A ternary system for delayed curing inverse vulcanisation.

Completion of inverse vulcanisation reactions leads to a crosslinked insoluble polymer, but insufficient reaction allows phase separation of the sulfur and organic corsslinkers. A ternary co-polymer system allows delayed curing to be used, keeping the pre-polymer stable, homogeneous, and ready to be set into its final form when and where needed, allowing greater opportunities for practical production

Towards a Dynamical Solution of the Strong CP Problem

It is argued that QCD might solve the strong CP problem on its own. To test this idea, a lattice simulation suggests itself. In view of the difficulty of such a calculation we have, as a first step, investigated the problem in the $CP^3$ model. The $CP^3$ model is in many respects similar to QCD. In this talk I shall present some first results of our calculation. Among other things it is shown that the model has a first order deconfining phase transition in $\theta$ and that the critical value of $\theta$ decreases towards zero as $\beta$ is taken to infinity. This suggests that $\theta$ is tuned to zero in the continuum limit.Comment: 8 pages, postscript file, DESY 94-031, HLRZ 94-13, talk given at the Third KEK Topical Conference on CP Violatio

Crosslinker Copolymerization for Property Control in Inverse Vulcanization.

Sulfur is an underused by-product of the petrochemicals industry. Recent research into inverse vulcanization has shown how this excess sulfur can be transformed into functional polymers, by stabilization with organic crosslinkers. For these interesting new materials to realize their potential for applications, more understanding and control of their physical properties is needed. Here we report four new terpolymers prepared from sulfur and two distinct alkene monomers that can be predictively tuned in glass transition, molecular weight, solubility, mechanical properties, and color

Dark Sulfur: Quantifying unpolymerized sulfur in inverse vulcanized polymers

Elemental sulfur is produced as a by-product of the refining process of the petrochemicals industry. This generates an excess of sulfur each year that currently goes unused. A process known as inverse vulcanization allows polymeric mate-rials to be formed from elemental sulfur, stabilised with organic comonomers or crosslinkers. The resultant high sulfur content polymers have shown many interesting and unique properties, and are being investigated for a growing number of applications. However, the techniques regularly used to determine if free unreacted sulfur, as S8, remains in the mate-rials only detect the crystalline, and not the amorphous form. Here is presented a detailed study on the identification and quantification of free amorphous sulfur present within inverse vulcanized polymers, both immediately after synthesis and after a period of aging, in which free sulfur is shown to increase over time. The potential for post-aging regeneration, by applying heat to stimulate homolytic disulphide cleavage, is also investigated

Macroporous sulfur polymers from a sodium chloride porogen—a low cost, versatile remediation material

Sulfur has an affinity for Hg. By polymerising and crosslinking elemental sulfur with dienes, it can be formed into a stable polymer. A salt template method to create porosity in these polymers is reported, and shown to improve the Hg capture.</p