Range Of Polymer Concentrations Research Articles

Polymer Stability After Successive Mechanical-Degradation Events

Summary A key challenge in polymer-flood forecasting is the prediction of polymer stability far from the injector. Degradation may result from various mechanical-degradation events in surface facilities and at the wellbore interface, as well as possible oxidative degradation caused by the presence of oxygen and reduced transition metals. All these steps must be closely examined to minimize degradation and ensure propagation of a viscous polymer solution. In this paper, polymer solutions are pushed toward degradation rates that would be unacceptable for enhanced-oil-recovery applications to better understand the underlying physics. Multistep degradation events are induced in various geometries, such as capillaries, blenders, and porous media. For the geometries and range of polymer and salt concentrations investigated, degradation (as defined here) approaches an asymptotic value as the number of degrading events increases. An empirical normalization method is proposed, allowing superimposition of curves of viscosity loss vs. time across multiple possible geometries. The normalization procedure is applied to predict the extent of degradation during a field injection in which near-wellbore degradation occurs after degradation in surface facilities. We predict that degradation in the porous medium reaches a stable value after passing through approximately 6 mm of rock. Finally, degradation is proposed as a tool to probe the molecular-weight distribution and to narrow the polydispersity of polymers, which can be used for maximizing both viscosifying power and injectivity simultaneously.

Torque in Taylor–Couette flow of viscoelastic polymer solutions

When a polymer solution is sheared between concentric cylinders, with the inner rotating and the outer fixed, the torque on the inner cylinder is modified compared to a Newtonian fluid of the same viscosity revealing the different flow patterns that emerge above the linear stability threshold for circular Couette flow. Here, mixtures of relatively short and long linear polymers in dilute and semi-dilute concentrations were considered. Their shear viscosity and extensional relaxation time are quantified. The stability of the flow is monitored through torque measurements and flow visualisations for a constant rate of acceleration and deceleration of the inner cylinder in a wide range of polymer concentrations. The torque exhibits an hysteretic behaviour, typical of subcritical transition. For large concentrations, six different numbers of steady solitary pairs of vortices, called diwhirls, were observed depending on the deceleration rate and their torque contribution is reported.

Role of thermodynamic and kinetic interaction of poly(vinylidene fluoride) with various solvents for tuning phase inversion membranes

An extensive study of thermodynamics and kinetics of non‐solvent induced phase separation was carried out for poly(vinylidene fluoride)/solvent/water system for four different solvents. Literature available on semicrystalline polymers was mostly based on experimental cloud points, obtained to a narrow range of polymer concentration (<10 wt%), much less than the working range for membrane preparation (20–25 wt%). Aim of this work was to model the thermodynamic phase diagram using extended Flory–Huggins theory which was used as a tool, along with the kinetic data to obtain tailor‐made membranes with desired morphology and properties. Interaction parameters involving solvent, nonsolvent, and polymer played an important role to tune the porosity of the membrane. Thermodynamic calculation showed solvent N,N‐dimethyl acetamide resulted in the most porous membrane (permeability 5.4 × 10−11 m Pa−1 s−1) followed by N,N‐dimethyl formamide (permeability 4.2 × 10−11 m Pa−1 s−1), N‐methyl pyrrolidone (permeability 3.8 × 10−11 m Pa−1 s−1), and acetone (impermeable to water even at 1380 kPa), which was the densest one. Prepared membranes were characterized in terms of surface morphology, molecular weight cut‐off, tensile strength, pore volume distribution, crystallinity, and surface roughness, which were correlated to inferences based on thermodynamic and kinetic calculations. POLYM. ENG. SCI., 58:1062–1073, 2018. © 2017 Society of Plastics Engineers

