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Nonbiodegradable (co)polymers with all-carbon backbone produced via radical polymerization are used in various applications. For some applications, like for example in skincare and haircare, these polymers are nonrecoverable and therefore would be preferably made biodegradable. Therefore, inserting ester bonds in the backbone via radical ring opening terpolymerization of acrylates and 2-methylene-1,3 dioxepane (MDO) could be a suitable approach to obtain biodegradable terpolymers. This report investigates the influence of batch versus semibatch process on the polymerization of three terpolymerization systems viz. (i) methacrylamide (MAAM)/n-butyl acrylate (nBA)/BMDO (5,6-Benzo-2-Methylene-1,3-Dioxepane), (ii) MAAM/nBA/MDO, and (iii) methyl methacrylate (MMA)/VAc (vinyl acetate) /MDO. We demonstrate the improvement in number of ester groups inserted and the homogeneity of insertion via semibatch polymerization processes. The process is guided via optimal monomer addition feeding profiles generated using the reactivity ratios of comonomers. Such improved insertion was demonstrated by the molecular weight distribution of fragments after alkali degradation in the investigated systems.

This work describes the important effects of microstructural features on crystalline structure, mechanical behavior and molten state response for poly (propylene-co-1-pentene-co-1-heptene) terpolymers. The study was carried out in a wide range of compositions, varying the 1-pentene/1-heptene ratio and the thermal history applied. Molecular features, as propylene sequences and compositional triads, allow predicting the material behavior. Moreover, rheological response has demonstrated the influence of molecular weight, comonomer content and short-chain branches on the properties. The flow activation energy can justify the importance of the material density over the whole spectrum of properties.

Several Ziegler-Natta copolymers of iPP with ethylene or 1-butene, and terpolymers with both counits have been characterized, devoting special attention to the effect of composition and processing conditions on the crystal structure and final properties. DSC and X-ray diffraction were used to study the polymorphism of copolymers and terpolymers. Comonomer insertion interrupts the isotactic sequences, acting as a structural defect, and the formation of g form is enhanced. Moreover, crystallinity decreases and crystal structure is modified. Comonomer type and concentration determine the extent of these modifications, resulting in important changes in macroscopic properties. In particular, the excellent optical properties of the analyzed terpolymers make them very attractive for applications such as transparent film or packaging

Reliable measurements of the particulate dynamics and morphology within solid rocket motors are required to develop and validate numerical codes, as well as to develop improved understanding. For example, quantifying accurately the effect of binder systems on aluminum and alumina particle morphology in realistic environments is of great interest. An effort is underway to develop experimental methods to unobtrusively characterize the morphology and velocity of particles leaving the burning surface of a solid propellant. Atmospheric tests were considered first to develop and validate the diagnostic methods. Elevated pressure experiments were then conducted inside a windowed pressure vessel. Two composite propellants with different binders were considered, one consisting of HTPB/AP/Al and another with PBAN/AP/Al. The dynamics of aluminum and alumina particles formed during the combustion were accurately tracked, even on and near the propellant surface. A maximum velocity of ~7.21 ft/s (2.2 m/s) in the axial direction was observed during testing of the HTPB/AP/Al propellant, while a maximum velocity of 6.33 ft/s (1.93 m/s) was observed for the AP/PBAN/AL, both at 1 atm. The maximum velocity for the PBAN/AP/Al propellant decreased to 5.38 ft/s (1.64 m/s) during the elevated pressure tests. Distinct differences in the morphology of the particles, caused by the different binder systems used in the propellant mixtures, can be clearly seen in the results. During the experiments, images were gathered at 6000 frames per second by a high-speed camera using a variety of optics and filters. The gathered data was processed using statistical image correlation velocimetry. Results were also obtained in cross flow using a modified windowed motor., For presentation at the JANNAF Interagency Joint Propulsion Meeting (56th) to be held in Las Vegas, NV on 14-17 April 2009. Prepared in cooperation with En'Urga Inc., West Lafayette, IN.

In this program, Penn State, TRS Technologies, and Electronic Concepts, Inc. (ECI) worked together to perform a preliminary investigation of various issues related to the ferroelectric relaxor terpolymer for energy storage capacitors. In this program, terpolymers of P(VDF-TrFE-CFE) with different compositions were synthesized, and some of them were fabricated into thin films at ECI. The authors also characterized the electric energy density and the AC and DC resistivities of the terpolymers; investigated the graceful failure and improvement in the breakdown strength and the graceful failure of the terpolymer films; and designed and fabricated a high-voltage and high-speed discharge circuit. The results are summarized in this report. (11 tables, 13 figures), Prepared in collaboration with TRS Technologies, Inc., State College, PA, and Electronic Concepts, Inc.

