نتایج جستجو برای: hyperbranched copolymers
تعداد نتایج: 9697 فیلتر نتایج به سال:
Due to the low solubility of poly(glycolic acid) (PGA), its use is generally limited to the synthesis of random copolyesters with other hydroxy acids, such as lactic acid, or to applications that permit direct processing from the polymer melt. Insolubility is generally observed for PGA when the degree of polymerization exceeds 20. Here we present a strategy that allows the preparation of PGA-ba...
We report results from Brownian dynamics computer simulations of systems comprised by two terminally charged hyperbranched molecules preferentially branched in the periphery, with an oppositely charged linear chain of varying length. Comparison of the findings from the present study to stoichiometric counterparts and to analogous dendrimer-based complexes, reveal that the presence of the second...
In this study, poly carbonate (PC) and poly (ethylene terephthalate) (PET) were reactive melt-blended under two different conditions to produce PC/PET copolymers. For each condition, samples were taken at specified mixing times representative a specific structure of copolymers and each one employed to physically compatibilize a PC/PET blend with a fixed composition. Reactive blending and copoly...
In order to improve the water-solubility of curcumin, the complex between curcumin and hyperbranched poly(amide-ester) was formed by dispering the solid curcumin in hyperbranched poly(amide-ester) aqueous solution. The interaction process was characterized by UV-vis absorption spectroscopy, Fluorescence quenching method, Fourier transformation-infrared spectroscopy, thermogravimetric analysis. ...
Electron capture dissociation (ECD) of doubly protonated hyperbranched polyesteramide oligomers (1100-1900 Da) was examined and compared with the structural information obtained by low energy collisionally activated dissociation (CAD). Both the ester and amide bonds of the protonated species were cleaved easily upon ECD with the formation of odd electron (OE(.+)) or even electron (EE(+)) fragme...
The development of DSM’s Hybrane hyperbranched poly(ester amides) is described. The monomer (1) for the hyperbranched polyester is obtained from the reaction of a cyclic anhydride with diisopropanol amine, yielding a tertiairy amide with one COOH and two OH groups. Polycondensation takes place via an oxazolinium intermediate in bulk at relatively mild conditions in the absence of catalyst. The ...
Hyperbranched polymer (poly-1a) with sulfonic acid groups at the end of chains was successfully synthesized. Interpenetration reaction of poly-1a with a hyperbranched polymer with acryloyl groups at the end of chains (poly-1b) as a cross-linker afforded a tough electrolyte membrane. The poly-1a and the resulting electrolyte membrane showed the ionic conductivities of 7x10 and 8x10 S/cm, respect...
A new family of amine- and ammonium-terminated hyperbranched polycarbosilanes (PCS) and dendrimers has been synthesized. The functionalization of a polycarbosilane matrix was carried out with peripheral allyl groups by two strategies in the case of PCS: 1) hydrosilylation of allyl amines with PCS containing terminal Si-H bonds, or 2) hydrosilylation of PCS-allyl with an aminosilane. Dendrimers ...
Convergent syntheses of polyglycerol hyperbranched polymers containing fluorescent labels (fluorescein or perylene diimide (PDI)) at their core are presented. The hyperbranched polyglycerol (HPG) precursors were synthesized using a one step polymerization reaction wherein the initiator leaves a single reactive group for dye functionalization. For further site isolation, allylated HPG was synthe...
A series of water soluble PEG based hyperbranched polymers were successfully synthesized by homopolymerization of poly(ethylene glycol) diacrylate (PEGDA) (Mn 1⁄4 575 and 700 g mol 1 respectively) via vinyl oligomer combination. The homopolymerization of diacrylate macromers underwent a slow vinyl propagation combined with a polycondensation by coupling of reactive oligomers. At a high initiato...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید