Preparation and properties of poly(ether‐ester‐amide)/poly(acrylonitrile‐co‐butadiene‐co‐styrene) antistatic blends

A novel antistatic agent poly(ether‐ester‐amide) (PEEA) based on caprolactam, polyethylene glycol, and 6‐aminocaproic acid was successfully synthesized by melting polycondensation. The structure, thermal properties, and antistatic ability of the copolymer were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analyses, and ZC36 megohmmeter. Test results show that PEEA is a block copolymer with a melting point of 217°C and a thermal decomposition temperature of 409°C, together with a surface resistivity of 10⁸ Ω/sq. Antistatic poly(acrylonitrile‐co‐butadiene‐co‐styrene) (ABS) materials were prepared by blending different content of PEEA to ABS resin. The antistatic performances, morphology, and mechanical properties were investigated. It is indicated that the surface resistivity of PEEA/ABS blends decrease with the increasing PEEA content, and the excellent antistatic performance is obtained when the antistatic agent is up to 10–15%. The antistatic performance is hardly influenced by water‐washing and relative humidity, and a permanent antistatic performance is available. The antistatic mechanism is investigated. The compatibility of the blends was studied by scanning electron microscopy images. The ladder distribution of antistatic agent is formed, and a rich phase of antistatic agent can be found in the surface layer. The elongations at break of the blend are improved with the increasing antistatic agent; the tensile strength and the notched impact strength kept almost the same. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

Effect of the ionic liquid [bmim]PF6 on the nonisothermal crystallization kinetics behavior of poly(ether‐b‐amide)

Blending ionic liquid with crystalline polymer permits the design of new high‐performance composite materials. The final properties of these materials are critically depended on the degree of crystallinity and the nature of crystalline morphology. In this work, nonisothermal crystallization behavior of poly(ether‐b‐amide) (Pebax®1657)/room temperature ionic liquid (1‐butyl‐3‐methylimidazolium hexafluorophosphate, [bmim]PF₆) was investigated by differential scanning calorimetry. The presence of [bmim]PF₆ can retard the nucleation of Pebax®1657 and lead to the crystallization depression of the PA block and the crystalline disappearance of the PEO block. However, the dilution effect of the IL results in a higher growth rate of crystallization of PA block. The influence of [bmim]PF₆ content and cooling rate on crystallization mechanism and spherulitc structures was determined by the Avrami equation modified by Jeziorny and Mo's methods, whereas the Ozawa's approach fails to describe the nonisothermal crystallization behavior of Pebax®1657/[bmim]PF₆ blends. In the modified Avrami analysis, the Avrami exponent of PA blocks, n > 3, for pure Pebax®1657, while 3 > n > 2 for Pebax®1657/[bmim]PF₆ blends testifies the transformation of crystallization growth pattern induced by [bmim]PF₆ from three‐dimensional growth of spherulites to a combination of two‐ and three‐dimensional spherulitic growth. Further, lower activation energy for the nonisothermal crystallization of PA blocks of Pebax®1657 can be observed with the increase of [bmim]PF₆ content. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42137.     

Optically active poly(ester‐amide)s: synthesis and characterization

The synthesis and characterization of a new series of chiral poly(ester‐amide)s are reported. They were prepared by the simple reaction of diacid chlorides with biphenolic azo chromophores and optically active dihydroxy compound (isosorbide) in dimethyl acetamide at 100 °C. The polymers containing isosorbide units were optically active. The polymers showed T_g between 100 and 190 °C and were stable up to 400 °C. These poly(ester‐amide)s showed a positive solvatochromism in UV–visible absorption spectra. Second harmonic generation activities were measured by the powder method. © 2001 Society of Chemical Industry     

Effect of thermomechanical history on the crystallization of poly(ether‐block‐amide)

The quiescent and flow‐induced crystallization of a poly(ether‐block‐amide) is studied by means of rheo‐optical methods. Both optical microscopy and small angle light scattering have been used. The multiblock copolymer has a microphase‐separated structure with an order–disorder transition at 180–185°C, as measured with rheometry and SAXS. The number of nuclei, spherulitic growth rates, and the characteristic time scale for crystallization are compared with that of a polyamide of similar molar mass. For the poly(ether‐block‐amide)—containing a majority of amide segments—the growth rates of the spherulites during quiescent crystallization are similar for the block copolymer and the homopolymer, even if the spherulitic structures are not the same. When flow is applied, the two materials behave differently. The flow increased the nucleation density in the homopolymer but not in the block copolymer. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Shape memory property and underlying mechanism by the phase separation control of poly(ϵ‐caprolactone)/poly(ether‐b‐amide)

