Terpolymer Poly Research Articles

Synthesis of Poly(L-lactide)-poly(ε-caprolactone)-poly(ethylene glycol) Terpolymer Grafted onto Partially Oxidized Carbon Nanotube Nanocomposites for Drug Delivery.

Nanocomposites prepared with a terpolymer of poly(L-lactide) (PLLA)-poly(ε-caprolactone) (PCL)-poly(ethylene glycol) (PEG) and partially oxidized carbon nanotubes (CNTspo) were synthesized and characterized to evaluate their ability to act as an effective nanocarrier of the anticancer drug methotrexate. The homopolymers of PLLA and PCL were synthesized through ring-opening polymerization (ROP) and characterized through gel permeation chromatography (GPC). The PLLA-PCL-PEG terpolymers were synthesized through a four-step chemical route using oxalyl chloride as a linker agent and analyzed with 1H-NMR, 13C-NMR, and FTIR spectroscopies. Additionally, the nanocomposites were characterized through FTIR, and X-ray photoelectron spectroscopy (XPS), as well as the differential scanning calorimetry (DSC) technique. XPS analysis revealed that PLLA-PCL-PEG terpolymer chains are grafted onto CNTspo. Moreover, evaluations through FTIR and DSC strongly suggest that the PCL-rich domains are preferentially oriented toward CNTspo. The release tests exhibited a "burst effect" profile, which was more evident in the terpolymers than in the nanocomposites. Five models were used to assess methotrexate's in vitro release. For the nanocomposites, the best fit to the experimental data was obtained using the first-order model, whereas the results obtained from the Korsmeyer-Peppas model indicated that Fickian diffusion drives methotrexate's release.

Influence of HFP monomer segments on the crystal structure and electromechanical responses of a P(VDF-TrFE-CFE-HFP) tetrapolymer

The electromechanical properties of PVDF-based polymers, namely converting electrical into mechanical energy, are mainly decided by the crystal structure and domain size of the target product. Thus, we prepare the poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)), its terpolymer poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)), and tetrapolymer poly(vinylidene fluoride-trifluoroethylene-chlorofluoroethylene -hexafluoropropylene) (P(VDF-TrFE-CFE-HFP)) films for comparison, respectively, where the role of the introduction of third and fourth monomers in the electromechanical properties of P(VDF-TrFE) is completely disclosed. Because of introducing CFE and HFP monomers, P(VDF-TrFE) with the ferroelectricity has converted into the relaxor ferroelectric P(VDF-TrFE-CFE-HFP) with a slimmer P-E loop while maintaining good maximum polarization (Pm). Since the nano ferroelectric domains in the relaxor ferroelectric material are easy to reverse along the polarizing electric field, The P(VDF-TrFE-CFE-HFP) sample achieved a dielectric constant (εr) of ∼29 and a strain in the thickness direction (S33) of ∼ -5%, respectively, while the εr and S33 of P(VDF-TrFE) sample are ∼11 and ∼-0.8 %, respectively. This research indicates the availability of the third and fourth monomers for improving the electromechanical effect of such electrostrictive polymers, having wide applications in flexible actuators, transformers, sensors, and so forth.

Giant electrocaloric effect and breakdown field strength in ferroelectric terpolymer nanocomposites by morphologically diverse nanostructures

