured nanoscale SiO2 prepared from silica and reactive dyes

KH560‐modified SiO₂ was prepared using tetraethyl orthosilicate (TEOS) and γ‐(2,3‐epoxypropoxy) propytrimethoxysilane (KH560) by the sol–gel method and then coloured with CI Reactive Blue 4 (X‐BR) to prepare coloured nanoscale SiO₂. The antisolvent performance and the results of cross‐polarisation/magic angle spinning ¹³C nuclear magnetic resonance and Fourier transform infrared spectroscopy showed that the reaction of X‐BR with KH560‐modified SiO₂ is a two‐step process: X‐BR is firstly adsorbed by KH560‐modified SiO₂ via van der Waals forces, and then nucleophilic substitution occurs between dichloro triazine and the epoxy group. The grafting ratio of X‐BR on KH560‐modified SiO₂ reached 95% under optimum conditions, i.e. a mass ratio of KH560 to TEOS of 20%, a temperature of 40 °C, a pH of 8.5, and a reaction time of 5 h. X‐ray diffraction analysis and transmission electron microscopy showed that the coloured nanoscale SiO₂ was amorphous, with a mean diameter of 216 nm. Experimental application showed that the coloured nanoscale SiO₂ had excellent stability to solvents and alkaline solution, and the absorptive capacity of the coloured nanoscale SiO₂ in the 200–400 nm region was higher than that of X‐BR. The light fastness of the coloured nanoscale SiO₂ reached 5–6 grade.     

Effect of coupling agent on structure and properties of micro–nano composite fibers based on PET

Poly(ethylene terephthalate) (PET)/carbon black (CB) micro–nano composite fibers were manufactured by melt spinning method. To achieve good dispersion, nano‐CB particles were modified by coupling agent (CA). The effect of CA on structure and properties of the fibers were investigated via scanning electron microscopy (SEM), tensile testing, differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), sonic orientation, and birefringence, respectively. At 2 wt % CA dosage, CB particles present the optimal dispersion in the fibers, shown in SEM images. Besides, the fibers possess the maximum breaking strength, the lowest crystallization temperature, and the highest crystallinity. After CA modification, the superior interfacial structure between PET and CB is beneficial to improve mechanical properties of the fibers. The well dispersed CB particles provide more heterogeneous nucleation points, resulting in the highest crystallinity. Furthermore, the fibers with 2 wt % CA dosage possess the maximum orientation and shrinkage ratio. According to Viogt–Kelvin model, the thermal shrinkage curves of the fibers can be well fitted using single exponential function. The three‐phase structure model of crystal phase–amorphous phase–CB phase was established to interpret the relationship among shrinkage, orientation, and dispersion of CB particles. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43846.     

Synthesis and characterization of alkali‐modified styrene‐maleic anhydride copolymer for dispersion of TiO2

A copolymer of styrene and maleic anhydride was synthesized by free radical polymerization at 80°C using N,N‐dimethylformamide (DMF) as solvent and benzoylperoxide as initiator. The monomer feed ratio of styrene to maleic anhydride was varied in the range of 1 : 1 : to 3 : 1. The polymer yield was found to decrease with increase in styrene in the feed. The molecular weight of copolymers which were formed by taking styrene to maleic anhydride ratio of 1 : 1, 2 : 1, and 3 : 1, as determined by Ostwald Viscometery were about 1862, 2015, and 2276 respectively. The acid values of abovementioned three copolymers were found to be 480, 357, and 295, respectively. The typical viscosity values of 20% solids in ammonical solution of copolymers formed by taking feed ratios of Sty : MAn as 1 : 1 and 2 : 1 were 26 and 136 cp, respectively. For the feed ratio 3 : 1, a gel was formed. The synthesized copolymers were hydrolyzed by alkalis, namely, NaOH, KOH, and NH₄OH. The dispersing ability of hydrolyzed styrene‐maleic anhydride (SMA) copolymers for dispersion of titanium dioxide was studied. The modified SMA copolymers were found to be effective dispersants for TiO₂. Among the three alkalis studied, the Sodium salts of SMA were found to give better dispersion. The copolymer having a 1 : 1 feed ratio showed the best dispersing ability for TiO₂ particles among the three ratios studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3194–3205, 2007     