In this work, a poly(?‐caprolactone)/poly(ether‐b‐amide) blend with weight ratio 35/65 was prepared by solution mixing and compression molding. A simple and sensible method to control the phase separation structure was introduced by adjusting the temperature and time for the process of phase separation. Samples with obviously different morphology were obtained and the microstructure was studied by phase contrast optical microscopy, SEM and DSC. The shape memory properties were measured using dynamic mechanical analysis. The results show that the shape memory performance of the blend is closely related to the phase morphology, and the blend with co‐continuous structure has a better shape memory property. A model is put forward to illustrate schematically the microstructural evolution during the shape memory process. © 2018 Society of Chemical Industry     

Tailor‐made unsaturated poly(ester‐ amide) network that contains monomeric lactate sequences

A novel unsaturated poly(ester‐amide) network (UPEAN) that contains isolated C? C double bonds, monomeric lactate sequences, rigid benzyl side‐groups, amide groups and crosslinking points has been designed and synthesized. The structure of the intermediate and UPEAN was verified with Fourier transform infrared spectroscopy. Pores in UPEAN generated in situ were examined with scanning electron microscopy. Differential scanning calorimetry analysis shows that UPEAN is amorphous and its glass transition temperature is around 34 °C. It is found that UPEAN exhibits thermosensitive shape‐recovery characteristics. The maximum percentage weight loss of UPEAN is 10 and 42% after immersing the samples in active sludge at ambient temperature for 146 days and in 0.1 mol L^?1 phosphate‐buffer saline at 37 °C for 103 days, respectively, which suggests that UPEAN is degradable. Copyright © 2007 Society of Chemical Industry     

Main‐chain liquid crystalline poly(ester‐amide)s containing lithocholic acid units

A series of poly(ester‐amide)s based on an ester group containing lithocholic acid derivative [3‐(3‐carboxypropionyl) lithocholic acid] and several aromatic diamines (naphthalene‐1,5‐diamine, 4,4′‐diaminodiphenyl ether, 4,4′‐diaminodiphenylmethane, 4,4′‐diaminodiphenylsulfone, benzidine, m‐phenylenediamine, p‐phenylenediamine, and tetraphenylthiophene diamine) was synthesized and characterized by solubility, viscosity, IR, differential scanning calorimetry, thermogravimetric analysis, and optical microscopy. The polymers were soluble in most of the organic solvents and had inherent viscosities in the range of 0.21–0.38 dL/g. All the polymers exhibited a nematic mesophase, but only on shearing. Thermal transitions due to mesophase formation were not seen in the differential scanning calorimetry thermograms. However, the liquid crystalline character of the polymers was observed under an optical microscope. Thermogravimetric analyses revealed the maximum decomposition temperature was 390–435°C for these polymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 73–80, 2006     

Hydroxyapatite (n‐HA)/unsaturated poly(ester‐amide) nanocomposites for bone fixation material

A new type of unsaturated poly(ester‐amide) viz maleic anhydride‐phthalic anhydride‐ethylene glycol‐neopentylene glycol‐glycin copolymer was prepared by melt polycondensation. The copolymer was characterized by FT‐IR, gel permeation chromatography, and thermal gravimetric analysis. The molecular structure of crosslinked unsaturated poly(ester‐amide) was determined by wide‐angle X‐ray diffraction. Hydroxyapatite (n‐HA) was used to boost up the new unsaturated poly (ester‐amide), the flexural properties of n‐HA/unsaturated poly(ester‐amide) nanocomposites with different n‐HA content were measured. Studies of degradation behavior were carried out in simulated body fluid at pH 7.4 and 37°C, the flexural strength changes and cumulative mass loss of n‐HA/ unsaturated poly(ester‐amide) nanocomposites were measured at different degradation times. The n‐HA/unsaturated poly(ester‐amide) nanocomposites was hydrolyzed in 1M NaOH standard solution at room temperature to study the mass loss with different n‐HA contents. All the preliminary results suggested that n‐HA/unsaturated poly(ester‐amide) nanocomposites might be potentially used as a new type of bone fixation material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Calcium polyphosphate fibers/unsaturated poly(ester‐amide) composites for bone‐fixation materials

