Posts

Showing posts from July, 2021

Sol-Gel Transition and Critical Gel in Vulcanization Reaction

Image
       JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract IThis study highlights how the transition from uncured to cured state in rubber is characterized by the formation of a particular network structure, so-called critical gel. Critical gel is formed in the first stages of vulcanization and is independent by the macromolecular structure and crosslinking. Keywords:  Curing cycle design; Under-cure phase; Spongelike region; Blowing point; Shrinkage; Critical Gel time; Elastomer; Compound; Viscoelasticity Introduction Vulcanization proceeds through three different stages, as shown in Figure 1. The first stage is characterized by an induction phase in which the reactions between the curatives and macromolecules of the polymeric matrix take place. In the second, commonly known as curing stage, cross-linking reactions between the macromolecular chains take place [1-2]. The initial sol-gel transition is characterized by the formation of a “critical gel” in which each polyme

Ion Exchange Membrane for Reverse Electrodialysis

Image
     JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract Ion exchange membranes (IEMs) are used for exchanging or removing ions from the solutions so that they are fabricated by polymers rather than metals or ceramics. When metal is in contact with the solutions, some reaction or corrosion occurs, and ceramic is difficult to use in membrane form because it is brittle. Also, normal metals and ceramics do not have high ion-exchange properties so that polymers are used widely as a host material of the IEM. The conventional IEMs are either layered membrane consisted of ion exchange material and support layer, and thick bulk membrane. There are no critical problems to use them for water treatment, but they are not suitable for electrochemical application such as reverse electrodialysis (RED). RED is a method of making electricity by sequential ion transport through semi-permeable membranes and electrochemical reaction at the electrode part so that the IEMs need to be develope

Happy Independence Day from Juniper Publishers!!!

Image
Independence Day- Juniper Publishers USA   Juniper Publishers Wishing You a very Happy US Independence Day