Preparation and characterization of polyurethane microcapsules containing n‐octadecane with styrene‐maleic anhydride as a surfactant by interfacial polycondensation

A series of polyurethane microcapsules containing a phase change material (PCM) of n‐octadecane was successfully synthesized by an interfacial polymerization in aqueous styrene‐maleic anhydride (SMA) dispersion with diethylene triamine (DETA) as a chain extender reacting with toluene‐2,4‐diisocyanate (TDI). The average diameter of microPCMs is in the range of 5–10 μm under the stirring speed of 3000–4000 rpm. Optical and SEM morphologies of microPCMs had ensured that the shell was regularly fabricated with the influence of SMA. FTIR results confirmed that the shell material was polyurethane and the SMA chains associated on core material reacted with TDI forming a part of shell material. The shell thickness was decreasing in the range of 0.31–0.55 μm with the molar ratio of DETA/TDI from 0.84 to 1.35 and the weight of core material increasing from 40 to 80% (wt %). By controlling the weight ratio of PCM as 40, 50, 60, 70, and 80% in microPCMs, it was found using DSC that the T_m and T_c of microPCMs were in the range of 29.8–31.0^oC and 21.1–22.0°C and an obvious phase change had been achieved nearly the same temperature range of that of PCM. The results from release curves of microPCM samples prepared by 1.4, 1.7, and 2.0 g of SMA indicated the release properties were affected by the amount of the dispersant, which attributed to the emulsion effect and shell polymerization structure. The above results suggest that the shell structure of microPCMs can be controlled and the properties of microPCMs determined by shell will perform proper practical usage. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4996–5006, 2006     

Synthesis and properties of natural rubber modified with stearyl methacrylate and divinylbenzene by graft polymerization

The graft polymerizations of stearyl methacrylate (SMA) and divinylbenzene (DVB) onto natural rubber (NR) were carried out in a solution process using benzoyl peroxide (BPO) as an initiator in toluene or chloroform. The main products of the grafted NR include an uncrosslinked (sol) part [sol(SMA–NR–DVB): s‐SNRD] and a crosslinked (gel) part [gel(SMA–NR–DVB), g‐SNRD]. s‐SNRD was obtained by extraction using tetrahydrofuran. It was identified by IR and ¹H‐NMR spectroscopies. The glass transition temperature (T_g) and thermal properties of s‐SNRD and g‐SNRD were studied by DSC and TGA. The glass transition temperature and thermal decomposition temperature of s‐SNRD and g‐SNRD were higher than were those of NR. The light resistance and weatherability of s‐SNRD were measured with a Weather‐o‐Meter. The light resistance and weatherability of s‐SNRD are better than are those of NR. The effects of the initiator concentration, mol ratio of SMA to DVB, reaction time, temperature on grafting ratio, and crosslinking ratio were investigated. The highest grafting ratio and crosslinking ratio in the graft polymerization of SMA and DVB onto NR were obtained when the mol ratio of SMA to DVB and BPO were 4.0 and 2 wt %, at 80°C for 48 h, respectively. Following several studies on oil‐absorptive polymers in our laboratory, 9 the oil absorptivity of g‐SNRD was examined using crude oil. The oil absorptivity of g‐SNRD was 600% when the immersion time was 10 min. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2464–2470, 2001     

Polymer blends with modified coupling agent. II. Effects of LICA 44 grafted styrene–maleic anhydride copolymer on properties of flame retardant acrylonitrile–butadiene–styrene blends

