Copolymerization of liquid sulfur with certain olefinic systems and structure‐property studies on the polymeric materials

Abstract

Liquid sulfur–olefinic reactions at 140°C forming crosslinked polysulfide polymers have been investigated. A systematic approach to the characterization and some structure–property studies on these new polymeric materials has been presented. The olefinic systems of interest are endo‐and exo‐dicyclopentadiene and an oligomeric alkenyl polysulfide. Equimolar S8–olefinic system copolymers are amorphous and they show no tendency for sulfur crystallization. A correlation has been drawn between chemical structure and glass transition temperature of the copolymers and terpolymers. Mechanical properties and, in particular, chemical stress relaxation of the crosslinked polysulfide polymers have been investigated.

The Chemistry of Organic Polysulfanes R−Sn−R (n > 2)

“…endo-DCPD reacts more slowly with liquid sulfur at 140 °C than exo-DCPD, while the cyclic trisulfanes of endo-and exo-DCPD react at almost the same rate with liquid sulfur at 140 °C. 386,387 The structures of DCPD-S 3 , DCPD-S 5 , and the likely structure of the low-molecular mass polymer are shown in Figure 8. Polysulfanes prepared from DCPD have also been used as sulfur donors in the sulfur-vulcanization of rubber; 388 The reaction of styrene with liquid sulfur also results in the formation of polymeric polysulfanes.…”

Inverse vulcanization of elemental sulfur and styrene for polymeric cathodes in Li‐S batteries

“…The inverse vulcanization process is essentially a bulk free radical copolymerization of unsaturated comonomers in liquid sulfur, or sulfur containing solutions. The free radical copolymerization of S 8 with vinylic comonomers, such as, acrylates, vinyl acetates, tetrafluoroethylene, 2‐chloroprene, 1,3‐butadiene, cyclododeca‐1,5,9‐triene, cyclohepta‐1,3,5‐triene, cycloocta‐1,3‐diene, cyclohexene, 1‐methylcyclohexene, norbornene, dicyclo‐pentadiene, tricyclopentadiene, limonene, 6‐dimethylocta‐2,4,6‐triene, 7‐methyl‐3‐methyleneocta‐1,6‐diene, 3,7‐dimethylocta‐1,6‐diene, and 2,6‐dimethylhepta‐1,5‐diene has been investigated in the 1960s and 1970s; however, the formation of low molar mass oligomeric materials were primarily observed from these systems. Of these early studies, the work on the copolymerization of S 8 with styrene was of particular interest for the preparation of polymeric cathode materials for Li‐S batteries due to the very low cost styrene and widespread industrial use of styrenic comonomers for free radical polymerizations.…”

Preparation and characterization of a new cement-based composite with sulfur polymer

“…Then, 30 mL of DCPD oligomer was added into the molten sulfur and 3.0 mL of pyridine was added. The reaction between DCPD and sulfur was promoted by freeradical chain process at the low temperature of about 140 C, 29,30 while the sulfur molecules were intrinsically polymerized above 159.4 C. 31,32 The 3.0 mL of pyridine, which acts as a co-solvent of the sulfur and DCPD, was added into the liquid mixture of molten sulfur and DCPD to stabilize the exothermic reaction. Aer completion of the reaction, the mixture became a single-phase solution to be used for the bulk copolymerization process.…”