The notched Izod impact toughness and tensile elongation of poly(lactic acid) (PLA)-homopolymers are increased by about 2 to about 4 times by blending therewith a PLA-copolymer having a difunctional flexible middle segment such as a polysiloxane or a polyether from about 0.6 wt. % to about 20 wt. %. The PLA-homopolymer-PLA-copolymer blend having a difunctional flexible polymer from about 0.5 wt. % to about 10 wt. % is thermally annealed to provide impact toughness of at least about 5 kJ/m.sup.2 and tensile elongation of greater than 12%. This exceptional improvement observed in the PLA blend is a synergistic effect of the addition of the difunctional flexible polymer of the copolymer and thermal annealing. The improvement observed in the mechanical properties with high PLA homopolymer content above about 90 to about 98 wt. % is unusual and results in an increased scope of molding and thermoforming applications. The annealed PLA-copolymers having a difunctional flexible middle segment have also been found to have improved notched Izod impact properties.

A branched degradable polyethylene glycol derivative with a high molecular weight that does not cause vacuolation of cells is provided. A branched degradable polyethylene glycol derivative represented by the following formula (1), containing, in a molecule, an oligopeptide that is degraded in the cells:

##STR00001##

wherein k.sub.1 and k.sub.2 are each independently 1-12, j.sub.1 and j.sub.2 are each independently 45-950, R is a hydrogen atom, a substituted or unsubstituted alkyl group having 1-12 carbon atoms, a substituted aryl group, an aralkyl group or a heteroalkyl group, Z is an oligopeptide that is degraded by enzyme in the cells, X is a functional group capable of reacting with a bio-related substance, and L.sub.1 and L.sub.2 are each independently a single bond or a divalent spacer.

Disclosed herein is a shelf-stable, two-part formula for making an antimicrobial biphasic polymer. Some variations provide a two-part formula for fabricating a biphasic polymer, wherein the two-part formula consists essentially of (A) a first liquid volume, wherein the first liquid volume comprises: a structural phase containing a solid structural polymer; a transport phase containing a solid transport polymer; a chain extender; a curing catalyst; a first solvent; and (B) a second liquid volume that is volumetrically isolated from the first liquid volume, wherein the second liquid volume comprises: a crosslinker that is capable of crosslinking the solid structural polymer with the solid transport polymer; and a second solvent. An antimicrobial agent (e.g., quaternary ammoniums salts) may be contained in the first liquid volume or in the second liquid volume. Methods of making and using the antimicrobial biphasic polymer are described.

Disclosed herein is a shelf-stable, two-part formula for making an antimicrobial biphasic polymer. Some variations provide a two-part formula for fabricating a biphasic polymer, wherein the two-part formula consists essentially of (A) a first liquid volume, wherein the first liquid volume comprises: a structural phase containing a solid structural polymer; a transport phase containing a solid transport polymer; a chain extender; a curing catalyst; a first solvent; and (B) a second liquid volume that is volumetrically isolated from the first liquid volume, wherein the second liquid volume comprises: a crosslinker that is capable of crosslinking the solid structural polymer with the solid transport polymer; and a second solvent. An antimicrobial agent (e.g., quaternary ammoniums salts) may be contained in the first liquid volume or in the second liquid volume. Methods of making and using the antimicrobial biphasic polymer are described.

The invention discloses a lignin degradation product-bisphenol A-polyurethane polycondensate additive, and a preparation method thereof. Lignin is used as a raw material, and is degraded by an alkali activator, a metal catalyst and nitrobenzene to obtain the lignin degradation product; then, the obtained lignin degradation product is uniformly mixed with bisphenol A, and polyurethane is added; finally, the additive is obtained after heating reaction and drying. The preparation process of the invention is simple, and the obtained lignin degradation product has a small and stable molecular weight and has abundant phenolic hydroxyl and alcoholic hydroxyl sites, which can improve the dispersibility of the product, with strong cohesiveness and good waterproofness. It solves the problem of industrial application that lignin replaces part of phenols in the prior art, which leads to the decline of product performance, improves the total substitution rate of chemicals derived from biomass to bisphenol A derived from fossil resources, and significantly reducing the discharge of phenolic compounds. The additive is an environment-friendly polymeric material with excellent development potential.

The invention discloses a lignin degradation product-bisphenol A-polyurethane polycondensate additive, and a preparation method thereof. Lignin is used as a raw material, and is degraded by an alkali activator, a metal catalyst and nitrobenzene to obtain the lignin degradation product; then, the obtained lignin degradation product is uniformly mixed with bisphenol A, and polyurethane is added; finally, the additive is obtained after heating reaction and drying. The preparation process of the invention is simple, and the obtained lignin degradation product has a small and stable molecular weight and has abundant phenolic hydroxyl and alcoholic hydroxyl sites, which can improve the dispersibility of the product, with strong cohesiveness and good waterproofness. It solves the problem of industrial application that lignin replaces part of phenols in the prior art, which leads to the decline of product performance, improves the total substitution rate of chemicals derived from biomass to bisphenol A derived from fossil resources, and significantly reducing the discharge of phenolic compounds. The additive is an environment-friendly polymeric material with excellent development potential.

An interpenetrating network (IPN) polymer membrane material includes a soft polyurethane interspersed with a crosslinked conducting polymer. The material can be reversibly “switched” between its oxidized and reduced states by the application of a small voltage, ˜1 to 4 volts, thus modulating its diffusivity.

An interpenetrating network (IPN) polymer membrane material includes a soft polyurethane interspersed with a crosslinked conducting polymer. The material can be reversibly “switched” between its oxidized and reduced states by the application of a small voltage, ˜1 to 4 volts, thus modulating its diffusivity.

Disclosed embodiments relate to a combination axial fan and LED lighting system configured to fit into the footprint of a standard ceiling tile. Disclosed embodiments further include ceiling tiles with a built-in fan and/or LED lighting. The disclosed systems may include one or more UV-C light sources which irradiate contaminants as air flows through the UV-C unit. The UV-C unit is mounted on either a universal mounting mechanism or a mobile support unit to provide mobility to the UV-C unit.

Disclosed embodiments relate to a combination axial fan and LED lighting system configured to fit into the footprint of a standard ceiling tile. Disclosed embodiments further include ceiling tiles with a built-in fan and/or LED lighting. The disclosed systems may include one or more UV-C light sources which irradiate contaminants as air flows through the UV-C unit. The UV-C unit is mounted on either a universal mounting mechanism or a mobile support unit to provide mobility to the UV-C unit.