Flame retardant acrylonitrile–butadiene–styrene (FR‐ABS) blends were prepared by blending tetrabromobisphenol A (TBBA) and antimony trioxide (Sb₂O₃) into the ABS resin. LICA 44 grafted styrene–maleic anhydride (SMA‐g‐L44) copolymers were used as high molecular weight (MW) coupling agents to modify the properties of the FR‐ABS blends, and the copolymers with different LICA 44 grafting ratios were produced via the in vivo and the in situ reactions, respectively. The LICA 44 percentage and the MW of the SMA‐g‐L44 copolymers are important factors influencing the effects of the high MW coupling agent. The impact strength and the tensile yield stress of SMA‐g‐L44 modified FR‐ABS blends increased obviously. The elongation at break and the limiting oxygen index of which also showed an increasing trend after the modification. The coupling effect of SMA‐g‐L44 became weaker at a higher grafting ratio. SEM observation showed that the interfacial boundary in the FR‐ABS became fuzzy after using the SMA‐g‐L44 copolymers. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 865–874, 1999     

In vitro cadmium removal from human serum by Cibacron Blue F3GA–thionein‐complex conjugated affinity membranes

A new membrane affinity biosorbent carrying thionein has been developed for selective removal of cadmium ions from human serum. Microporous poly(2‐hydroxyethyl methacrylate) (pHEMA) membranes were prepared by photopolymerization of HEMA. The pseudo dye ligand Cibacron Blue F3GA (CB) was covalently immobilized on the pHEMA membranes. Then, the cysteine‐rich metallopeptide thionein was conjugated onto the CB‐immobilized membrane. The maximum amounts of CB immobilized and thionein conjugated on the membranes were 1.07 µmol cm⁻² and 0.92 µmol cm⁻², respectively. The hydrophilic pHEMA membrane had a swelling ratio of 58% (w/w) with a contact angle of 45.8 °. CB‐immobilized and CB‐immobilized–thionein‐conjugated membranes were used in the Cd(II) removal studies. Cd(II) ion adsorption appeared to reach equilibrium within 30 min and to follow a typical Langmuir adsorption isotherm. The maximum capacity (q _m) of the CB‐immobilized membranes was 0.203 (µmol Cd(II)) cm⁻² membrane and increased to 1.48 (µmol Cd(II)) cm⁻² upon CB–thionein‐complex conjugation. The pHEMA membranes retained their cadmium adsorption capacity even after 10 cycles of repeated use. © 2000 Society of Chemical Industry     

Preparation,surface wetting properties,and protein adsorption resistance of well‐defined amphiphilic fluorinated diblock copolymers

Novel well‐defined amphiphilic fluorinated diblock copolymers P(PEGMA‐co‐MMA)‐b‐PC₆SMA were synthesized successfully by RAFT polymerization and characterized by FTIR, ¹HNMR and GPC. For copolymer coatings, static contact angles, θ, with water (θ_water ≥ 109.5^°) and n‐hexadecane (θ_hexadecane ≥ 68.9^°) pointed to the simultaneous hydrophobic and lipophobic characteristics of the copolymer surfaces. Dynamic contact angle measurements indirectly demonstrated that copolymer films underwent surface reconstruction upon contact with water, which results in a surface with surface coverage of polar PEG units. Moreover, the distinct nanoscale microphase segregation structures were proved by atomic force microscopy (AFM) images. Finally, using bovine serum albumin (BSA–FITC) as the model protein, copolymers exhibited excellent protein adsorption resistance. It is believed that the combination of surface reorganization and nanometer‐scale microphase segregation structure endows the excellent protein resistance for amphiphilic fluorinated copolymers. These results provide deeper insight of the effect of surface reconstruction and microphase segregation on the protein adsorption behaviors, and these amphiphilic fluoropolymers can expect to have potential applications as antifouling coatings in the field of marine and biomedical. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41167.     