Electrocaloric cooling is a method for flexible electronics and compact chips with a promising ability to subvert traditional vapor compression refrigeration technology. Nevertheless, most reported EC materials exhibit relatively low adiabatic temperature (ΔT) and low breakdown field strength (Eb) at room temperature, limiting their further applications. Here, we develop a ferroelectric nanocomposite, composed of relaxor terpolymer poly(vinylidene fluoride-trifluoroethylen-chlorofluoroethylene) (PVTC), ceramic nanofillers [0.68(BaZr0.2Ti0.8O3)-0.32(Ba0.7Ca0.3TiO3)] (BCZT), boron nitride nanosheets (BNNSs), and BiFeO3 nanofibers (BFO NFs) with different morphologies and vary components ratios. The most optimal 12BBBP nanocomposite demonstrates gigantic ECE values including an isothermal entropy change (ΔS) of 94.5 J·kg−1·K−1 and a ΔT of 13.5 K under 220 MV/m electric field at 303 K, ΔS and ΔT are 3.5 times and 2.2 times larger than PVTC under 100 MV/m. It also exhibits an excellent Eb with a value of 290 MV/m. The phase-field simulation is used to simulate Eb behavior of nanocomposites with fillers of different nano-morphologies under an electrostatic field. Simultaneously, the interfacial coupling and ferroelectric domain structures are also simulated based on the time-dependent Landau-Ginzburg-Devonshire (TLGD) theory through finite element analysis (FEA) to present a better explanation for ECE performance. The experimental and simulation results simultaneously denote the ferroelectric nanocomposite possesses outstanding ECE and high Eb performance, laying foundation for the ferroelectrics in fields of flexible electronics and compact chip cooling. Coupled with the facile processability of terpolymer and lead-free nature of electroactive ceramics, this work paves a new way to develop a scalable, environmentally friendly and high-performance EC materials for next generation of refrigeration.

Fabrication of pH-responsive poly(vinyl alcohol)-based microfibers crosslinked with copolymers containing benzoxaborole and carboxy groups

Water-insoluble pH-responsive poly (vinyl alcohol) (PVA)-based microfibers were prepared using terpolymer of poly ([2-(methacryloyloxy)ethyl]trimethylammonium chloride (METAC)-co-methacrylic acid (MAAc)-co-5-methacrylamido-1,2-benzoxaborole (MAAmBO)) (TP) containing a quaternary ammonium cation, as well as carboxy and benzoxaborole groups. The surface of the microfibers could be positively charged by the permanent positive charge of the METAC units owing to the presence of the quaternary ammonium cation. The MAAc units formed a covalent bond with the hydroxy group of the vinyl alcohol unit by thermal treatment at 135 °C for 24 h, and the MAAmBO units formed a dynamic covalent bond with the diol group in PVA. After thermal crosslinking for 24 h, the PVA/TP microfibers exhibited almost 100% of the residual weight after immersion in water at 80 °C for 30 min. The diameters of the dried PVA/TP_25 wt% fibers were 21.4 ± 3.9 μm, and the swelling ratio was 1.65 ± 0.16 after immersing in water for 24 h. All microfibers showed a low degree of hemolysis (<5%). The PVA/TP_25 wt% fibers were strongly dyed with anionic acid red 1 (AR1) molecules at pH 3 and with cationic methylene blue (MB) molecules at pH 12, since the balance of the surface charge depend on the solution pH. These microfibers could be bundled and twisted to improve their mechanical properties; the required fracture energy after twisting was 2.30 ± 0.91 times higher than that before twisting.

Relaxor-antiferroelectric hybrids for pyroelectric energy conversion from low-grade heat using flexible PVDF-TrFE-CTFE-NaNbO3 nanocomposite films

Nowadays, researchers focus more on developing smart materials that respond to different stimuli for harvesting energy output. In this paper, the pyroelectric energy harvesting capabilities of smart terpolymer poly(vinylidene-fluoride-trifluoroethylene-chlorotrifluoroethylene) [PVDF-TrFE-CTFE]-based nanocomposites have been investigated. Sodium niobate (NaNbO3) from the perovskite family is selected as the filler. The Sol-gel method is used to synthesise NaNbO3 nanoparticles, and solvent-cast films for different weight fractions (0–20%) of fillers have been fabricated. Structural, morphological, and dielectric properties of the polymer nanocomposite samples were done at room temperature. The ferroelectric properties of the terpolymer is improved with filler addition. The thermal stability of composite films was confirmed using differential scanning calorimetric (DSC) studies. The thermodynamic Olsen cycle was applied to nanocomposites for calculating the harvested energy output. Maximum energy density is obtained for higher filler loading (20 wt % sodium niobate). The operating temperatures were selected at 303 K and 333 K with an applied field of 130 kV/cm. The results show that including NaNbO3 in the relaxor terpolymer matrix considerably enhances the energy harvesting density of the nanocomposites, indicating that they are promising materials for designing thermally stable energy harvesting systems.