Flow behaviours comparison of crude oil–polymer emulsions

ABSTRACTThe flow characteristics of crude oil–polymer (COPE) emulsions were investigated in terms of viscosity and shear stress. Two commonly used polymers in the enhanced oil recovery were employed. These two different polymers are Alcoflood and Xanthan gum. Rheostress RS100 was used in this study for measuring and analysing the experimental measurements. A cone and plate sensor of RS100 rheometer was utilised for this investigation. The experimental measurements of viscosity and shear stress of different COPE were examined over the shear rate range of 0.1–1000 s−1. The polymer concentration range of 500–104 ppm was examined and two crude oil concentrations of 25% and 75% by volume were tested. A detailed investigation of the flow behaviour of COPE in the presence of two different polymers was completed. The flow behaviour of all COPE exhibit non-Newtonian shear thinning behaviour that can be presented by the power-law model for crude oil-AF1235, however the other types of COPE can be predicted by the Casson model. For a low polymer concentration of 500 ppm, this investigation showed that the flow behaviour of Xanthan emulsions is slightly higher than the Alcoflood emulsions till a shear rate of 100 s−1. For the higher polymer concentrations, both polymer emulsions exhibited more or less similar flow behaviours till the beginning of the shear thickening for the AF1285 emulsions.

Rheological study on the thermoinduced gelation behavior of poly(N‐isopropylacrylamide‐co‐acrylic acid) microgel suspensions

ABSTRACTSubmicron‐sized thermoresponsive poly(N‐isopropylacrylamide‐co‐acrylic acid) microgels were synthesized by soap‐free emulsion polymerization. The physical state of the microgel suspensions, in a wide range of polymer concentrations (1.1–7.1 wt %), transformed from fluid to gel when the temperature was elevated across their volume phase transition temperature at pH = 3.0. Such thermoinduced gelation behavior was studied in detail by small‐deformation oscillatory rheological measurements within the linear viscoelastic region. It was found that the gelation temperature was strongly affected by the polymer concentration, decreasing as the polymer concentration increased. The gelation kinetics showed that the suspension gelled more quickly at either larger polymer concentration or higher isothermal heating temperature. In an isothermal frequency sweep for the as‐formed gels, both storage and loss moduli, G′ and G″, exhibited a power‐law behavior, that is, G′(ω) ∼ ω0.2–0.4 and G″(ω) ∼ ω0.46−0.50 within the frequency range where G′ dominates G″. In addition, the elasticity of the gels, which results from the attractive particle bonds, increased markedly with increasing polymer concentration. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45259.

Effect of Polymer Molecular Weight on the Crystallization Behavior of Indomethacin Amorphous Solid Dispersions

The influence of the molecular weight of polyvinylpyrrolidone (PVP) on the molecular mobility and physical stability of indomethacin (IMC)–PVP solid dispersions was investigated over a wide temperature range in the supercooled state. As the polymer molecular weight increased, there was a decrease in molecular mobility as evident from the longer α-relaxation times. Inhibition of IMC crystallization also increased as a function of polymer molecular weight. The extent of H-bonding interaction between drug and polymer, quantified by ssNMR, was independent of polymer molecular weight. Over a polymer concentration range of 5–20% w/w, the temperature dependence of mobility and viscosity was reasonably similar for different grades of PVP. It was concluded that the increase in effectiveness in crystallization inhibition as a function of polymer molecular weight is due to the increased viscosity, which slows down the mobility of these systems.

Colloidal properties and in vitro evaluation of Hydroxy ethyl cellulose coated iron oxide particles for targeted drug delivery

