Posts

Excited Triplet States of Organic Molecules and Reactive Free Radicals in Polymers

Image
                                             JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract The mini-review is devoted to the recent investigation the role of cage effect during photopolymerization. Benzophenone was selected as a photoinitiator of polymerization. Introduction Free-radical photopolymerization (UV-cure) of organic coatings is a very important process that has been used for more than half a century. Academic and industrial researchers study the basics of this complex process [1-4] In this mini review we will briefly consider the important role of low MW free radicals of photoinitiators (PIs) and the excited triplet states of PIs in photopolymerization. On the contrary, residual PIs in the cured coatings and other low MW photoreactive species in the cured coatings/polymers lead to a negative effect: photodecomposition of polymers outdoo...

Recent Advances in the Synthesis and Analysis of Polyamide 6 and Products therefrom: From Polymerization Chemistry of εcaprolactam to Thermoplastic Resin Transfer Moulding (t-rtm)

Image
                                   JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract Significant research and developments are taking place in the field of synthetic polyamides (Nylons). One of the most investigated members of this family of polymers is poly (ε-caprolactam) (PCL, Polyamide 6, PA6, Nylon 6). Herein, a brief overview will be presented on the major recent advancements in the anionic ringopening polymerization (AROP) of ε-caprolactam (CL) by the initiating combinations of metal lactamates and carbamoylcaprolactams and by some other initiating systems, e.g. protected N-heterocyclic carbenes , NaHMDI and σ-borane-barium complexes. The in situ polymerization of CL in the presence of additives, such as flame retardants, reinforcing agents and fillers, is also discussed. Examples are presented on the determination of the molecular weight distributions (MWD) and average...

The Evaluation of Poly(imide) Siloxane to use in Biomedical and Radiotherapy Applications

       JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract Poly(imide) siloxane encourages new research studies that offer innovative and comprehensive industrial areas, experimental approaches and their innovative products. Poly(imide) siloxane covers the studies in fundamental organic polymer chemistry and physical organic chemistry, noval researches on membranes and interfaces. The possible applications of the poly(imide) siloxane as shielding material include facilities such as biological shielding at nuclear medicine departments. Keywords:  Copolymers; Poly(imide) siloxane; Radiation Introduction Polymer based drug gene delivery systems with critical structural features at the nanometere scale have attracted immense interest. Besides, polymer applications to drug/gen delivery has offered unprecedented opportunities for the creation of a variety of polymeric structures. The drugs including nanocarriers can be derived from poly(imide) silo...

The Explanation of Magnetic Metal Carbon Mesocomposites Synthesis Peculiarities by Means of Mesoscopics Notions

Image
     JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract Mechanism of mesoparticles modification reactions are considered with the application of such notions as charges quantization, phase coherence, interference and annihilation. On the base of theoretical Mesoscopics ideas the formation of covalent bonds because of the interference of negative charges quants in modification reactions is discussed. The hypothesis about possibility of annihilation at the interaction of positive and negative charges quants in redox processes is presented. The magnetic metal carbon mesoscopic composites synthesis (for example, initial metal carbon Mesocomposites) is realized by mechanochemical method at the grinding of metal oxides microscopic particles with polyvinyl alcohol macromolecules. Then in the result the Copper or Nickel Carbon mesocomposites which have the following atomic magnetic moments: for Copper – 1,3 μB, for Nickel – 1,8 μB are obtained. The investigat...

Fast Triggered Controllable Electrically Actuated Shape Memory Epoxy: Graphene oxide Nanocomposites

Image
       JUNIPER PUBLISHERS-   ACADEMIC JOURNAL OF POLYMER SCIENCE Abstract Shape memory polymers (SMPs) are the new class of smart fascinating polymer materials with different potential applications. This research work aims to present systematic investigations of electrically actuated shape memory (EASM) properties at different electric voltage of epoxy polymer filled with 0.1 to 0.4 wt. % of Graphene (GO) to develop SMPs nanocomposites. EASM effect and surface morphology functional analysis of composites were observed after EASM characterization by Field Emission-Scanning Electron Microscopy (FE-SEM) and Fourier Transform Infrared Spectroscopy (FT-IR). 0.4 wt. % addition of GO showed highest shape recovery at 180 S, 140 S and 95 S for 40 V, 60 V and 80 V respectively. These results suggest that GO could be promising materials for electrically actuated shape memory applications. Keywords:  Graphene Oxide; Epoxy; Smart Polymer; Shape Memory; Polymer Nanocompo...