A new type of unsaturated poly(ester‐amide) viz maleic anhydride‐phthalic anhydride‐propylene glycol‐neopentylene glycol‐glycin copolymer was prepared by melt polycondensation and characterized after sealed end with cyclohexanol. Mechanical strength of the crosslinked unsaturated poly(ester‐amide) with different heat‐treatment conditions was measured. Calcium polyphosphate fibers (CPPF) were used to boost up the new unsaturated poly(ester‐amide), mechanical strength, degradation, and hydrolysis behavior of CPPF/unsaturated poly(ester‐amide) composites with different CPPF content were measured. All the preliminary results suggested that the CPPF/unsaturated poly(ester‐amide) composites might be potentially used as a new type of bone‐fixation material. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Injection Molding Micro‐ and Nanostructures in Thermoplastic Elastomers

Flexible polymers such as poly dimethyl siloxane (PDMS) can be patterned at the micro‐ and nanoscale by casting, for a variety of applications. This replication‐based fabrication process is relatively cheap and fast, yet injection molding offers an even faster and cheaper alternative to PDMS casting, provided thermoplastic polymers with similar mechanical properties can be used. In this paper, a thermoplastic polyurethane is evaluated for its patterning ability with an aim to forming the type of flexible structures used to measure and modulate the contractile forces of cells in tissue engineering experiments. The successful replication of grating structures is demonstrated with feature sizes as low as 100 nm and an analysis of certain processing conditions that facilitate and enhance the accuracy of this replication is presented. The results are benchmarked against an optical storage media grade polycarbonate.

     

Synthesis and characterization of Sm(III)–hyperbranched poly(ester‐amide) complex

A novel Sm(III)–hyperbranched poly(ester‐amide) complex (Sm(III)–HBPEA) was synthesized, and characterized using Fourier transform infrared, ¹³C NMR and fluorescence spectroscopy and thermogravimetric analysis. Under the conditions used, HBPEA chelates to Sm³⁺ ions mainly via oxygen and nitrogen atoms of functional groups on the HBPEA chain. Modes of bonding of carboxyl groups, terminal hydroxyl groups and amide carbonyl structures may play the most important role in the coordination interaction. On excitation with UV light, the complex exhibits characteristic emission of both HBPEA and Sm³⁺. The presence of Sm³⁺ ions slightly accelerates HBPEA decomposition. Copyright © 2010 Society of Chemical Industry     

Radiopaque,barium sulfate‐filled biomedical compounds of a poly(ether‐block‐amide) copolymer

Various radiopaque compounds of a poly (ether‐block‐amide) copolymer resin filled with fine barium sulfate particles were prepared by melt mixing. Material properties of the filled compounds were investigated using various material characterization techniques, including thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic rheometry, uniaxial tensile test, and dynamic mechanical thermal analysis (DMTA). The effects of the filler and its concentration on the measured material properties are evaluated. It has been found that in addition to its well‐known X‐ray radiopacity, the filler is quite effective in reinforcing some mechanical properties of the copolymer, including modulus of elasticity and yield strength. More interestingly, it has been observed that at low loading concentrations near 10 wt %, the filler may also act as a rigid, inorganic toughener for the copolymer by improving the postyield material extensibility of strain hardening against ultimate material fracture. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Mesophase Structure‐Enabled Electrostrictive Property in Nylon‐12‐Based Poly(ether‐block‐amide) Copolymers