Reactive melt blending of PS‐POSS hybrid nanocomposites

Hybrid nanocomposites of polystyrene (PS) and methacryl phenyl polyhedral oligomeric silsesquioxane (POSS) were synthesized by reactive melt blending in the mixing chamber of a torque rheometer using dicumyl peroxide (DCP) as a free radical initiator and styrene monomer as a chain transfer agent. The effects of mixing intensity and composition on the molecular structure and morphology of the PS‐POSS hybrid nanocomposites were investigated. The degree of POSS hybridization (α_POSS) was found to increase with the POSS content, DCP/POSS ratio, and rotor speed. For the PS‐POSS materials processed in the absence of styrene monomer, an increase in the α_POSS led to a reduction in the molecular weight by PS chain scission, as a consequence of the free radical initiation. On the other hand, the use of styrene monomer as a chain transfer agent reduces the steric hindrance in the hybridization reaction between POSS and PS, enhancing the degree of POSS hybridization and avoiding PS degradation. The PS‐POSS morphology consists of nanoscale POSS clusters and particles and microscale crystalline POSS aggregates. PS‐POSS with higher α_POSS values and lower amounts of nonbound POSS showed improved POSS dispersion, characterized by smaller interfacial thickness (t) and greater Porod inhomogeneity lengths (l_p). The processing‐molecular structure–morphology correlations analyzed in this study allow the POSS dispersion level in the PS‐POSS materials to be tuned by controlling the reactive melt blending through the choice of the processing conditions. These insights are very useful for the development of PS‐POSS materials with optimized performance. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Vibration damping and electrical conductivity of styrene–butyl acrylate random copolymers filled with carbon black

Emulsion‐polymerized poly(styrene‐rand‐butyl acrylate) (St–BA) copolymers exhibit damping capabilities over a wide temperature range with changes in the monomer ratio. Blending copolymers of different compositions results in a multidamping peak, further widening the effective damping temperature range. Adding carbon black (CB) reduces the peak damping intensity but enhances damping at higher temperatures. The addition of dodecyl benzene sulfonic acid to an St–BA/CB aqueous dispersion improves the dispersion of CB in the polymer, reducing the percolation threshold and improving the conductivity while slightly affecting the mechanical behavior. The electrical properties of the St–BA/CB system are affected by the copolymer composition, influencing the polymer surface tension. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Miniemulsion copolymerizations of methyl methacrylate and butyl acrylate in the presence of reactive costabilizer

The storage stability and free radical polymerizations of miniemulsions comprising methyl methacrylate (MMA), butyl acrylate (BA), and a reactive costabilizer stearyl methacrylate (SMA) were investigated. The Ostwald ripening rate increases with increasing MMA content in the monomer mixture. Both the pseudo‐two‐component model and empirical equation with one adjustable parameter k adequately predicted the Ostwald ripening rate data. For the empirical model, the least‐squares best fit technique gave a value of k equal to 677.5 and values of Ostwald ripening rate and water solubility equal to (8.8 ± 0.2) × 10^?21 cm³/s and 1.8 × 10^?9 cm³/cm³ for SMA, respectively. These two models were combined to impart some physical insight to the parameter k. The kinetic studies showed that the polymerization rate increased with increasing MMA content. This is closely related to the nature of the constituent monomers MMA and BA and the particle nucleation mechanisms. The reactive costabilizer SMA is not hydrophobic enough to completely eliminate the Ostwald ripening effect, thereby increasing the probability of polymer reactions in the continuous aqueous phase. Thus, in addition to monomer droplet nucleation, particle nuclei can be generated in the aqueous phase via homogeneous nucleation. The extent of homogeneous nucleation increased with increasing MMA content and, as a result, the number of reaction loci available for the major polymerization to take place followed the same trend. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Dispersion and resistivity optimization of conductive carbon black in environment‐friendly conductive coating based on acrylic resin

A designated chemical structure, determined through the analysis of elements and groups on the surface of conductive carbon black (CB), alcohol‐soluble acrylic resin used for dispersion of conductive CB was successfully prepared based on the principles of similar structure complex well. The content of acrylic acid, glass transition temperature (T_g), molecular weight (M_w), self‐crosslinking degree, and N‐hydroxymethyl acrylamide content were investigated to optimize the electrical conductivity and dispersion effect of conductive CB in coating. The composites of acrylic resin and conductive CB were characterized by X‐ray photoelectron spectroscopy for surface chemical structure on CB, scanning electron microscopy for morphology of conductive coating, Fourier transform infrared for groups in acrylic resin, and digital multimeter techniques for surface resistivity of conductive coating. The optimum surface resistivity of the acquired conductive coating could reach 600 ohm/sq, showing an excellent conductive property. Moreover, the conductive coating still maintained a lower resistivity after salt spray and weather resistance test. POLYM. COMPOS. 36:467–474, 2015. © 2014 Society of Plastics Engineers     

