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Piezoelectric Polymers

U.S. Patent 8,648,151 (February 11, 2014), “Piezoelectric Polymer Material, Process for Producing Same, and Piezoelectric Element,” Mitsunobu Yoshida, Masanobu Ajioka, Kenichi Goto, Ichiro Fujio, Takaharu Isaki, Takayuki Onogi, Yoshiro Tajitsu, Shinichi Usugi, Takeshi Karino, and Yoshiaki Aso (Mitsui Chemicals, Inc., Minato-Ku, Tokyo, Japan, and Kansai University, Suita-Shi, Osaka, Japan).

Piezoelectric materials become charged when stressed and stressed when charged. These materials are very useful in electronic devices, but common piezoelectric materials are ceramics containing lead, with environmental and mechanical problems. Piezoelectric polymers have reduced environmental problems and are more flexible; however, these polymers are inferior to ceramics in several ways.

Yoshida et al. developed an improved piezoelectric polymer based on helical chiral polymers with optical activity and weight-average molecular weights from 50,000 to 1,000,000. They have an x-ray crystallinity of 40 to 80% and do not requiring poling. Examples include polypeptides, cellulose derivatives, polylactic acid resins, polypropylene oxides, and poly(beta-hydroxy butyric acid). Polylactic acid polymers are preferred. The piezoelectric polymer is crystalline, with a high degree of crystallinity and orientation.

Toughened Films

U.S. Patent 8,652,623 (February 18, 2014), “Coextruded Films with Low Temperature Impact Resistance,” Heinz Pudleiner, Robert Maleika, Birgit Meyer Zu Berstenhorst, Frank Buckel, and Klaus Meyer (Bayer MaterialScience AG., Leverkusen, Germany).

Low-temperature brittleness continues to be a problem for most polymeric materials. For example, known acrylate/polycarbonate films have an inadequate low-temperature impact resistance, a property especially important for glazing. 

Pudleiner et al. developed multilayer acrylic/polycarbonate films which are impact resistant by the falling ball test at -30°C. The acrylic layer thickness is critically important and should be less than 20 microns. The acrylic layers are laminated to polycarbonates and can be formed by coextrusion.

Self-Cleaning Films

U.S. Patent 8,652,646 (February 18, 2014), “Film having a Photocatalytic Active Surface,” Dirk Heukelbach and Klaus Thinnes (Renolit AG., Worms,
Germany).

Films have been used extensively outdoors as tarps, awnings, swimming pool films, or blinds and coatings for windows, doors, shutters, folding shutters, and other facade elements. These films must provide protection against impacts and water and moisture and, above all, they must be weatherproof. 

Recently, attempts have been made to make surfaces self-cleaning via the lotus effect, based on very fine surface roughness. Heukelbach and Thinnes developed a weatherproof film consisting of a substrate, a barrier layer, and a surface layer based on polymethacrylate. A self-cleaning effect is induced with 0.1-15 wt% of a photocatalyst in the exposed surface. The photocatalyst should be exposed at the surface to the environment for maximum effect. The result is that the surface contamination is decomposed or lightened, reducing the need for cleaning.

Thermoset Recycling

U.S. Patent 8,653,150 (February 18, 2014), “Method for Decomposing Thermoset Resin and Recovering Decomposition Product,” Takumi Izumitani, Takaharu Nakagawa, Masaru Hidaka, Keishi Shibata, and Junko Matsui (Panasonic Corporation, Osaka, Japan, and International Center for Environmental Technology Transfer, Mie, Japan).

As the amount of solid waste mass grows, more and more pressure is on the plastics community to recycle and reuse plastics. Recycling thermoplastics requires separation and remelting and reprocessing. Thermosets do not remelt easily and are more difficult to recycle; however, if properly decomposed, they can be a resource for new raw materials. 

Izumitani et al. found that polyester thermosets can be decomoposed in subcritical water, generating useful raw materials for new polyesters. “Subcritical water” is water above 140°C and less than 374°C at a pressure of 0.36 MPa (i.e., saturated water vapor pressure at 140°C) or more. The result is useful acid residue and a useful crosslinking residue.

Polyethylene Melts

U.S. Patent 8,653,196 (February 18, 2014), “Method for Preparing Polyethylene with High Melt Strength,” Nicolas C. Mazzola, Mariana D. Mancini, and Jorge C. Gomes (Dow Global Technologies, LLC, Midland, Michigan, USA).

Melt strength is a practical measurement based on elongational deformation. Good melt strength is important for stability during coating, blowing film, fiber spinning, and foaming. This melt strength is related to molecular entanglements and relaxation times, which is a function of molecular weight and branching. Melt strength can be increased by peroxide crosslinking, but it is unpredictable and can affect other properties.

Mazzola, Mancini, and Gomes increased polyethylene melt strength by reaction with an alkoxy amine during extrusion, such as (R₁)(R₂)-N-O-R₃ where R₁, R₂, and R₃ are hydrogen or hydrocarbon groups. Their effective loading ranges from 0.01 to 5 wt% in the polyethylene. Adding the amine results in 30-50% increased melt strength, leading to materials suited for films, sheets, pipes, and blow-molded articles.

Polyrotaxanes

U.S. Patent 8,658,725 (February 25, 2014), “Material having Cross-Linked Polyrotaxane, and Method for Producing Same,” Katsunari Inoue, Yuki Hayashi, and Junko Inamura (Advanced Softmaterials Inc., Kashiwa-shi, Japan).