This report contains several symposia papers and journal articles on the following topics: Characterization of Electrostrictive P(VDF-TrFE) Copolymers Film for High Frequency and High Load Applications; New Electrostrictive PVDF Copolymers for Large-Strain Actuator Application; Synthesis and Electric Property of VDF/TrFE/HFP Terpolymers; Giant Electrostrictive Response in Poly(Vinylidene-Fluoride-Hexafluoropropylene) Copolymer; Electro-Mechanical Properties of Electron Irradiated P(VDF-TrFE) Copolymers under Different Mechanical Stresses; Electroactive Polymer Actuators and Devices - P(VDF-TrFE)-based Electrostrictive Co/Ter-polymers and its Device Performance; Electrostrictive Poly(Vinylidene Fluoride-Trifluoroethylene) Copolymers; Ferroelectric and Electromechanical Properties of Poly(Vinylidene-Fluoride-Trifl uoroethylene-Chlorotrifluoroethylene) Terpolymer; High Electromechanical Coupling Factor and Electrostrictive Strain over Broad Frequency Range in Electrostrictive Poly(Vinylidene Fluoride-Trifluoroethylene) Copolymer Films; Structural Changes and Transitional Behavior Studied from Both Micro- and Macroscale in the High-Energy Electron-Irradiated Poly(vinylidene Fluoride-Trifluoroethylene) Copolymer; High-performance Micromachined Unimorph Actuators based on Electrostrictive Poly(Vinylidene Fluoride-Trifluoroethylene) Copolymer; Design, Fabrication, and Performance of a Flextensional Transducer Based on Electrostrictive Polyvinylidene Fluoride-Trifluoroethylene Copolymer; High Electromechanical Responses in a Poly(Vinylidene Fluoride-Trifluoroethylene-Chlorofluoroethylene) Terpolymer; Device Fabrication and Performance of Elecrostrictive P(VDF-TrFE) Based Actuators and Transducers; Chemical and Physical Changes Associated with High-Strain Electrostriction In Beta-Irradiated PVDF-TrFE; Molecular Modeling Studies on High-Strain, Electrostrictive Terpolymer; Characterization and Development of P(VDF-TrFE) Based High Performance Electroactive Terpolymers., Sponsored in part by Grant No. ECS-9710459. Appendices 10-32. See also ADA424709.

The objective of this DARPA program is to develop high performance electroactive polymers and demonstrate the new polymers for underwater high-power sonar transducers. Through the support of this DARPA program, the electromechanical responses of the high energy electron irradiated copolymer have been improved significantly and PVDF based electrostrictive terpolymers with electromechanical performance better than the irradiated copolymers have been developed. The scale-up of the terpolymer production is current underway and the fabrication techniques for the multilayer transducer elements have been examined. Multilayer transducer elements have been fabricated by manually gluing the layer together and more recently at Electronic Concepts, Inc. by multilayer spiral roll. The preliminary test results on the transducer elements indicate that the transducers have the potential to be used for high power sonar transducer. The objective of this DARPA program is to develop high performance electroactive polymers and demonstrate the new polymers for underwater high-power sonar transducers. Through the support of this DARPA program, the electromechanical responses of the high energy electron irradiated copolymer have been improved significantly and PVDF based electrostrictive terpolymers with electromechanical performance better than the irradiated copolymers have been developed. The scale-up of the terpolymer production is current underway and the fabrication techniques for the multilayer transducer elements have been examined. Multi layer transducer elements have been fabricated by manually gluing the layer together and more recently at Electronic Concepts, Inc. by multilayer spiral roll. The preliminary test results on the transducer elements indicate that the transducers have the potential to be used for high power sonar transducer., See also ADA424708.

Laboratory studies were conducted to determine the rates at which perchlorate is released from perchlorate-containing solid propellants and the influence of temperature and salinity on the rates. Perchlorate release rates from carboxyl-terminated polybutadiene (CTPB), hydroxyl-terminated polybutadiene (HTPB), polybutadiene-acrylic acid-acrylo-nitrile terpolymer (PBAN), and polyurethane (PU) solid propellants were determined and are reported as diffusion coefficients. The diffusion coefficients for all propellant types and conditions tested were in the range of 3.6 x 10(exp -12) to 1.1 X 10(exp -13) sq m/s. Modeling studies of solid-propellant debris impacts for Delta IV and Atlas V cases were also conducted using an improved methodology based on the ACTA debris model., The original document contains color images. All DTIC reproductions will be in black and white.

