scholarly journals Phototocatalytic Lithography of Poly(propylene sulfide) Block Copolymers: Toward High-Throughput Nanolithography for Biomolecular Arraying Applications

Langmuir ◽  
2009 ◽  
Vol 25 (2) ◽  
pp. 1238-1244 ◽  
Author(s):  
Jane P. Bearinger ◽  
Gary Stone ◽  
Amy L. Hiddessen ◽  
Lawrence C. Dugan ◽  
Ligang Wu ◽  
...  
Keyword(s):  
Block Copolymers ◽  
High Throughput ◽  
Poly Propylene

scholarly journals New Biodegradable Poly(l-lactide)-Block-Poly(propylene adipate) Copolymer Microparticles for Long-Acting Injectables of Naltrexone Drug

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 852 ◽  
Author(s):  
Stavroula Nanaki ◽  
Athina Viziridou ◽  
Alexandra Zamboulis ◽  
Margaritis Kostoglou ◽  
Georgios Z. Papageorgiou ◽  
...  
Keyword(s):  
Block Copolymers ◽  
Drug Release ◽  
Amorphous State ◽  
Copolymer Composition ◽  
Polymeric Matrices ◽  
Release Studies ◽  
Biodegradable Poly ◽  
Long Acting ◽  
Poly Propylene ◽  
Tga And Dsc

In the present study, novel block copolymers of poly(l-lactide)-block-poly(propylene adipate) (PLLA-b-PPAd) were synthesized in two ratios, 90/10 and 75/25 w/w and were further investigated as long-acting injectable (LAI) polymeric matrices in naltrexone base microparticle formulations. The synthesized polymers were characterized by 1H-NMR, 13C-NMR, FTIR, XRD, TGA and DSC. NMR and FTIR spectroscopies confirmed the successful synthesis of copolymers while DSC showed that these are block copolymers with well-defined and separated blocks. Microparticles were prepared by single emulsification method and were further characterized. Nanoparticles in the range of 0.4–4.5 μm were prepared as indicated by SEM, with copolymers giving the lowest particle size. By XRD and DSC it was found that naltrexone was present in the amorphous state in its microparticles. Dissolution study showed a drug release extending over seven days, indicating that these novel PLLA-b-PPAd copolymers could be promising matrices for naltrexone’s LAI formulations. It was evidenced that drug release depended on the copolymer composition. Model release studies showed that drug release is controlled by diffusion.

Oxidation-responsive polyether block copolymers lead to non-ionic polymer surfactants with multiple amine N-oxides

2019 ◽  
Vol 10 (13) ◽  
pp. 1569-1574 ◽  
Author(s):  
Jan Blankenburg ◽  
Martin Stark ◽  
Holger Frey
Keyword(s):  
Block Copolymers ◽  
Propylene Oxide ◽  
Tertiary Amines ◽  
Ionic Polymer ◽  
Polymer Surfactants ◽  
Poly Propylene

Oxidation of tertiary amines leads to multiple amine N-oxide moieties and a highly polar polyether structure. Combination with the apolar poly(propylene oxide) affords unusual surfactants.

Elastomer Blends

1974 ◽  
Vol 47 (3) ◽  
pp. 481-510 ◽  
Author(s):  
P. J. Corish ◽  
B. D. W. Powell
Keyword(s):  
Block Copolymers ◽  
Propylene Oxide ◽  
Polymer Chains ◽  
Rubber Compound ◽  
Repeat Units ◽  
Rubber Compounds ◽  
Broad Concept ◽  
Poly Propylene ◽  
Styrene Butadiene ◽  
Composite Article

Abstract Mixtures are difficult to define within the range of materials employed in the rubber and plastic industries. A composite article such as a tire is a mixture of wire (metal), textile cord (organic fiber), and rubber compounds. The rubber compound itself is a mixture of elastomer, filler, and, usually, extender. Moreover, the elastomer may be a mixture of two or more rubbers. On a smaller scale, the elastomer may contain ‘blocky’ segments or crystalline portions along the polymer chains which act as ‘reinforcing’ agents or stiffeners. These may be similar to the repeat units of the elastomeric part, e.g., isotactic—atactic block copolymers of poly(propylene) or poly(propylene oxide); or different from it, as in the stereo block styrene—butadiene thermoplastic copolymers. Two types of elastomer may of course, be copolymerized or one elastomeric type may be grafted onto another. Furthermore, certain catalysts could cause simultaneous homopolymerization of two monomers. All the foregoing systems are different facets of the broad concept of blends, but some selection is obviously needed. In this review, most emphasis will be placed on elastomer—elastomer blends including their preparation from the constituent elastomers. Reference will be made to elastomer—plastic blends prepared from separate materials and by block/graft type reactions. Blends of one plastic with another lie outside the scope of this review.

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