Exploring the Effect of Drug Loading on the Biological Fate of Polymer-Coated Solid Nanoparticles

Polymer-coated inorganic nanoparticles (NPs) have attracted great attention in drug delivery fields due to their unique magnetic, optical, and thermal properties. Recent studies have shown that the surface physicochemical properties of these NPs, including the size, shape, shell hydration, protein corona, and so forth, affect their biological fate. However, there has been less attention on the effect of the drug loading amount on the biological activity of inorganic NPs. Here, we used upconverting NPs (UCNPs) as an inorganic nanocarrier model, coated them with a triblock terpolymer poly(poly(ethylene glycol) methyl ether methacrylate)-block-polymethacrylic acid-block-ethylene glycol methacrylate phosphate (PPEGMEMA-b-PMAA-b-PEGMP), and loaded them with different amounts of anticancer drug doxorubicin (DOX) by electrostatic interactions. Our results show that the UCNPs with the lowest DOX loading amount (1.32%) have the best biological behavior. We find that the effect of DOX loading on the biological behavior of UCNPs is dominated by polymer shell hydration and the protein corona. The lowest drug-loading UCNPs are more hydrated and have more albumin coronas around, which leads to an increasing effect on the association with cancer cells and drug accumulation in the mouse tumor area. Our findings highlight the importance of optimizing the drug loading amounts in polymer-coated inorganic drug delivery systems as the amount and type of drug will alter the physical properties of the polymer shell.

Investigation of Poly(MM-EM-BM) as Nanosealing Materials in Oil-Based Drilling Fluids: Synthesis and Evaluation.

Nanosealing technology has become the key to overcoming the wellbore instability problem in deep and ultradeep shale formations. In this Article, the terpolymer poly(MM-EM-BM) was synthesized from methyl methacrylate, ethyl methacrylate, and butyl methacrylate by a Michael addition reaction. The poly(MM-EM-BM) nanoparticles were investigated by Fourier transform infrared spectroscopy, laser scattering analysis, and thermogravimetric analysis. The results imply that the particle size range of poly(MM-EM-BM) is between 33.90 and 135.62 nm and the average diameter is about 85.95 nm at room temperature, which can maintain excellent stability at 382.75 °C. The effects of poly(MM-EM-BM) on the properties of oil-based drilling fluids (OBDFs) were ascertained through experiments on the rheological performance, electrical stability, and high-temperature and high-pressure (HTHP) filtration loss. The results suggested that when the amount of added poly(MM-EM-BM) increases, the apparent viscosity, plastic viscosity, dynamic shear force, and demulsification voltage of the drilling fluids will increase correspondingly; in contrast, the HTHP filtration loss gradually decreased. When poly(MM-EM-BM) is added at 0.75%, the kinetic-to-plastic ratio of the drilling fluids is 0.24 and the filtration loss is 0.6 mL, showing excellent overall performance. The drilling fluids have a good rock-carrying ability and water loss wall-building property. The sealing performance and mechanism of poly(MM-EM-BM) were researched by the method of a sealing performance test under high temperature. The results indicated that the more poly(MM-EM-BM) used, the higher the sealing efficiency of the mud cake and the core as the sealing medium. When poly(MM-EM-BM) was added at 0.75%, the sealing rates of the mud cake and the core as the sealing medium reached the maximum sealing rates of 40.30% and 91.48%, respectively. When poly(MM-EM-BM) enters the core nanopore joint for a certain distance under formation pressure, a tight sealing layer will be formed to effectively prevent the entry of filtrate. Poly(MM-EM-BM) as a potential oil-based nanosealing agent is expected to solve the problem caused by wellbore instability in shale horizontal wells.