A new class of ferroelectric terpolymers having an exceptionally large electrostrictive response ( 3%) induced by external electric field at ambient temperature comprise 50-80 mole % of vinylidene fluoride (VDF), 15-40 mole % of trifluoroethylene (TrFE) and 2-20 mole % of at least one bulky monomer, such as chlorotrifluoroethylene (CTFE) or hexafluoropropene (HFP). These semicrystalline terpolymers behave like a ferroelectric relaxor having a rapid electric field-induced mechanical response se, due to a low Curie temperature (phase transition between polar and nonpolar crystalline domains at or near ambient temperature) and high dielectric constant. A combination of bulk polymerization and free radical polymerization using oxidation adducts of an organoborane as the free radical initiator may be used to prepare the terpolymers, such that the terpolymers are characterized by good processibility, high purity and uniform molecular structure.

Several important progresses have been made in the past three-year ONR program. (i) We have developed a new polymer chemistry that allows the polymerization of fluoro-monomers in bulk condition at ambient temperature. (ii) A new family of ferroelectric polymorphs fluoro-terpolymers have been prepared, which comprise vinylidene difluoride (VDF), trifluoroethylene (TrFE), and a chloro-containing third monomer, including vinyl chloride (VC), 1, 1-chlorofluoroethylene (CFE), chlorodifluoroethylene (CDFE), chlorotrifluoroethylene (CTFE). The new terpolymers show narrow molecular weight and composition distributions and good processibility. (iii) The terpolymers exhibit excellent electric properties. Comparing with the known VDF/TrFE copolymer, the slightly bulky chlorine atoms randomly distributed along the polymer chain spontaneously alter the crystalline phase from Beta-phase (all-trans conformation) to gamma-phase (tttg+ttg- conformation), without significant reduction of overall crystallinity. The Curie (F-P) transition from gamma-phase to alpha-phase (tg+tg- conformation) occurs at near ambient temperature, with a very small activation energy and slim hysteresis loop during heating and cooling cycle. The terpolymers show high dielectric constant (>50) and large electrostrictive response (^5%) at ambient temperature, and exhibiting common ferroelectric relaxor behaviors with a broad dielectric peak that shifted toward higher temperatures as the frequency increased, and a slim polarization hysteresis loop at near the dielectric peak (around ambient temperature).

The number of phases, transition temperatures, and microhardness of a series of poly(ester ether carbonate) (PEEC) multiblock terpolymers with poly(butylene terephthalate) (PBT) hard segments have been investigated as a function of ether/carbonate (EC) soft-segment composition at constant PBT content. The polymerization degree of PBT and the intrinsic viscosity of the terpolymers were determined by viscosimetry. The degree of crystallinity, long spacing, glass transitions Tg, and melting temperature were derived by means of x-ray diffraction, dynamic mechanical thermal analysis (DMTA), and differential scanning calorimetry (DSC) measurements. Surface mechanical properties were studied by microindentation tests. It was found that the terpolymer consists of two amorphous (EC and PBT) phases and one crystalline (PBT) phase. The Tg value of PBT does not depend on the chemical composition of the soft segments, in the contrast to the Tg of the soft-segment amorphous phase. Introduction of polycarbonate moities in the soft segments induces an increase of Tg by 50°C without formation of an additional (third) amorphous phase. The reduced crystallizability of PBT hard segments (by a factor of 3) is explained by this decrease of flexibility of the soft segments, which also causes a twofold reduction in the microhardness values. The dominating contribution of crystallinity to the microhardness is shown. However, the much lower measured overall micro-hardness in contrast to the one calculated by means of the additive law is explained by the plasticizing effect of the soft amorphous phase. This assumption is in agreement with the structure model derived from the small-angle x-ray (SAXS) and wide-angle x-ray (WAXS) data.

Molecular weights above one million were achieved for methylvinylsilphenylene-siloxane terpolymers using a two-stage polymerization technique which was successfully scaled up to 200 grams. The resulting polymer was vulcanized by two different formulations and compared to an identically formulated commercial methylvinyl silicone on the basis of ultimate strength, Young's modulus, percent elongation at failure, and tear strength. Relative thermal/oxidative stabilities of the elastomers were assessed by gradient and isothermal thermogravimetric analyses performed in both air and nitrogen. The experimental elastomer exhibited enhanced thermal/oxidative stability and possessed equivalent or superior mechanical properties. The effect of variations in prepolymer molecular weight on mechanical properties was also investigated.

Procedures for the radiation induced grafting of polyethylene film which yield a variety of modified polyethylene membranes have been established. Modification of the polyethylene was accomplished by grafting with acidic monomers such as acrylic and methacrylic acids, basic monomers such as aminoalkyl methacrylates and vinyl-pyridines, and neutral monomers such as hydroxyalkyl methacrylates. Some graft terpolymers were prepared by incorporating relatively hydrophobic monomers such as acrylonitrile, acrylamide, or vinyl acetate into the grafting solution along with acrylic acid. Crosslinking during grafting was accomplished by use of difunctional monomers in the grafting solution. jg p10