Block Copolymers as Homogenizing Agents in Blends of Amorphous and Semicrystalline Polymers

1985 ◽  
pp. 447-448
Author(s):  
Michael A. Drzewinski
1980 ◽  
Vol 3 (5) ◽  
pp. 301-304 ◽  
Author(s):  
R. J. Gaylord ◽  
D. J. Lohse ◽  
C. M. Guttman ◽  
E. A. DiMarzio

1992 ◽  
Vol 264 ◽  
Author(s):  
Hugh R. Brown

AbstractThe adhesion of glassy or semicrystalline polymers to themselves or to other polymers is often poor. Polymers gain their strength from the mechanical interconnection between different chains. This interconnection can occur either by the use of long chains that entangle with each other or by chemically joining the chains by cross-linking. A strong polymer-polymer interface is crossed by many chains that are mechanically coupled into the material on both sides of the interface. For cross-linked systems these coupling chains must be cross-linked into both sides. If the polymers are not crosslinked, the coupling chains are formed by interdiffusion or welding. Interdiffusion can occur only if the system is heated to a temperature that allows significant chain mobility and if the interconnecting chains are sufficiently miscible in both polymers. For some systems, such as polyimides, the mobility required can either be generated by just part curing the materials before joining or by reversing the completed cure of a thin surface layer before joining and completing the cure. The interconnecting chains do not have to be the same material as the polymers being joined and, for joining dissimilar polymers, can be block copolymers where each block is miscible in just one of the relevant polymers.


2002 ◽  
Vol 724 ◽  
Author(s):  
Elizabeth R. Wright ◽  
R. Andrew McMillan ◽  
Alan Cooper ◽  
Robert P. Apkarian ◽  
Vincent P. Conticello

AbstractTriblock copolymers have traditionally been synthesized with conventional organic components. However, triblock copolymers could be synthesized by the incorporation of two incompatible protein-based polymers. The polypeptides would differ in their hydrophobicity and confer unique physiochemical properties to the resultant materials. One protein-based polymer, based on a sequence of native elastin, that has been utilized in the synthesis of biomaterials is poly (Valine-Proline-Glycine-ValineGlycine) or poly(VPGVG) [1]. This polypeptide has been shown to have an inverse temperature transition that can be adjusted by non-conservative amino acid substitutions in the fourth position [2]. By combining polypeptide blocks with different inverse temperature transition values due to hydrophobicity differences, we expect to produce amphiphilic polypeptides capable of self-assembly into hydrogels. Our research examines the design, synthesis and characterization of elastin-mimetic block copolymers as functional biomaterials. The methods that are used for the characterization include variable temperature 1D and 2D High-Resolution-NMR, cryo-High Resolutions Scanning Electron Microscopy and Differential Scanning Calorimetry.


Author(s):  
Mark J. Newman ◽  
Jeffrey K. Actor ◽  
Mannersamy Balusubramanian ◽  
Chinnaswamy Jagannath
Keyword(s):  

2019 ◽  
Author(s):  
Jacob Ishibashi ◽  
Yan Fang ◽  
Julia Kalow

<p>Block copolymers are used to construct covalent adaptable networks that employ associative exchange chemistry (vitrimers). The resulting vitrimers display markedly different nanostructural, thermal and rheological properties relative to those of their statistical copolymer-derived counterparts. This study demonstrates that prepolymer sequence is a versatile strategy to modify the properties of vitrimers.</p>


2018 ◽  
Author(s):  
Mustapha Abdu-Aguye ◽  
Nutifafa Doumon ◽  
Ivan Terzic ◽  
Vincent Voet ◽  
Katya Loos ◽  
...  

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