To search for alternative electrostrictive polymers and to understand the underlying mechanism, the structure‐ferroelectric/electrostrictive property relationship for nylon‐12‐based poly(ether‐b‐amide) multiblock copolymers (PEBAX) is investigated. Two PEBAX samples are studied, namely, P6333 and P7033 with 37 and 25 mol.% of soft poly(tetramethylene oxide) (PTMO) blocks, respectively. In both samples, poorly hydrogen‐bonded mesophase facilitates electric field‐induced ferroelectric switching. Meanwhile, the longitudinal electrostrictive strain (S₁)–electric field (E) loops are obtained at 2 Hz. Different from conventional poly(vinylidene fluoride‐co‐trifluoroethylene) [P(VDF‐TrFE)]‐based terpolymers, uniaxially stretched nylon‐12‐based PEBAX samples exhibit negative S₁, that is, shrinking rather than elongation in the longitudinal direction. This is attributed to the unique conformation transformation of nylon‐12 crystals during ferroelectric switching. Namely, at a zero electric field, crystalline nylon‐12 chains adopt a more or less antiparallel arrangement of amide groups. Upon high‐field poling, ferroelectric domains are enforced with more twisted chains adopting a parallel arrangement of amide groups. Meanwhile, extensional S₁ is observed for P6333 at electric fields above 150 MV m^?1. This is attributed to the elongation of the amorphous phases (i.e., amorphous nylon‐12 and PTMO). Therefore, competition between shrinking S₁ from mesomorphic nylon‐12 crystals (i.e., nanoactuation) and elongational S₁ from amorphous phases determines the ultimate electrostriction behavior in stretched PEBAX films.     

Toughening of poly(propylene carbonate) by hyperbranched poly(ester‐amide) via hydrogen bonding interaction

Poly(propylene carbonate) (PPC) is a biodegradable alternative copolymer of propylene oxide and carbon dioxide. As an amorphous polymer with lower glass transition temperature around 35 °C, PPC shows poor mechanical performance in that it becomes brittle below 20 °C and its dimensional stability deteriorates above 40 °C; thus toughening of PPC is urgently needed. Here we describe a biodegradable hyperbranched poly(ester‐amide) (HBP) that is suitable for this purpose. Compared with pure PPC, the PPC/HBP blend with 2.5 wt% HBP loading showed a 51 °C increase in thermal decomposition temperature and a 100% increase in elongation at break, whilst the corresponding tensile strength remained as high as 45 MPa and tensile modulus showed no obvious decrease. Crazing as well as cavitation was observed in the scanning electron microscopy images of the blends, which provided good evidence for the toughening mechanism of PPC. The intermolecular hydrogen bonding interaction confirmed by Fourier transform infrared spectral analysis proved to be the reason for the toughening phenomenon. Copyright © 2011 Society of Chemical Industry     

Compatibility,crystallinity and mechanical properties of poly(lactic acid)‐poly(ether‐block‐amide) based copper nanocomposites

Binary and ternary composites of poly(lactic acid) (PLA), poly(ether‐block‐amide) (PEBAX) and copper nanoparticles were prepared by melt blending in an internal mixer. Compatibility and molecular interactions between the three components of the nanocomposites were evaluated using scanning electron microscopy and Fourier transform infrared spectroscopy. It was found that the carbonyl groups of the PLA and copper nanoparticles interact. Also, PLA and PEBAX are compatible and develop molecular interactions between the C=O of PLA and the C=O and NH of PEBAX, forming dipole–dipole bonds and hydrogen bonds. The compatibility and molecular interaction between PLA and PEBAX are reduced by copper nanoparticles. The reduction of compatibility between PLA and PEBAX produced a lower storage modulus and lower strain at break in the ternary systems than in the blend PLA‐PEBAX. Copper nanoparticles enhanced the crystallinity of PLA. PLA responded more strongly to the nucleating effect of copper when PEBAX was added indicating a synergistic effect. The strain at break of PLA was enhanced by the addition of PEBAX but was severely reduced by the presence of nanoparticles. © 2020 Society of Chemical Industry     

Temperature influence on the behavior of polysulfone‐b‐poly(alkylene oxide)‐b‐poly(dimethylsiloxane) triblock copolymers in a selective solvent

Triblock copolymers containing polysulfone, poly(alkylene oxide), and poly(dimethylsiloxane) segments were obtained by addition of preformed α,ω‐bis(hydrogensilyl) poly(dimethylsiloxane) oligomers to alyl end‐capped poly(alkylene oxide)‐b‐polysulfone. Viscometric and UV absorption measurements were carried out in dilute 1,2‐dichlorethane solutions, in the temperature range of 20–75°C. The specific interactions exhibited by the block copolymers in a selective solvent are influenced by the copolymer composition and temperature. The results point to a conformational transition phenomenon, located around 55°C, which is attributed to the transition from a segregated to a pseudo‐Gaussian conformation through a compressed‐segregated conformation. POLYM. ENG. SCI., 57:114–118, 2017. © 2016 Society of Plastics Engineers     

