scholarly journals Boron–nitrogen main chain analogues of polystyrene: poly(B-aryl)aminoboranes via catalytic dehydrocoupling

2017 ◽  
Vol 53 (85) ◽  
pp. 11701-11704 ◽  
Author(s):  
Diego A. Resendiz-Lara ◽  
Naomi E. Stubbs ◽  
Marius I. Arz ◽  
Natalie E. Pridmore ◽  
Hazel A. Sparkes ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Main Chain ◽  
Aryl Amine ◽  
Amine Boranes ◽  
Boron Nitrogen

High molecular weight B-arylated polyaminoboranes are obtained via catalytic dehydropolymerisation of B-aryl amine–boranes and represent the first inorganic polystyrene analogues with a B–N main chain.

scholarly journals High molecular weight mechanochromic spiropyran main chain copolymers via reproducible microwave-assisted Suzuki polycondensation

2015 ◽  
Vol 6 (19) ◽  
pp. 3694-3707 ◽  
Author(s):  
Lukas Metzler ◽  
Thomas Reichenbach ◽  
Oliver Brügner ◽  
Hartmut Komber ◽  
Florian Lombeck ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Molar Mass ◽  
Main Chain ◽  
Microwave Assisted ◽  
Suzuki Polycondensation

Mechanochromic spiropyran main chain copolymers with high and reproducible molar mass can be made using microwave-assisted Suzuki–Miyaura polycondensation.

Poly(para-phenylene) ionomer membranes: effect of methyl and trifluoromethyl substituents

2021 ◽  
Author(s):  
Fanghua Liu ◽  
Jinju Ann ◽  
Junpei Miyake ◽  
Kenji Miyatake
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Main Chain ◽  
Polymer Main Chain ◽  
Ionomer Membranes ◽  
Sulfonated Poly

Sulfonated poly(para-phenylene)s with high molecular weight and membrane forming capability were obtained by use of the effect of methyl and trifluoromethyl substituents. The linearity of the polymer main chain decreased...

Autoxidative Degradation of Poly(phenylacetylene)

1993 ◽  
Vol 58 (11) ◽  
pp. 2651-2662 ◽  
Author(s):  
Jiří Vohlídal ◽  
Dana Rédrová ◽  
Marta Pacovská ◽  
Jan Sedláček
Keyword(s):  
Molecular Weight ◽  
Solid State ◽  
Induction Period ◽  
High Molecular Weight ◽  
Size Exclusion Chromatography ◽  
Main Chain ◽  
Size Exclusion ◽  
Cross Linking ◽  
Exclusion Chromatography ◽  
High Molecular Weight Poly

Autooxidative degradation of high molecular-weight poly(phenylacetylene) (PPhA) in solid state and in solution was studied using the size exclusion chromatography (SEC) and UV, IR, and EPR spectrometry. No degradation was observed on PPhA stored in vacuum, whereas the polymer exposed to air was found to degrade without any induction period. No evidence of a cross-linking of oxidized PPhA was observed. The degradation of PPhA was found to be: (i) practically non-influenced by an ambient, diffuse day-light; (ii) of the random type (i.e. each main-chain bond of PPhA has the same probability of being ruptured); and (iii) fast enough to influence the results of SEC measurements.

Preparation and Properties of High Molecular Weight Polyamic Ester Having a Cyclobutane Moiety in the Main Chain

1998 ◽  
Vol 10 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Masaki Hasegawa ◽  
Hirohiko Miura ◽  
Naoki Haga ◽  
Akira Hayakawa ◽  
Kiyoshi Saito
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Fractional Crystallization ◽  
Thionyl Chloride ◽  
Main Chain ◽  
Methanol Solution ◽  
The Other ◽  
Interfacial Polycondensation ◽  
Plane Symmetry ◽  
X Ray

Preparation and properties of the polyimide derived from cyclobutanetetracarboxylic dianhydride (CBDA) with diamines are investigated, focusing on the interfacial polycondensation of cyclobutanetetracarboxylic acid dimethylester dichloride (2a) with diamines. Dimethylester was conveniently prepared from CBDA by refluxing in methanol solution. Dimethylester consists of two regio isomers; one is α-type (1a) with centrosymmetry, the other is β-type (1b) with plane symmetry. Separation of the mixture into each of pure 1a and 1b was successfully performed by fractional crystallization. The structure of the first fraction is 1a, which was determined by x-ray crystal analysis. The second fraction was necessarily assigned to 1b. 1a was converted into 2a by the reaction of thionyl chloride. The interfacial polycondensation of 2a with diamines afforded a high molecular weight polyamic ester. Polyimide was obtained only by heating the polyamic ester to about 230–280 °C. The cyclobutane polyimide thus obtained was thermally stable up to 400 °C, and less stable under hydrolysis than polypyromellitic imide.

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