Poly(butylene succinate-co-terephthalate) (PBST) copolyester, is a new type of biodegradable synthetic polymer material that has emerged in recent years, but it cannot meet the market requirements, because of its low strength. The high-strength and high-modulus polylactic acid (PLA) was blended with PBST to increase its strength, and the chain extender ADR-4370 was used to modify PBST/PLA films by reaction and compatibilization. Compared with the 80/20 wt% PBST/PLA films, the tensile strength after modification with 0.
View Article and Find Full Text PDFPoly (lactic acid) (PLA) blends with different toughening agents were prepared by melt compounding, and the effects of toughening agents on the toughness of PLA, especially the low-temperature toughness, were investigated. All blends were immiscible systems, but the rheological Cole-Cole diagram showed that the blends had certain compatibility, and the interfacial bonding of PLA/Ethylene/butyl methacrylate/Glycidyl Methacrylate Terpolymer (GEBMA) blend was the best. With addition of the toughening agents, all blends showed improvement of the tensile and impact toughness both at room temperature and low temperature.
View Article and Find Full Text PDFPoly(L-lactic acid) (PLLA) blends with excellent low-temperature toughness and strength were prepared by melt compounding with acrylic ester based impact resistance agent (AEIR). The morphology, thermal properties, mechanical properties and biodegradability of the blends were investigated. Morphology observations revealed the blend was immiscible but had good compatibility with the dispersed phase size of about 200-300 nm.
View Article and Find Full Text PDFThe poly(lactic acid) (PLA) composites with the silane coupling agent treated basalt fiber (SBF) and basalt fiber powder (SBFP) were prepared. The crystalline morphology, mechanical properties, and heat resistance of PLA/SBF/SBFP composites were investigated. The results indicated that SBF or SBFP not only acted as heterogeneous nucleating agents for PLA crystallization but also improved the mechanical properties and heat resistance of PLA.
View Article and Find Full Text PDFA sensitive and robust method has been developed using an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) assay to quantify Tat-K13, a novel interfering peptide for the treatment of ischemic stroke, in human plasma. Automated solid-phase extraction on a Waters Oasis WCX (30 μm, 10 mg) 96-well plate was used to extract Tat-K13 from human plasma and the extracts were separated on a Waters Acquity CSH column (2.1 × 50 mm i.
View Article and Find Full Text PDFA comparative study on interfacial crystallization of poly(l-lactic acid) (PLLA) with different stereoregularity (PLLA2003D 96.0%, PLLA4032D 98.5%, and PLLA290 99.
View Article and Find Full Text PDFThe super toughed poly(l-lactic acid) (PLLA) blends with various content of Ethylene/butyl methacrylate/Glycidyl Methacrylate Terpolymer (GEBMA) were prepared by melt compounding. The blend was an immiscible system but had good compatibility due to the chemical reaction between the epoxy groups of GEBMA and the end group of PLLA during the blending process. The addition of GEBMA suppressed the cold crystallization and non-isothermal melt crystallization of PLLA.
View Article and Find Full Text PDFIn this work, rare earth europium was combined with different organic ligands to obtain two kinds of rare earth conversion agents, Eu(DBM)CPC and Eu(TTA)(TPPO). Two kinds of conversion films were successfully prepared by combining them with polylactide and poly(butylene adipate-co-terephthalate). Results showed that the film has excellent light conversion ability and high color purity, and rare earth complexes improved melt flowing property and decreased melt viscosity of blend.
View Article and Find Full Text PDFJ Med Chem
April 2015
Neuroactive steroids (NASs) have been shown to impact central nervous system (CNS) function through positive allosteric modulation of the GABA(A) receptor (GABA(A)-R). Herein we report the effects on the activity and pharmacokinetic properties of a series of nor-19 pregnanolone analogues bearing a heterocyclic substituent at C-21. These efforts resulted in the identification of SGE-516, a balanced synaptic/extrasynaptic GABA(A) receptor modulator, and SGE-872, a selective extrasynaptic GABA(A) receptor modulator.
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