Deep Inside Cucurbiturils: Physical Properties and Volumes of their Inner Cavity Determine the Hydrophobic Driving Force for Host–Guest Complexation

Cucurbit[n]urils (CBn) bind guest molecules through a combination of electrostatic interactions with the carbonyl rims and hydrophobic interactions with the inner cavity. Investigations with solvatochromic probes in CB7 reveal that the polarity of the cavity resembles that of alcohols (e.g., n-octanol), while its polarizability (P=0.12) and apparent refractive index (n_D=1.10±0.12) are extremely low, close to the gas phase. The calculated molecular quadrupole moments of CBs are extremely large (Θ_zz=−120 to −340 Buckingham). A survey of reported binding constants of neutral guests and hydrophobic residues that form 1 : 1 inclusion complexes with CB6, reveals a preferential inclusion of C3–C5 residues in its cavity. The largest guests which show non-negligible binding contain 7 heavy atoms (excluding hydrogen). For CB7, the strongest binding is observed for guests with adamantyl (10 heavy atoms) and ferrocenyl groups (11 heavy atoms), while the largest guests known to be complexed are carborane and the adduct of two pyridine derivatives (12 heavy atoms). The evaluation of different volumes shows that the most meaningful cavity, namely that responsible for binding of hydrophobic residues, is confined by the planes through the oxygen carbonyls. The volume of this inner cavity follows the formula V/ų=68+62(n−5)+12.5(n−5)², affording representative cavity volumes of 68 ų for CB5, 142 ų for CB6, 242 ų for CB7, and 367 ų for CB8. The volume of the 2 bond dipole regions is comparably smaller, amounting, for example, to 2×35 ų for CB6. The analysis of packing coefficients for representative sets of known guests with clearly defined hydrophobic binding motifs reveals average values of 47 % for CB5, 58 % for CB6, 52 % for CB7, and 53 % for CB8, which are well in line with the preferred packing (“55 % solution”, see S. Mecozzi, J. Rebek, Chem. Eur. J. 1998 , 4, 1016–1022) in related supramolecular host–guest assemblies. The driving force for binding of hydrophobic guests and residues by CBs is interpreted in terms of the unimportance of dispersion interactions (owing to the low polarizability of their cavity) and the dominance of classical and nonclassical hydrophobic effects related to the removal of very-high-energy water molecules (2 for CB5, 4 for CB6, 8 for CB7, and 12 for CB8) from the cavity.     

Preparation and properties of porous poly(sodium acrylate‐co‐acrylamide) salt‐resistant superabsorbent composite

A novel semi‐interpenetrating polymer networks (semi‐IPNs) porous salt‐resistant superabsorbent composite was prepared by copolymerization of partially neutralized acrylic acid and acrylamide using polyethylene glycol as semi‐IPNs composite, N,N′‐methylenebisacrylamide, triene propanol phosphate, and trihydroxymethyl propane glycidol ether as crosslinking agents, methanol, propanol, and butanol as foaming agents, and L ‐ascorbic acid and peroxide hydrogen as initiators. To improve the properties of swollen hydrogel, such as strength, resilience, permeabilities, and dispersion, the copolymer was surface‐crosslinked, and then blended with aluminum sulfate, sodium carbonate, and sodium 1‐octadecanol phosphate in the course of post treatment. The influences of reaction conditions on properties of superabsorbent composite were investigated and optimized, and the water absorbency of superabsorbent composite prepared at optimal conditions in 0.9 wt% NaCl aqueous solution under atmospheric pressure and certain load (P ≈ 2 × 10³ Pa) were 61 g g^?1 and 16.7 g g^?1, respectively. Moreover, the swelling rate reached 22.003 × 10^?3 g (g s)^?1. And the excellent hydrogel properties, such as hydrogel strength, resilience, permeabilities, and dispersion were also obtained. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Novel comb‐structured‐polymer‐grafted carbon black by surface‐initiated atom transfer radical polymerization and ring‐opening polymerization

