Related Experiment Video
Updated: May 30, 2025
05:48
Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes
Published on: November 21, 2017
8.0K
X-Ray Shielding Polymer Based on Sequential Polycondensation of BiPh3 and Carboxylic Acids and Radical Polymerization
Bungo Ochiai1, Ryo Kamiya1, Yoshimasa Matsumura2
1Graduate School of Science and Engineering, Yamagata University, Yonezawa 990-8510, Japan.
Polymers
|January 25, 2025
Summary
New transparent polymer films offer effective X-ray shielding. These films utilize bismuth carboxylate prepolymers and demonstrate high transparency and adjustable shielding capabilities, making them suitable for advanced applications.
Area of Science:
- Materials Science
- Polymer Chemistry
- Medical Physics
Background:
- Traditional X-ray shielding materials often lack transparency and flexibility.
- Developing advanced materials for radiation protection is crucial in medical and industrial settings.
Purpose of the Study:
- To develop novel transparent polymer films with effective X-ray shielding properties.
- To investigate the relationship between bismuth content and X-ray shielding performance.
Main Methods:
- Bulk photo copolymerization of bismuth carboxylate prepolymers with N,N-dimethylacrylamide (DMAA).
- Synthesis of bismuth-containing prepolymers using BiPh3, 2-octenylsuccinic acid (OSA), and itaconic acid (IA).
- Characterization of film transparency, refractive index (nD), and X-ray shielding effectiveness.
Main Results:
- Successfully developed transparent X-ray shielding polymer films with high visible-light transparency.
- Achieved a high refractive index (nD) of 1.57.
- Demonstrated X-ray shielding ability that increases with bismuth content, reaching an aluminum equivalent of 0.80.
Conclusions:
- The developed bismuth-containing polymer films offer a promising combination of transparency and X-ray shielding.
- The material's properties can be tuned by adjusting bismuth content for specific applications.
- This innovation provides a new avenue for transparent radiation shielding materials.
Related Concept Videos
01:10Radical Chain-Growth Polymerization: Overview
2.4K
Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is...
2.4K
01:17Radical Chain-Growth Polymerization: Chain Branching
1.9K
The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical polymerization results in a low-density grade of polyethylene with a heavily branched skeletal structure. Here, the radical site abstracts hydrogen from the growing chain, and the radical site shifts from the end (a primary carbon center) to anywhere within the growing chain (a secondary carbon center). Consequently, the part of the chain from the...
1.9K
02:35Free-Radical Chain Reaction and Polymerization of Alkenes
7.7K
The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a repeating unit, while the terminal groups are considered insignificant. The average degree of polymerization represents the number of repeating units in the polymer molecule and is denoted by the subscript n.
7.7K
01:09Radical Chain-Growth Polymerization: Mechanism
2.5K
The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this...
2.5K
00:57Cationic Chain-Growth Polymerization: Mechanism
2.2K
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...
2.2K
01:20Anionic Chain-Growth Polymerization: Overview
2.1K
The polymerization process that involves carbanion as an intermediate is called anionic polymerization. It is also a type of addition or chain-growth polymerization. Anionic polymerization gets initiated by a strong nucleophile such as an organolithium or a Grignard reagent. The most commonly used initiator for anionic polymerization is butyl lithium. Monomers involved in anionic polymerization must possess a vinyl group bonded to one or two electron-withdrawing groups. For instance,...
2.1K