In this study, superparamagnetic iron oxide (Fe3O4) nanoparticles were prepared for the targeted drug delivery applications by controlling the colloidal properties with a cellulosic polymer that is Hydroxy ethyl cellulose (HEC). Fe3O4 particles were treated with HEC in a variable range of polymer concentration. Rheological, electrokinetic, magnetorheological and morphological properties of the dispersions were investigated to have stable and fully covered surfaces of Fe3O4 particles by coating with HEC and obtaining non-toxic biocompatible multifunctional magnetic particles. Fully coated HEC and iron-oxide particles were characterized thermally, magnetically and tested for toxicity in vitro. Then Doxorubicin hydrochloride (DOX), which is an anticancer drug widely used for cancer therapies, was loaded onto nanoparticles and their drug loading efficiency was determined. Finally, effects of DOX-loaded particles on the cancer cells were examined to report a nano drug system which can potentially open up new possibilities in the design of therapeutic agents. Results indicated that the synthesized nanoparticles in this study could be suitable to magnetically manipulated targeted delivery systems, imaging, magnetic hyperthermia treatments.

Centrifugally spun PHBV micro and nanofibres

This paper reports the first study on centrifugal spinning of PHBV fibres. Fibres were spun from solution using a range of polymer concentrations, spin speeds and spinneret to collector distances. A PHBV polymer concentration of 25% w/v spun at 9000rmin−1 produced the highest quality fibres, with fibre diameters predominantly in the 0.5–3μm range. The rate at which fibre could be produced at the 9000rmin−1 spin speed and with a spinneret to collector distance of 39.2cm was equivalent to 11km of fibre per minute per needle. Average fibre strengths of 3MPa were achieved, together with average moduli of 100MPa, indicating that the fibres had higher strength but lower stiffness than electrospun PHBV. The productivity and mechanical properties achieved, together with the excellent biocompatibility of PHBV, means that these fibres have potential for application in a range of biomedical applications.

Electrospinnability of Poly Lactic-co-glycolic Acid (PLGA): the Role of Solvent Type and Solvent Composition.

In this study, the electrospinnability of poly(lactic-co-glycolic acid) (PLGA) solutions was investigated, with a focus on understanding the influence of molecular weight of PLGA, solvent type and solvent composition on the physical properties of electrospun nanofibers. Various solvents were tested to dissolve two PLGA grades (50 KDa-RG755, 100 KDa-RG750). The viscoelasticity, surface tension, and evaporation rate of the PLGA solutions were characterized prior to the electrospinning process. The resulting electrospun nanofibers were characterized with respect to the morphology and mechanical properties. Two pairs of solvent mixtures, i.e. dimethylformamide (DMF)-tetrahydrofuran (THF) and DMF-chloroform (CHL), were identified to provide a stable cone-jet. Within the polymer concentration range studied (10-30%, w/v), RG750 solutions could be electrospun into uniform fibers at 30% (w/v) or at 20% (w/v) when modifying the solvent composition. In comparison to DMF-THF solution, fibers had larger diameter, higher stiffness and tensile strength when electrospun from DMF-CHL solution. The high molecular weight polymer could ensure sufficient intermolecular interaction to generate uniform fibers. The solvent could influence the morphology and mechanical properties of the electrospun fibers by altering the properties of PLGA solution, and drying rate of fibers in the electrospinning process.

Modeling water partition in composite gels of BSA with gelatin following thermal treatment

A thorough experimental procedure of controlled cooling, isothermal at low temperature, heating, isothermal at high temperature and a second cooling run were carried out to record and rationalise the structural properties of BSA-gelatin mixtures over a wide range of temperature and polymer concentration. Research methodology included small-deformation dynamic oscillation in-shear, micro-differential scanning calorimetry, scanning electron microscopy and semi-theoretical modeling based on ideas of relating the elastic modulus of amorphous synthetic polymers to the topology of their binary blends. Cooling of solutions from ambient temperature produces gelatin continuous matrices supporting the BSA droplets, and modeling of the mechanical readings using an appropriate Lewis-Nielsen equation argues that the former is a highly hydrophilic molecule. Heating melts the gelatin network and leads to the formation of a continuous BSA structure, with dispersed inclusions of liquid gelatin, but produces a solvent partition factor in favour of the globular-protein gel. Subsequent cooling forms solid-like particles of gelatin within the interstices of the continuous BSA network. Modeling of steric exclusion phenomena in this filler composite using the isostrain blending law further supports the concept of increasing proportions of water being trapped within the continuous matrix of a biphasic gel.