Thermal properties and dielectric relaxation of a multi‐component poly(ether‐co‐amide) based on polyamide‐12

DSC, dielectric relaxation and dynamic mechanical thermal analysis (DMTA) were carried out on two multi‐component poly(ether‐co‐amide) samples having different weight ratios of polyamide prepared by condensation polymerization with 12‐aminododecanoic acid, adipic acid and polyetherdiamine consisting of poly(tetramethylene oxide) and poly(propylene oxide). The melting temperature was lowered by an increase in the weight ratio of the polyamide segment. Three relaxation modes, α′, α_s and β, were found from dielectric relaxation measurements in different temperature ranges. The high temperature relaxation mode, α′, has a large dielectric constant, which disappears at the melting temperature of the polyamide crystal in the sample. The relaxation times for the segmental motion, α_s, were different for the samples, which is attributed to the difference in the composition of the uncrystallized polyamide segments in the amorphous domain. The glass transition temperature estimated from DMTA is located between those of constituting polymers. On the other hand, the activation energy of β‐mode observed at low temperatures is the same for samples with different polyamide ratios, which is attributed to the local motion of the polyether segments. The uncrystallized polyamide segments are miscible with the polyether segments, which results in a lowering of the glass transition temperature of the amorphous domain and enlarges the temperature range of the rubber state of the copolymer due to the high melting temperature of the polyamide segments. © 2016 Society of Chemical Industry     

Synthesis and characterization of poly(ester‐ether‐imide)s derived from 5‐(4‐trimellitimidophenoxy)‐1‐trimellitimido naphthalene

A series of novel aromatic poly(ester‐ether‐imide)s with inherent viscosity values of 0.44–0.74 dL g^?1 were prepared by the diphenylchlorophosphate‐activated direct polycondensation of an imide ring‐containing diacid namely 5‐(4‐trimellitimidophenoxy)‐1‐trimellitimido naphthalene ( 1 ) with various aromatic dihydroxy compounds in the presence of pyridine and lithium chloride. Owing to comparison of the characterization data, an ester‐containing model compound ( 2 ) was also synthesized by the reaction of 1 with phenol. The model compound 2 and the resulted polymers were fully characterized by FT‐IR and NMR spectroscopy. The ultraviolet λ_max values of the poly(ester‐ether‐imide)s were also determined. The resulting polymers exhibited an excellent organosolubility in a variety of high polar solvents such as N,N‐dimethylacetamide, N,N‐dimethylformamide, dimethyl sulfoxide, and N‐methyl‐2‐pyrrolidone. They were soluble even in common less polar organic solvents such as pyridine, m‐cresol, and tetrahydrofuran on heating. Crystallinity of the polymers was estimated by means of wide‐angle X‐ray diffraction. The resulted polymers exhibited nearly an amorphous nature. From differential scanning calorimetry thermograms, the polymers showed glass‐transition temperatures between 221 and 245°C. Thermal behaviors of the obtained polymers were characterized by thermogravimetric analysis, and the 10% weight loss temperatures of the poly(ester‐ether‐imide)s were found to be over 410°C in nitrogen. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Drug delivery system based on poly(ether‐block‐amide) and acrylic acid for controlled release of vancomycin

Poly(ether‐block‐amide) (PEBA) films were grafted with acrylic acid (AAc) by gamma radiation, using the oxidative pre‐irradiation technique. The effect of dose, monomer concentration, temperature, and reaction time on the graft percentage of AAc onto PEBA was studied. The modified material PEBA‐g‐AAc was characterized by Fourier infrared spectroscopy (FTIR), scanning electron microscopy, and water contact angle. It was found that PEBA films did not suffer degradation at low doses (<30 kGy) during the grafting process. Additionally, PEBA‐g‐AAc was proved as drug delivery system using vancomycin as drug model. The PEBA‐g‐AAc with 39 and 98% of AAc loaded 63 and 98 mg g^?1, respectively. The release profiles showed a sustained delivery by 48 h with a partial retention of drug, which depends of grafting percentage. The microbiological tests showed that PEBA‐g‐AAc was able to inhibit the growing of Staphylococcus aureus in three consecutive challenges. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45745.