Inside Block Copolymer Micelles-Tracing Interfacial Influences on Crosslinking Efficiency in Nanoscale Confined Spaces.

Recently, several studies have demonstrated the excellent capabilities of tip-enhanced Raman spectroscopyfor in-depth investigations of structural properties of matter with unprecedented resolution and chemical specificity. These capabilities are utilized here to study the internal structure of core-crosslinked micelles, which are formed by self-assembly of the diblock terpolymer poly(ethylene oxide)-block-poly(furfuryl glycidylether-co-tert-butylglycidyl ether). Supplementing force-volume atomic force microscopy experiments address additionally the nanomechanical properties. Particularly, TERS enables investigating the underlying principles influencing the homogeneity and efficiency of the Diels-Alder core-crosslinking process in the confined hydrophobic core. While the central core region is homogenously crosslinked, a breakdown of the crosslinking reaction is observed in the core-corona interfacial region. The results corroborate that a strong crosslinking efficiency is directly correlated to the formation of a mixed zone of the glycidyl ether and PEO corona blocks reaching ≈5 nm into the core region. Concomitantly a strong exclusion of the encapsulated bismaleimide crosslinker from the interfacial region is observed. It is conceivable that a changed structure, chemical composition and altered nanomechanical properties of this interfacial region may also influence the crosslinking efficiency across the entire core region by a modification of the solubility of the crosslinker in the interfacial core-corona region.

Effects of ionic strength and ion-specificity on the interface behavior of PDMAEMA-b-PLMA-b-POEGMA triblock terpolymer

Ion-specificity on the stretching degree of diblock copolymers containing poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) at the air/water interface has previously been proved to be inconsistent with the Hofmeister series. In this work, the aggregation behavior of an amphiphilic linear triblock terpolymer poly[2-(dimethylamino)ethyl methacrylate]-block-poly(lauryl methacrylate)-block-poly[oligo(ethylene glycol) methacrylate] (PDMAEMA-b-PLMA-b-POEGMA) on the aqueous subphase with different ionic strengths and ion species (salts) was studied, and the morphologies of its Langmuir−Blodgett (LB) films were explored. At the air/water interface, the terpolymer tends to form surface micelles composed of hydrophobic PLMA cores and mixed hydrophilic coronas of PDMAEMA and POEGMA. Under acidic conditions with low ionic strength, the hydrophilic PDMAEMA blocks of the terpolymer are almost completely electrostatic screened. With the increase of subphase ionic strength, the surface pressure−molecular area isotherms of the terpolymer monolayers at the air/water interface gradually move to large areas due to the increased interfacial stretching degree of POEGMA blocks resulting from the increased salting-out effect and interfacial steric hindrance of PDMAEMA blocks. The hysteresis degrees of the terpolymer monolayers in the presence of salts in the subphase are larger than that in the absence of salt. Under alkaline conditions, the isotherms of the terpolymer monolayers move to large areas with the increase of salt concentration because the introduction of salt makes the hydrophilic blocks more stretched. The experimental results show that the relationship between their interfacial stretching degrees of two kinds of hydrophilic blocks and the types of salt in solution is inconsistent with the Hofmeister series. This may be due to tethering of the corona chains on the hydrophobic core and the configurational constrains (crowding phenomena) induced within the mixed micelle corona. Under different subphase conditions, the LB films of the terpolymer show isolated circular micelles due to the mutual repulsions of the long hydrophilic PDMAEMA and POEGMA blocks.

Electrostatic Adhesion Clutch with Superhigh Force Density Achieved by MXene-Poly(Vinylidene Fluoride-Trifluoroethylene-Chlorotrifluoroethylene) Composites.