Reduced Crystallization Temperature Methodology for Polymer Selection in Amorphous Solid Dispersions: Stability Perspective.

API-polymer interactions, used to select the right polymeric matrix with an aim to stabilize an amorphous dispersion, are routinely studied using spectroscopic and/or calorimetric techniques (i.e., melting point depression). An alternate selection tool has been explored to rank order polymers for formation of stable amorphous dispersions as a pragmatic method for polymer selection. Reduced crystallization temperature of API, a parameter introduced by Zhou et al.,1 was utilized in this study for rank ordering interactions in API-polymeric systems. The trends in reduced crystallization temperature monitored over polymer concentration range of up to 20% polymer loading were utilized to calculate "crystallization parameter" or CP for two model systems (nifedipine and BI ABC). The rank order of CP, i.e., a measure of API-polymer interaction, for nifedipine followed the order PVP > PVP-VA > Soluplus > HPMCAS > PV Ac > PAA. This rank ordering was correlated to published results of molecular interactions and physical stability for nifedipine. A different rank ordering was observed for BI ABC: PAA > PVP > HPMCAS > Soluplus > PVPV-VA > PVAc. Interactions for BI ABC were not as differentiated when compared to nifedipine based on CP trends. BI ABC dispersions at drug loadings between 40 and 60% were physically stable for prolonged periods under ICH conditions as well as accelerated stress. We propose that large CP differences among polymers could be predictive of stability outcomes. Acceptable stability at pharmaceutically relevant drug loadings would suggest that the relative influence of downstream processes, such as polymer solubility in various solvents, process suitability and selection, and more importantly supersaturation potential, should be higher compared to stability considerations while developing compounds like BI ABC.

Pilot plant experiments and modeling of CaCO3 growth inhibition by the use of antiscalant polymers in recirculating cooling circuits

Recirculating cooling circuits are prone to the deposition of scale on heat exchangers and packing surfaces. The addition of antiscalant polymers is efficient for inhibiting the precipitation of calcium carbonate (CaCO3) because polymers block the active growth sites. In this study, growth inhibition of calcite by using such polymers in industrial pilot plants operating with natural river water, which is critical to mimic a full-scale cooling circuit and accurately evaluate scale inhibition, was reported. Efficiencies of three commercial polymers were compared. The polymers thus investigated demonstrated comparable efficiencies and similar responses to changes in operating conditions.An adsorption-based model was proposed to quantify the inhibition of precipitation kinetics with respect to the process operating conditions and water qualities. Then, the model was validated at a wide range of polymer concentrations, temperatures, and water qualities, representative of industrial systems. A small amount of polymer was sufficient to affect bulk-scale prevention, albeit the efficiency became constant at high polymer concentrations. Under these conditions, a complementary treatment such as acid injection is necessary.

Biodegradable Glycopolymeric Micelles Obtained by RAFT-controlled Radical Ring-Opening Polymerization