Novel comb‐structured‐polymer‐grafted carbon black (CB) was synthesized with a combination of surface‐initiated atom transfer radical polymerization and ring‐opening polymerization. First, poly(2‐hydroxyethyl methacrylate) (PHEMA) was grafted onto the CB surface by surface‐initiated atom transfer radical polymerization. The prepared CB‐g‐PHEMA contained 35.6–71.8% PHEMA, with the percentage depending on the molar ratio of the reagents and the reaction temperature. Then, with PHEMA in CB‐g‐PHEMA as the macroinitiator, poly(?‐caprolactone) (PCL) was grown from the CB‐g‐PHEMA surface by ring‐opening polymerization in the presence of stannous octoate. CB‐g‐PHEMA and CB‐g‐(PHEMA‐g‐PCL) were characterized with Fourier transform infrared, ¹H‐NMR, thermogravimetric analysis, dynamic light scattering, and transmission electron microscopy. The resultant grafted CB had a shell of PHEMA‐g‐PCL. On the whole, the CB nanoparticles were oriented in dendritic lamellae formed by these shells. This hopefully will result in applications in gas sensor materials and nanoparticle patterns. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Morphology and thermal behavior of organo‐bentonite clay/poly(styrene‐co‐methacrylic acid)/poly(isobutyl methacrylate‐co‐4‐vinylpyridine) nanocomposites

Poly(styrene‐co‐methacrylic acid) containing 29 mol % of methacrylic acid (SMA‐29) and poly(isobutyl methacrylate‐co‐4‐vinylpyridine) containing 20 mol % of 4‐vinylpyridine (IBM4VP‐20) were synthesized, characterized, and used to elaborate binary and ternary nanocomposites of different ratios with a 3% by weight hexadecylammonium‐modified bentonite from Maghnia (Algeria) by casting method from tetrahydrofuran (THF) solutions. The morphology and the thermal behavior of these binary and ternary elaborated nanocomposites were investigated by X‐ray diffraction, scanning electron microscopy, FTIR spectroscopy, differential scanning calorimetry, and thermogravimetry. Polymer nanocomposites and nanoblends of different morphologies were obtained. The effect of the organoclay and its dispersion within the blend matrix on the phase behavior of the miscible SMA29/IBM4VP20 blends is discussed. The obtained results showed that increasing the amount of SMA29 in the IBM4VP20/SMA29 blend leads to near exfoliated nanostructure with significantly improved thermal stability. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Characterization of epoxy foams

Epoxy foams were prepared from the commercial system (LY 5054 epoxy resin, HY 5054 amine as curing agent, and DY 5054 siloxane as foaming agent) supplied by Ciba‐Geigy. From the differential scanning calorimeter results the optimal epoxy–amine ratio was determined. A maximum T_g∞ value of 85°C was found for an epoxy–amine ratio of 100:35 by weight. In this system, the siloxane reacts with the amine releasing hydrogen that acts as the real foaming agent. The density decreased from 490 to 215 kg/m³ as the epoxy:blowing agent ratio increased from 100:1 to 100:3 by weight of the reactive mixture. Under the synthesizing conditions, the glass transition temperature (T_g∞) of the foam did not vary significantly as the blowing agent increased. The modulus and compressive strength of the foam exhibited a power‐law dependence with respect to density of the form: E∝(ρ)ⁿ, where n=1.8. Scanning electron microscopy analysis verified that the foam have a closed cell structure. The relation between composition, final morphology, density, and properties of the foam was analyzed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2992–2996, 2003