Electrostatic adhesion (EA) clutches are widely applied in robots, wearable devices, and virtual reality, due to their compliance, lightweight, ultrathin profile, and low power consumption. Higher force density has been constantly perpetuated in the past decades since EA was initially proposed. In this study, by composing terpolymer poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) [P(VDF-TrFE-CTFE)] and two-dimensional Ti3C2Tx nanosheets (MXene), nanocomposite films with high dielectric constant ( > 2300) and low loss tangent are achieved. The force representative index (the relative dielectric constant times the square of breakdown electric field) is enhanced by 5.91 times due to the charge accumulation at matrix-filler interfaces. Superhigh shear stress (85.61 N cm-2) is generated, 408% higher than the previous maximum value. One of the EA clutches fabricated in this study is only 160 μm thin and 0.4 g heavy. Owing to the low current (<1 μA), the power consumption is <60 mW/cm2. It can hold a 2.5 kg weight by only 0.32 cm2 area and support an adult (45 kg) (Clinical Trial Registration number: 20210090). With this technology, a dexterous robotic hand is displayed to grasp and release a ball, showing extensive applications of this technique.

Aggregation behavior of triblock terpolymer poly[n‐butyl acrylate‐block‐N‐isopropylacrylamide‐block‐2‐(dimethylamino)ethyl acrylate] at the air/water interface

AbstractLangmuir film balance technique was used to study the subphase pH and temperature effects on the aggregation behavior of a dual‐responsive triblock terpolymer poly[n‐butyl acrylate‐block‐N‐isopropylacrylamide‐block‐2‐(dimethylamino)ethyl acrylate] (PnBA‐b‐PNIPAM‐b‐PDMAEA) at the air/water interface. Atomic force microscopy was used to observe the morphologies of its Langmuir–Blodgett (LB) films. At the interface, the terpolymer tends to form isolated circular micelles composed of hydrophobic PnBA cores and hydrophilic PNIPAM‐PDMAEA coronas. The limiting areas in the surface pressure–molecular area isotherms under acidic and alkaline conditions are larger than that under neutral conditions due to the larger interfacial stretching degrees of PNIPAM blocks, which results from the strong electrostatic repulsions of the fully protonated PDMAEA blocks underwater in the acidic case. In our minds, the hysteresis degrees of the compression−expansion cycles under different subphase pH conditions should mainly depend on the initial stretching degrees of the hydrophilic blocks. Under acidic conditions, the isotherms shift toward small areas with the increase of temperature due to the increased solubility of PNIPAM blocks. However, under alkaline conditions, the isotherms significantly exhibit the lower critical solution temperature behavior of PNIPAM blocks, which is a good example to build up the relationship between the interfacial and solution properties of block copolymers.

Assembly of skin substitute by cross-linking natural biomaterials on synthetic biodegradable porous mat for critical-size full-thickness burn wound regeneration

Human skin architecture comprises several interpenetrating macromolecules seen as organized extracellular matrix (ECM). For regeneration of critical-size acute and chronic wounds, substituting the damaged tissue with artificially assembled biomolecules offer an interactive milieu. This study reports development and preclinical evaluation of a biodegradable and immuno-compatible scaffold for regeneration of critical-size (4 × 4 cm2) full-thickness rabbit burn wounds. The designed wound care product comprises synthetic terpolymer poly(L-Lactide-co-Glycolide-co-Caprolactone) (PLGC), human clinical-grade fibrin (FIB), and hyaluronic acid (HA), termed as PLGCFIBHA. Here, clotting of fibrinogen concentrate (FC) with excess thrombin in the scaffold create an interpenetrating FIB network harnessed with adhesive molecules like fibronectin and laminin present in FC with exogenous HA to produce ECM-like milieu on porous PLGC. Penetrating into porous PLGCFIBHA, long term study showed a regulated fibroblast growth resulting in non-fibrotic dermal-like tissue in vitro. The freeze-dried PLGCFIBHA with residual thrombin facilitated suture-less, hemostatic matrix adhesion to the wound bed in vivo. By 28 d, mature and scar-less epidermis-dermis formation with skin appendages was evident in the PLGCFIBHA-treated wound area. Both negative (untreated/sham) and positive (commercial matrix-treated) control wounds showed incomplete regeneration. The PLGCFIBHA-treated wounds were comparable to native skin by 56 d. These regenerative outcomes upon single application of PLGCFIBHA confirms its potential translational value for wound care.