The design and synthesis of an entirely degradable glycopolymer micelle was presented. This design relies on the utilization of RAFT-controlled radical ring-opening polymerization (rROP) technique to afford multiple insertions of cleavable ester linkages onto the backbone of the corona. RAFT polymerization using a macroRAFT agent based on poly(ε-caprolactone) PCL was employed to control the polymerization of well-defined statistical glycopolymers of 1-O-acryloyl-2,3:4,5-di-O-isopropylidene-β-d-fructopyranose (1-O-AiPrFru) and 5,6-benzo-2-methylene-1,3-dioxepane (BMDO) monomer. Three block copolymers were synthesized to generate poly(ε-caprolactone)-b-poly[(1-O-acryloyl-2,3:4,5-di-O-isopropylidene-β-d-fructopyranose)-co-(5,6-benzo-2-methylene-1,3-dioxepane)] (PCL-b-P[(1-O-AiPrFru)-co-(BMDO)]) with varying block lengths. Self-assembly of the deprotected block copolymers generated nonspherical egg shaped micelles, where the shorter chains PCL106-b-P[(1-O-AFru)69-co-(BMDO)9] underwent self-assembly forming micelles with the hydrodynamic diameter (DH) of 106 nm. The biodegradation of these micelles were investigated via enzymatic degradation by Lipase Pseudomonas sp., indicating entirely degradable architectures, which are no longer visible via dynamic light scattering (DLS). SEC further confirmed the appearance of fragmented glycopolymeric units. In vitro cell proliferation assay of the micelles and their degradation products revealed no toxicity against healthy human fibroblast HS27 and breast cancer MDA-MB-231 cell lines. The polymer concentration range tested was up to 0.20 mg·mL–1 with the cell viabilities of ≥95%.

Molecular mobility in glassy dispersions.

Dielectric spectroscopy was used to characterize the structural relaxation in pharmaceutical dispersions containing nifedipine (NIF) and either poly(vinyl) pyrrolidone (PVP) or hydroxypropyl methylcellulose acetate succinate (HPMCAS). The shape of the dielectric response (permittivity versus log time) curve was observed to be independent of temperature. Thus, for the pure NIF as well as the dispersions, the validity of the time-temperature superposition principle was established. Furthermore, though the shape of the full dielectric response varied with polymer concentration, the regime related to the α- or structural relaxation was found to superimpose for the dispersions, though not with the response of the NIF itself. Hence, there is a limited time-temperature-concentration superposition for these systems as well. Therefore, in this polymer concentration range, calculation of long relaxation times in these glass-forming systems becomes possible. We found that strong drug-polymer hydrogen bonding interactions improved the physical stability (i.e., delayed crystallization) by reducing the molecular mobility. The strength of hydrogen bonding, structural relaxation time, and crystallization followed the order: NIF-PV P>NIF-HPMCAS>NIF. With an increase in polymer concentration, the relaxation times were longer indicating a decrease in molecular mobility. The temperature dependence of relaxation time, in other words fragility, was independent of polymer concentration. This is the first application of the superposition principle to characterize structural relaxation in glassy pharmaceutical dispersions.

Energetics of phase separation in aqueous solutions of poly(vinyl methyl ether)

Phase separation in aqueous solutions of poly(vinyl methyl ether) was first investigated by high-sensitivity differential scanning calorimetry at normal and high pressures. Thermograms of the phase separation had two singular points: a binodal point (Tt,1) and a point of the three phases coexistence (Tt,2). At normal pressure the temperature Tt,1 decreased slightly and the temperature Tt,2 was constant (36.8 ± 0.1°С) upon increasing the polymer concentration from 0.01 to 0.25%. The transition enthalpy and heat capacity increment did not depend on the polymer concentration (Δth = 88.0 ± 1.2 J g−1; Δtcp = −1.0 ± 0.1 J g−1 K−1). The calorimetric experiments at high pressures were carried out up to pressure 170 MPa in the range of polymer concentrations 0.1–1.1%. When pressure increased the temperature Tt,1 dropped by 10 °C, the temperature Tt,2 increased by 15 °C, the total transition enthalpy reduced 1.5 fold and the transition heat capacity increment remained virtually unchanged. These data reveal that the sequential phase transitions, which the diluted aqueous solutions of poly(vinyl methyl ether) undergo upon heating, have different nature.

Small-Angle Neutron Scattering Study of Interplay of Attractive and Repulsive Interactions in Nanoparticle-Polymer System.

