摘要:
Expanded poly(lactide) (PLA) beads are made by pressurizing PLA beads with carbon dioxide at approximately room temperature, heating the beads under pressure to 90 to 160 C to saturate and partially crystallize the beads, and then depressurizing and cooling the beads. The PLA beads contain a blend of PLLA and PDLA in certain ratios. The beads are useful for making expanded bead foam.
摘要:
2-Acetoxyalkanoic acid esters are made in a reaction of a 3,6-dialkyl-1,4-dioxane-2,5-dione or a poly(α-hydroxyalkanoic acid), an acetate ester and an alcohol or phenol in the presence of a transesterification catalyst. Unlike previous methods for making 2-acetoxyalkanoic acid esters, this process proceeds in high yield and high selectivity to the desired product.
摘要:
2-Acetoxyalkanoic acid esters are made in a reaction of an α-hydroxyalkanoic acid ester and an acetate ester in the presence of a transesterification catalyst. Unlike previous methods for making 2-acetoxyalkanoic acid esters, this process proceeds in high yield and high selectivity to the desired product.
摘要:
Polylactide resin compositions contain certain phosphite esters. The presence of the phosphite ester increases the rate of hydrolysis of the polylactide resin under conditions of moisture (including atmospheric moisture) at mildly elevated temperatures.
摘要:
A polyester blend is made in a reaction of a linear polylactide resin and a thermoplastic epoxy group-containing polymer. The polyester blend is blended with a polyester having a glass transition temperature below 0C to form a polyester blend that is particular useful for making paperboard coatings in a melt extrusion process.
摘要:
Cosmetic compositions contain certain polylactic acid resins as film-formers. The polylactic acid resin is effective at low levels in the composition and is compatible with many organic ingredients commonly used in cosmetic compositions. The cosmetic composition can be formulated as a spray, a lotion, a cream or a paste.
摘要:
Lactic acid equivalents are recovered from a starting lactide stream by catalytically racemizing a portion of the lactide in the stream at a temperature of 180° C. or below. This increases the proportion of two species of lactide (i.e., at least two of S,S-, R,R- or meso-lactide) at the expense of the third species. The racemized mixture so obtained can be separated to recover some or all of one or more of the lactide species from the remaining lactide species, by a process such as melt crystallization or distillation. Impurities in the starting lactide stream usually are retained mostly in the remaining meso-lactide, so a highly purified S,S- and/or R,R-lactide stream can be produced in this manner. Such a purified S,S- and R,R-lactide stream is suitable for polymerization to form a polylactide.
摘要:
Thermal insulation structures include a polymer foam layer adhered to a multi-layer sheet having a non-cellular layer of a heat-resistant thermoplastic and a second non-cellular layer of a polylactide resin. The polylactide resin is a surprisingly good barrier to the diffusion of atmospheric gases into the foam layer and of blowing agents out of the foam layer. Accordingly, the diffusion of atmospheric gases and blowing agents is retarded substantially. This greatly reduces the loss of thermal insulation capacity of the structure due to the replacement of the blowing agent with atmospheric gases. The multi-layer sheet exhibits excellent thermal stability, even when the polylactide in the polylactide layer is highly amorphous.
摘要:
Thermal insulation structures include a polymer foam layer adhered to a non-cellular sheet of a polylactide resin. The polylactide resin is a surprisingly good barrier to the diffusion of atmospheric gases into and blowing agents out of the foam layer. Accordingly, the diffusion of atmospheric gases and the blowing agents is retarded substantially. This greatly reduces the loss of thermal insulation capacity of the structure due to the replacement of the blowing agent with atmospheric gases.
摘要:
Thermal insulation structures include a polymer foam layer adhered to a multi-layer sheet having a non-cellular layer of a heat-resistant thermoplastic and a second non-cellular layer of a polylactide resin. The polylactide resin is a surprisingly good barrier to the diffusion of atmospheric gases into the foam layer and of blowing agents out of the foam layer. Accordingly, the diffusion of atmospheric gases and blowing agents is retarded substantially. This greatly reduces the loss of thermal insulation capacity of the structure due to the replacement of the blowing agent with atmospheric gases. The multi- layer sheet exhibits excellent thermal stability, even when the polylactide in the polylactide layer is highly amorphous.