Engineered nanogels shape templated by closo-dodecaborate nano-ion and dictated by chemical crosslinking for efficient boron delivery

The shape of nanoparticles is a key factor for efficient delivery of a cargo to cells. We prepared nanogels of controllable shape suitable for boron delivery from cationic triblock terpolymers poly(ethylene oxide)-b-poly(2-(N, N, N’, N’-tetramethyl guanidium) ethyl acrylate)-b-poly(2-(dimethylamino)ethyl acrylate), PEO-b-PGEA-b-PDMAEA, and closo-dodecaborate nano-ions. The physical crosslinking based on ion pairing of closo-dodecaborate with PGEA blocks led to preassembled nanogels of spherical and wormlike shape. PDMAEA blocks were later chemically crosslinked with 1,2-bis(2-iodoethoxy)ethane, BIEE, to maximize the boron loadings and the nanogels stability. Depending on the blocks lengths, a shape transition was observed after the chemical crosslinking. As confirmed by flow cytometry and confocal microscopy in cervical carcinoma cell lines in vitro, the wormlike chemically crosslinked nanogels were internalized the most efficiently.

Augmentation of dye-sensitized solar cell photovoltaic conversion efficiency via incorporation of terpolymer Poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate) based gel polymer electrolytes

A dye-sensitized solar cell (DSSC) is the alternative photovoltaic technology for the replacement of the standard photovoltaic liquid electrolyte-dependent cell. Gel polymer electrolyte (GPE) was used in this research to replace the volatile liquid electrolyte. This GPE has been developed using terpolymer type Poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate) P(VB-co-VA-co-VAc), iodine (I2), sodium iodide (NaI), and ethanol. The findings from X-ray diffraction (XRD) showed the effect of NaI on the crystalline content of the electrolyte systems. Samples showed higher conductivity with a lower degree of crystallinity. Differential scanning calorimetry (DSC) analysis revealed the slight decrease in melting temperature (Tm) upon addition of NaI salts. The thermogravimetric analysis (TGA) showed that GPE ′s thermal stability decreases as NaI salt content increases. Fourier-transform infrared (FTIR) results indicated that P(VB-co-VA-co-VAc) interacted with NaI. The highest room temperature ionic conductivity of 3.22 × 10−3 S cm−1 by the sample with 30 wt % NaI. Temperature-dependent findings showed that all GPE samples adhere to the Arrhenius equation in the temperature range from 303 K to 373K and found the lowest activation energy obtained by the sample with 30 wt % NaI as 0.066 eV. Dielectric and modulus properties of all samples have been studied. DSSC fabricated using the electrolyte containing 30 wt% NaI has achieved the highest conversion efficiency of 4.01% with maximum JSC value of 12.52 mA cm−2, VOC of 0.61 V, and fill factor (FF) of 51.8%.

Ordered Mesoporous Microcapsules from Double Emulsion Confined Block Copolymer Self-Assembly.