High dielectric-constant materials are needed for electronic applications such as actuators. A high dielectric constant requires great molecular flexibility. A high dielectric elastomer with flexibility and a high dielectric constant is needed, but there is no material which fully meets the requirements.

Inoue, Hayashi, and Inamura developed such an elastomer with high flexibility and a high dielectric constant based on mixtures of polyrotaxanes. Polyrotaxane polymers are blends in which linear polymer chains pass through cyclic polymer structures and cannot be disconnected because of blocking groups. The chains slip easily through each other without separation, leading to extreme flexibility. The resulting material is solvent-free with a dielectric constant at 1 kHz of at least 6.0.

Magnetic Polymers

U.S. Patent 8,658,751 (February 25, 2014), “Molecule-Based Magnetic Polymers and Methods,” Chang Dae Han and Wenyi Huang (University of Akron, Akron, Ohio, USA).

Magnets are indispensable in many mechanical and electronic devices. Traditional magnets are transition, lanthanide, or actinide metals. The magnetism arises from the magnetic dipole moment of unpaired electrons in the d- or f-orbitals. Previous research attempts to design and synthesize organic molecular magnets and high-spin molecules have been unsuccessful. 

Han and Huang developed magnetic polymers with high Curie temperatures. These are polymers of an organometallic monomer with unpaired electrons. The monomers form donor-acceptor polymers with an electron acceptor, including transition metals, iron, cobalt, or nickel within a ferrocene, cobaltocene, or nickelocene monomer. The monomers can then be polymerized to covalently linked, molecule-based magnetic groups. The synthesized polymers are soluble in organic solvents, since they may have long, flexible, bulky side chains.

Doped Polyaniline

U.S. Patent 8,658,759 (February 25, 2014), “Switchable Self-Doped Polyaniline,” Bhavana A. Deore, Insun Yu, and Michael S. Freund (Univ. of Manitoba, Winnipeg, Canada).

Polyaniline, one of the most promising intrinsically conducting polymers, has received considerable attention due to its straightforward polymerization, chemical stability, high conductivity, and potential for use in electronic devices, batteries, and sensors. A major breakthrough was the discovery of self-doped polyaniline; however, the material shows reduced mechanical stability and decreased conductivity due to steric effects.

Deore, Yu, and Freund developed a substituted polyaniline whose self-doped state can be controlled via complexes between boronic acid groups along the backbone with D-fructose in the presence of fluoride. This enables the formation of a water-soluble, self-doped conducting polymer during polymerization, which facilitates the growth of polyaniline over a wide pH range.

Superbandages

U.S. Patent 8,658,851 (February 25, 2014), “Devices with Cells Cultured on Flexible Supports,” John Dahlquist and Susan Schaeffer (Keracure, Inc., Chicago, Illionis, USA).

Metabolically active cultured cells are useful in a variety of applications from tissue repair to tissue regeneration. Although there are many methods promoting wound healing, some wounds still do not heal satisfactorily.

Wound healing can be expedited using active keratinocytes or fibroblasts on flexible supports. Dahlquist and Schaeffer developed wound healing bandages by culturing cells with the desired metabolic activity on flexible supports. Keratinocytes are grown directly on a high-density polyethylene/ethylene vinyl acetate laminate. Keratinocytes grown on this flexible support showed increased metabolic activity compared to those grown on other solid supports, such as porous beads, and promote healing.

Neutron Shielding

U.S. Patent 8,664,629 (March 4, 2014), “Boron Cage Compound Materials and Composites for Shielding and Absorbing Neutrons,” Daniel E. Bowen, III, and Eric A. Eastwood (Honeywell Federal Manufacturing & Technologies, LLC, Kansas City, Missouri, USA).

Ionizing radiation is widely used in industry and medicine. Radiation not only poses health problems for living organisms, such as mutations, it also degrades satellites, aircraft, and nuclear reactors. Neutrons are especially dangerous. Thus there is a continuing need for improved materials for shielding and protecting people, materials, and objects from radiation.

Bowen and Eastwood developed boron cage compounds (BCCs; boranes and carboranes) as fillers for shielding and absorbing neutrons. BCC composites consist of a host polymer and BCC units attached to the polymer chains. These composites can be used to form different articles for shielding and absorbing neutrons. The filled materials can form fabrics, coatings, foams, and solid shielding structures. The active filler loading ranges from 1 to 25 wt%.

Cardboard Bicycles

U.S. Patent 8,662,513 (March 4, 2014), “Recyclable Cardboard Bicycle,” Izhar Gafni (I.G. Cardboard Technologies Ltd., Ahituv, Illinois, USA).

Typically, bicycles, tricycles, and scooters are made of durable, lightweight materials that are not easily recycled. These vehicles are purchased and kept until they become unusable due to damage or age. At this point the vehicle is usually discarded into a landfill. 

Gafni developed human-powered land vehicles for human riders constructed from shreddable, recyclable materials. The material is based on honeycomb cardboard including polyethylene terephthalate and other components. The structure includes a pulpably recyclable fork, wheels, and a hub with a recyclable drive train. The cardboard can consist of flutes lined with plastic and impregnating agents. The cardboard is also treated with either organic or inorganic sealant for waterproofing, and is made flame resistant.