Abstract:
Fibers that are formed from a thermoplastic composition that contains a rigid renewable polyester and has a voided structure and low density are provided. To achieve such a structure, the renewable polyester is blended with a polymeric toughening additive in which the toughening additive can be dispersed as discrete physical domains within a continuous matrix of the renewable polyester. Fibers are thereafter formed and then stretched or drawn at a temperature below the glass transition temperature of the polyester (i.e., "cold drawn").
Abstract:
A film that is formed from a thermoplastic composition is provided. The thermoplastic composition contains a rigid renewable polyester and a polymeric toughening additive. The toughening additive can be dispersed as discrete physical domains within a continuous matrix of the renewable polyester. An increase in deformation force and elongational strain causes debonding to occur in the renewable polyester matrix at those areas located adjacent to the discrete domains. This can result in the formation of a plurality of voids adjacent to the discrete domains that can help to dissipate energy under load and increase tensile elongation. To even further increase the ability of the film to dissipate energy in this manner, the present inventors have discovered that an interphase modifier may be employed that reduces the degree of friction between the toughening additive and renewable polyester and thus reduces the stiffness (tensile modulus) of the film.
Abstract:
A melt-processed protein composition formed from a protein, plasticizer, and an electrophilic reagent is provided. The electrophilic reagent, for instance, may be selected to undergo a nucleophilic addition reaction with free sulfhydryl and/or thiyl radicals to help minimize the formation of disulfide crosslinking bonds that could otherwise lead to protein aggregation during melt processing. To enhance the degree to which the electrophilic reagent can limit crosslinking, a plasticizer is also employed that helps to mediate the adsorption of the electrophilic reagent into the internal structure of the protein, where it can be more stably retained. Furthermore, the temperature and shear rate employed during melt blending may also be selected to be relatively low to help limit polypeptide dissociation, thereby minimizing the impact of aggregation and embrittlement.
Abstract:
A method for forming a composition that includes mixing an antimicrobially active botanical oil (e.g., thymol, carvacrol, etc.) and a modified starch polymer within a melt blending device (e.g., extruder) is provided. Unlike the problems associated with proteins, the use of starch polymers allows for a greater degree of flexibility in the processing conditions and is still able to achieve good properties in the resulting composition. The present inventors have also discovered that a plasticizer may be employed to facilitate melt processing of the starch, as well as to enhance the ability of the botanical oil to flow into the internal structure of the starch where it can be retained in a stable manner. The composition is also typically generally free of solvents. In this manner, the starch will not generally disperse before use and prematurely release the botanical oil. Due to the water sensitivity of the modified starch, however, it may be subsequently dispersed by moisture when it is desired to release the botanical oil.
Abstract:
A method for forming an antimicrobial composition that includes mixing an antimicrobially active botanical oil (e.g., thymol, carvacrol, etc.) and protein within a melt blending device (e.g., extruder) is provided. Despite the problems normally associated with melt processing proteins, the present inventors have discovered that the processing conditions and components may be selectively controlled to allow for the formation of a stable, melt-processed composition that is able to exhibit good mechanical properties. For example, the extrusion temperature(s) and shear rate employed during melt blending are relatively low to help limit polypeptide dissociation, thereby minimizing the impact of aggregation and embrittlement. While the use of such low temperature/shear conditions often tend to reduce mixing efficiency, the present inventors have discovered that a carrier fluid may be employed to enhance the ability of the botanical oil to flow into the internal structure of the protein where it can be retained in a stable manner. The composition is also typically anhydrous and generally free of solvents. In this manner, the protein will not generally disperse before use and prematurely release the botanical oil.
Abstract:
A shaped polymeric material having a three-dimensional configuration with one or more angular displacements is provided. The polymeric material is formed from a thermoplastic composition containing a continuous phase that includes a matrix polymer. A microinclusion additive and nanoinclusion additive are dispersed within the continuous phase in the form of discrete domains, and a porous network is defined in the material.
Abstract:
A polyolefin fiber that is formed by a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and nanoinclusion additive is provided. The nanoinclusion additive is dispersed within the continuous phase as discrete nano-scale phase domains. When drawn, the nano-scale phase domains are able to interact with the matrix in a unique manner to create a network of nanopores.
Abstract:
A polymeric material for use in thermal insulation is provided. The polymeric material is formed from a thermoplastic composition containing a continuous phase that includes a matrix polymer and within which a microinclusion additive and nanoinclusion additive are dispersed in the form of discrete domains. A porous network is defined in the material that includes a plurality of nanopores having an average cross-sectional dimension of about 800 nanometers or less. The polymeric material exhibits a thermal conductivity of about 0.20 watts per meter-kelvin or less.
Abstract:
A technique for initiating the formation of pores in a polymeric material that contains a thermoplastic composition is provided. The thermoplastic composition contains microinclusion and nanoinclusion additives dispersed within a continuous phase that includes a matrix polymer. To initiate pore formation, the polymeric material is mechanically drawn (e.g., bending, stretching, twisting, etc.) to impart energy to the interface of the continuous phase and inclusion additives, which enables the inclusion additives to separate from the interface to create the porous network. The material is also drawn in a solid state in the sense that it is kept at a temperature below the melting temperature of the matrix polymer.
Abstract:
A polyolefin material that is formed by solid state drawing of a thermoplastic composition containing a continuous phase that includes a polyolefin matrix polymer and nanoinclusion additive is provided. The nanoinclusion additive is dispersed within the continuous phase as discrete nano-scale phase domains. When drawn, the nano-scale phase domains are able to interact with the matrix in a unique manner to create a network of nanopores.