Polymeric microcapsules with shells containing homogeneous pores with uniform diameter on the nanometer scale are reported. The mesoporous microcapsules are obtained from confined self-assembly of amphiphilic block copolymers with a selective porogen in the shell of water-in-oil-in-water double emulsion drops. The use of double emulsion drops as a liquid template enables the formation of homogeneous capsules of 100s of microns in diameter, with aqueous cores encapsulated in a shell membrane with a tunable thickness of 100s of nanometers to 10s of microns. Microcapsules with shells that exhibit an ordered gyroidal morphology and three-dimensionally connected mesopores are obtained from the triblock terpolymer poly(isoprene)-block-poly(styrene)-block-poly(4-vinylpyridine) coassembled with pentadecylphenol as a porogen. The bicontinuous shell morphology yields nanoporous paths connecting the inside to the outside of the microcapsule after porogen removal; by contrast, one-dimensional hexagonally packed cylindrical pores, obtained from a traditional diblock copolymer system with parallel alignment to the surface, would block transport through the shell. To enable the mesoporous microcapsules to withstand harsh conditions, such as exposure to organic solvents, without rupture of the shell, we develop a cross-linking method of the nanostructured triblock terpolymer shell after its self-assembly. The microcapsules exhibit pH-responsive permeability to polymeric solutes, demonstrating their potential as a filtration medium for actively tunable macromolecular separation and purification. Furthermore, we report a tunable dual-phase separation method to fabricate microcapsules with hierarchically porous shells that exhibit ordered mesoporous membrane walls within sponge-like micron-sized macropores to further control shell permeability.

Synthesis of Novel Type Terpolymer Poly(Eugenol-co-methylmethacrylate-co-hydroxyethylmethacrylate) Using Photopolymerization Method: Characterization and Investigation of Thermal Properties

In this study, it has been demonstrated that Poly(Eugenol-co-methylmethacrylate-co-hydroxyethylmethacrylate) terpolymers were successfully synthesized by using photopolymerization method. This synthesis was carried out in one step at ambient temperature, benzophenone and triethyl amine was used as the photoinitiator and hydrogen donor, respectively. Methyl methacrylate (MMA), 2-Hydroxyethyl methacrylate (HEMA) and Eugenol (Eg) were used as monomer in photopolymerization. Terpolymers are named as F-BAP1, F-BAP2, F-BAP3 and F-BAP4 according to the ratio of monomers used. Structural characterization and thermal properties of the synthesized terpolymers were carried out by FTIR (Fourier-transform infrared spectroscopy), 1H-NMR (Nuclear magnetic resonance spectroscopy), TG-DTG (Thermogravimetry-Differential Thermogravimetry) and DSC (Differential scanning calorimetry) methods. Characterization of molecular weight distributions were determined by viscometric method. SEM (Scanning electron microscope) was used for surface analysis. According to the data obtained from thermal analysis, two degradation steps are seen in thermograms of the terpolymers except FBAP-2. The maximum degradation temperature of F-BAP 2 is 422 oC, the first degradation temperature of the other terpolymers between 250-280 oC and the second one between 421-427 oC.

Thermomechanical analysis and pH-triggered elastic response of charge-balanced sulfonated poly(tertiary amine-methacrylate)-based terpolymer cryogels

pH-responsive terpolymer poly(hydroxyethyl methacrylate-2-acrylamido-2-methyl-propanosulfonic acid-diethylaminoethyl methacrylate) cryogels and hydrogels (named as CGs-PHA/Dm and HGs-PHA/Dm) were synthesized in ethanol-water mixture using different monomer feed compositions. By the combination of three monomers, an interesting system was designed with tunable pH/temperature responsiveness and elasticity. ATR-FTIR spectrums obtained after swelling swelling in pH buffer solution of 2.1 indicated –R2NH+ stretching of DEAEMA moities in terpolymer matrices. By incorporation of DEAEMA units with ionizable amino groups, terpolymer CGs-PHA/Dm and HGs-PHA/Dm gels exhibited pH-responsive swelling behavior. Inclusion of DEAEMA dramatically altered pH-responsiveness of terpolymers in simulated intestinal fluid at pH 6.6. Dependence of interaction parameter χon terpolymer volume fraction in gel ν2by a linear function and its enthalpic/entropic components with swelling pH were determined. At pH < 6.6, dependence of χ parameter on the swelling was evaluated as χ=1.097-2.965ν2, while at basic pH region, pH > 6.6, χ=0.576+0.459ν2. Both pH of swelling medium and the amount of DEAEMA in terpolymer composition affected the compression moduli of terpolymer gels. Flory-Rehner theory extended to correlate the compressive modulus with swelling pH and the dependence of the effective crosslink density νeon mol% DEAEMA was expressed in both acidic and basic conditions. pH-triggered swelling/shrinking of terpolymer gels were studied as reversible cycles in buffer solutions of pH 2.1 and 9.8. DEAEMA-rich terpolymer gels showed overshooting phenomena due to dynamic conformational changes of diethylaminoethyl units. Terpolymer cryogels exhibited much faster swelling kinetics than that of terpolymer hydrogels in simulated gastric fluid at pH 2.1. The values of diffusion coefficient seemed to be strongly dependent of terpolymer composition.