The phase behavior of nanoparticle (silica)-polymer (polyethylene glycol) system without and with an electrolyte (NaCl) has been studied. It is observed that nanoparticle-polymer system behaves very differently in the presence of electrolyte. In the absence of electrolyte, the nanoparticle-polymer system remains in one-phase even at very high polymer concentrations. On the other hand, a re-entrant phase behavior is found in the presence of electrolyte, where one-phase (individual) system undergoes two-phase (nanoparticle aggregation) and then back to one-phase with increasing polymer concentration. The regime of two-phase system has been tuned by varying the electrolyte concentration. The polymer concentration range over which the two-phase system exists is significantly enhanced with the increase in the electrolyte concentration. These systems have been characterized by small-angle neutron scattering (SANS) experiments of contrast-marching the polymer to the solvent. The data are modeled using a two-Yukawa potential accounting for both attractive and repulsive parts of the interaction between nanoparticles. The phase behavior of nanoparticle-polymer system is explained by interplay of attractive (polymer-induced attractive depletion between nanoparticles) and repulsive (nanoparticle-nanoparticle electrostatic repulsion and polymer-polymer repulsion) interactions present in the system. In the absence of electrolyte, the strong electrostatic repulsion between nanoparticles dominates over the polymer-induced depletion attraction and the nanoparticle system remains in one-phase. With addition of electrolyte, depletion attraction overcomes electrostatic repulsion at some polymer concentration, resulting into nanoparticle aggregation and two-phase system. Further addition of polymer increases the polymer-polymer repulsion which eventually reduces the strength of depletion and hence re-entrant phase behavior. The effects of varying electrolyte concentration on the phase behavior of nanoparticle-polymer system are understood in terms of modifications in nanoparticle-nanoparticle and polymer-polymer interactions. The nanoparticle aggregates in two-phase systems are found to have surface fractal morphology.

Optimization of Polymer-Amended Fly Ash and Paper Pulp Millings Mixture for Alternative Landfill Liner

In 2012 the City of Flagstaff partnered with researchers at the Dept. of Civil and Environmental Engineering at Northern Arizona University to successfully develop a mix design utilizing sludge derived from the manufacturing of recycled paper pulp sludge (PPS) and fly ash as a component of a landfill cap. This research has been extended to explore the addition of polymers to the mix of waste materials in order to optimize a design that would be suitable as a component for an EPA Subtitle D-approvable landfill liner. Cinder Lake Landfill (CLL) serves several communities in Northern Arizona and is managed by the City of Flagstaff. CLL does not have a reliable source of clay needed to construct a required landfill liner, which is necessary for the upcoming 108-acre landfill expansion. However, CLL receives approximately 80 tons of recycled PPS daily from the local tissue manufacturing plant. PPS is currently used as daily cover and was tested for use as part of a landfill cap, as noted above. Incorporating polymers in alternative materials such as PPS and fly ash has the potential to meet performance criteria and be approved by state and federal regulators, and has the potential to save the City millions of dollars over conventional composite liners of geomembrane and clay. Different mixtures of PPS, fly ash and three different polymers are currently being subjected to testing for the following: Water Content, Specific Gravity, Porosity, Organic Content, Atterberg Limits (plasticity), Proctor Compaction, Consolidation, California Bearing Ratio, Shear Strength, Gas Permeability, and Liquid Permeability. The optimal mixture of PPS and fly ash will be blended with a range of polymer concentrations. The goal is to find an optimal mix of PPS, fly ash, and polymer to achieve regulatory standards related to permeability, along with other desirable properties such as strength and flexibility. The optimum mixture(s) will then be subjected to field trials, scheduled to begin in 2016, in which test cells will be created at CLL. The liner will be constructed with the optimized mixture(s), and the cells will be operated as landfills for 1-2 years. Results from lab and field testing will be submitted to federal and state regulators for consideration as an alternative liner approach.

Exploring the dynamics of phase separation in colloid-polymer mixtures with long range attraction.

