Melt Polymerization of Acrylamide Initiated by Nucleophiles: A Route toward Highly Branched and Amorphous Polyamide 3

Subduction zone or arc magmas are known to display a characteristic depletion of High Field Strength Elements (HFSE) relative to other similarly incompatible elements, which can be attributed to the presence of the accessory mineral rutile (TiO2) in the residual slab. Here we show that the partitioning behavior of vanadium between rutile and silicate melt varies from incompatible (∼0.1) to compatible (∼18) as a function of oxygen fugacity. We also confirm that the HFSE are compatible in rutile, with D(Ta)> D(Nb)>> (D(Hf)>/∼ D(Zr), but that the level of compatibility is strongly dependent on melt composition, with partition coefficients increasing about one order of magnitude with increasing melt polymerization (or decreasing basicity). Our partitioning results also indicate that residual rutile may fractionate U from Th due to the contrasting (over 2 orders of magnitude) partitioning between these two elements. We confirm that, in addition to the HFSE, Cr, Cu, Zn and W are compatible in rutile at all oxygen fugacity conditions.

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Study on Preparation of Star PLGA Cucurbitacin-Loaded Microsphere and its Propertities

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.884-885.630 ◽

2014 ◽

Vol 884-885 ◽

pp. 630-633

Author(s):

Yi Zhang ◽

He Wei Shao ◽

Yue Liu ◽

Xiao Yan Han

Keyword(s):

Drug Loading ◽

Star Polymer ◽

Cucurbitacin B ◽

Melt Polymerization ◽

Loading Amount ◽

Polymerization Method

The sealed tube melt polymerization method was employed to synthesize four-arm star polymer PLGA, by which drug-loaded microspheres for cucurbitacin B were prepared. Taking drug loading amount and entrapment effiency as the indicators, drug-loading formulation was optimized.

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Melt Polymerization of Adipic Anhydride (Oxepane-2,7-Dione)

Journal of Macromolecular Science Part A ◽

10.1080/10601329008544743 ◽

1990 ◽

Vol 27 (4) ◽

pp. 397-412 ◽

Cited By ~ 7

Author(s):

Ann-Christine Albertsson ◽

Stefan Lundmark

Keyword(s):

Melt Polymerization

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Synthesis of Poly(D,L-Lactic Acid-Co-Glucose) via Direct Polycondensation and its Characterization

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.80-81.370 ◽

2011 ◽

Vol 80-81 ◽

pp. 370-374 ◽

Cited By ~ 1

Author(s):

Shi He Luo ◽

Zhao Yang Wang ◽

Dong Na Huang ◽

Chao Xu Mao ◽

Jin Feng Xiong

Keyword(s):

Drug Delivery ◽

Lactic Acid ◽

Polylactic Acid ◽

1H Nmr ◽

Biodegradable Material ◽

Direct Polycondensation ◽

Carrier Material ◽

Melt Polymerization ◽

Drug Delivery Carrier ◽

Melt Polycondensation

Directly using cheap D,L-lactic acid (D,L-LA) and glucose (Glu) as starting materials, biodegradable material poly(D,L-lactic acid-co-Glucose) [P(D,L-LA-co-Glu)] was synthesized via melt polycondensation. When n(Glu) : n(D,L-LA) = 1:200, the appropriate synthetic condition is that: after 120 °C prepolymerization for 5 h, 160 °C melt polymerization catalyzed by w(SnCl2) = 0.5% for 5 h. P(D,L-LA-co-Glu) with different molar feed ratios were synthesized and characterized with [η], FTIR, 1H NMR, GPC and XRD. The Tg of all copolymer P(D,L-LA-co-Glu) was lower than that of homopolymer polylactic acid directly synthesized via melt polycondensation. The copolymers with Mw from 2,100 Da to 5,100 Da could meet the demand of drug delivery carrier material.

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