Heteronuclear, Monomer-Selective Zn/Y Catalyst Combines Copolymerization of Epoxides and CO2 with Group-Transfer Polymerization of Michael-Type Monomers.

Terpolymerizations of cyclohexene oxide (CHO), CO2, and the Michael-type monomer 2-vinylpyridine (2VP) are presented. The combination of two distinct polymerization mechanisms was enabled by the synthesis of a heterobifunctional complex (3). Its β-diiminate zinc moiety allows the ring-opening copolymerization of CHO and CO2, whereas the yttrium metallocene catalyzed the rare earth metal-mediated group-transfer polymerization of the polar vinyl monomer. Both units were connected via the CH-bond activation of a pyridyl-alkoxide linker. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) revealed the successful transfer of the linker to the end-group of the respective homopolymers poly(cyclohexene carbonate) (PCHC) and poly(2VP) (P2VP) being the prerequisite for copolymer formation. Aliquot gel-permeation chromatography (GPC) analysis and solubility behavior tests confirmed the P2VP-block(b)-PCHC terpolymer formation via two pathways, a sequential and a one-pot procedure. Furthermore, the versatility of the method was demonstrated by introducing 2-isopropenyl-2-oxazoline (IPOx) as the second Michael-type monomer that yielded the terpolymer poly(IPOx)-b-PCHC.

Surface Modification of PTLG Terpolymer Using PNIPAAm and Its Cell Adhesion/Detachment Behavior

AbstractNovel biodegradable terpolymer poly (1,3‐trimethylene carbonate‐b‐(l‐lactide‐r‐glycolide)) grafted with poly(N‐isopropylacrylamide) (PTLG‐PNIPAAm) is prepared by plasma‐induced polymerization. The experimental results show that PNIPAAm segments of samples have a dramatic effect on surface layer structure and cell behavior of PTLG‐PNIPAAm. The thickness of PNIPAAm layer on PTLG surface increases rapidly from 50 nm to 1 µm with the molecular weight of samples increasing. Cell toxicity analysis indicates that PTLG‐PNIPAAm possesses good cytocompatibility to human adipose‐derived stem cells (hADSCs). For cell adhesion and detachment process on modified surface, the “hook and loop” process is proposed to understand the cell adhesion on modified surface with coiled conformation PNIPAAm segments at 37 °C, and then the cell sheet detached from surface spontaneously due to the conformation of PNIPAAm segments extends below its lower critical solution temperature. The research demonstrates that with increasing thickness of the PNIPAAm layer on PTLG surface, the hADSCs with well cell viability presents rapider thermal‐responsive detachment behavior. Therefore, the surface modification of biodegradable PTLG with stimuli‐sensitive functional PNIPAAm is an efficacious route for further application in stem cell culture and tissue engineering stent.

Viscosifying a Noncovalently Joined Polymer Nanoparticle Solution upon Heating

We report the synthesis of a series of statistical terpolymer poly[(methyl methacrylate)-co-lauryl methacrylate-co-2-((3,5-bis(4-carbamoyl-3-(trifluoromethyl)phenoxy)benzyloxy)carbonylamino)ethyl m...