We have studied the kinetics of phase separation and gel formation in a low-dispersity colloid - non-adsorbing polymer system with long range attraction using small-angle light scattering. This system exhibits two-phase and three-phase coexistence of gas, liquid and crystal phases when the strength of attraction is between 2 and 4kBT and gel phases when the strength of attraction is increased. For those samples that undergo macroscopic phase separation, whether to gas-crystal, gas-liquid or gas-liquid-crystal coexistence, we observe dynamic scaling of the structure factor and growth of a characteristic length scale that behaves as expected for phase separation in fluids. In samples that gel, the power law associated with the growth of the dominant length scale is not equal to 1/3, but appears to depend mainly on the strength of attraction, decreasing from 1/3 for samples near the coexistence region to 1/27 at 8kBT, over a wide range of colloid and polymer concentrations.

Theoretical predictions of structures in dispersions containing charged colloidal particles and non-adsorbing polymers.

We develop a theoretical model to describe structural effects on a specific system of charged colloidal polystyrene particles, upon the addition of non-adsorbing PEG polymers. This system has previously been investigated experimentally, by scattering methods, so we are able to quantitatively compare predicted structure factors with corresponding experimental data. Our aim is to construct a model that is coarse-grained enough to be computationally manageable, yet detailed enough to capture the important physics. To this end, we utilize classical polymer density functional theory, wherein all possible polymer configurations are accounted for, subject to a mean-field Boltzmann weight. We make efforts to counteract drawbacks with this mean-field approach, resulting in structural predictions that agree very well with computationally more demanding simulations. Electrostatic interactions are handled at the fully non-linear Poisson-Boltzmann level, and we demonstrate that a linearization leads to less accurate predictions. The particle charge is an experimentally unknown parameter. We define the surface charge such that the experimental and theoretical gel point at equal polymer concentration coincide. Assuming a fixed surface charge for a certain salt concentration, we find very good agreements between measured and predicted structure factors across a wide range of polymer concentrations. We also present predictions for other structural quantities, such as radial distribution functions, and cluster size distributions. Finally, we demonstrate that our model predicts the occurrence of equilibrium clusters at high polymer concentrations, but low particle volume fractions and salt levels.

Enzymatic PEGylated Poly(lactone-co-β-amino ester) Nanoparticles as Biodegradable, Biocompatible and Stable Vectors for Gene Delivery.

We have developed new, efficient gene delivery systems based on PEGylated poly(lactone-co-β-amino ester) block copolymers that are biodegradable, stable and low in toxicity. The PEG-poly[PDL-co-3-(4-(methylene)piperidin-1-yl)propanoate] (PEG-PPM) diblock and PPM-PEG-PPM triblock copolymers with various compositions were synthesized in one step via lipase-catalyzed copolymerization of ω-pentadecalactone (PDL) and ethyl 3-(4-(hydroxymethyl)piperidin-1-yl)propanoate (EHMPP) with an appropriate PEG (MeO-PEG-OH or HO-PEG-OH). The amphiphilic block copolymers are capable of condensing DNA in aqueous medium via a self-assembly process to form polyplex micelle nanoparticles with desirable particle sizes (70-140 nm). These micelles possess low CMC values and are stable in the medium containing serum protein molecules (FBS). Among the PEG-PPM and PPM-PEG-PPM micelles, the PEG-PPM-15% PDL micelle particles exhibited high DNA-binding ability, the fastest cellular uptake rate and highest gene transfection efficacy. Flow cytometry analysis shows that LucDNA/PEG-PPM-15% PDL polyplex micelles can effectively escape from endosomal degradation after cellular uptake likely due to the presence of the tertiary amine groups in the copolymer chains that act as proton sponges. In vitro cytotoxicity and hemolysis assay experiments indicate that all copolymer samples are nonhemolytic and have minimal toxicity toward COS-7 cells within the polymer concentration range (≤200 μg/mL) used for the gene transfection. These results demonstrate that the PEGylated poly(lactone-co-β-amino ester) block copolymers are promising new vectors for gene delivery applications.