The use of elemental sulfur as an alternative feedstock for polymeric materials

An excess of elemental sulfur is generated annually from hydrodesulfurization in petroleum refining processes; however, it has a limited number of uses, of which one example is the production of sulfuric acid. Despite this excess, the development of synthetic and processing methods to convert elemental sulfur into useful chemical substances has not been investigated widely. Here we report a facile method (termed 'inverse vulcanization') to prepare chemically stable and processable polymeric materials through the direct copolymerization of elemental sulfur with vinylic monomers. This methodology enabled the modification of sulfur into processable copolymer forms with tunable thermomechanical properties, which leads to well-defined sulfur-rich micropatterned films created by imprint lithography. We also demonstrate that these copolymers exhibit comparable electrochemical properties to elemental sulfur and could serve as the active material in Li-S batteries, exhibiting high specific capacity (823 mA h g(-1) at 100 cycles) and enhanced capacity retention.

Multi-stimuli responsive polymers – the all-in-one talents

The integration of several responsive moieties within one polymer yields smart polymers exhibiting a multifaceted responsive behaviour.

CO2-Responsive polymer materials

This paper reviews the chemical fundamentals of CO₂-responsive polymers as well as the latest reported “smart” material systems switched by CO₂.

Trends in polymeric shape memory hydrogels and hydrogel actuators

Recently, “smart” hydrogels with either shape memory behavior or reversible actuation have received particular attention and have been further developed into sensors, actuators, or artificial muscles.

Inverse vulcanization of elemental sulfur with 1,4-diphenylbutadiyne for cathode materials in Li–S batteries

High sulfur content copolymers were prepared via inverse vulcanization of sulfur with 1,4-diphenylbutadiyne (DiPhDY) for use as the active cathode material in lithium–sulfur batteries.

Efficient Multicomponent Postpolymerization Modification Based on Kabachnik-Fields Reaction

A Kabachnik-Fields postpolymerization modification reaction (KF-PMR) was conducted on poly(4-vinyl benzaldehyde) (poly(St-CHO)) with amines and phosphites. Successful KF-PMR was demonstrated by precise structural analysis of the obtained polymers and kinetic investigation of the KF-PMR processes, making it a powerful tool for postpolymerization modifications that lead to α-amino phosphonates as side groups.

Toward Self-Healing Hydrogels Using One-Pot Thiol-Ene Click and Borax-Diol Chemistry

Intrinsic self-healing soft materials such as hydrogels are especially promising for a variety of medical applications. Multistep preparation of starting functional polymer precursors and the expensive stock materials such as tetra-polyethylene glycol are one of the factors that limit the wider use of self-healing hydrogels. Herein, we reported a facile one-pot approach to prepare PEG based self-healing hydrogels from inexpensive commercially available components: polyethylene glycol diacrylate and dithiothreitol. For the first time, borax was used as the catalyst for a thiol-ene Michael-type polyaddition of PEG gels. Borax as the catalyst is quite efficient, allowing rapid gelation (from 40 s to 2 min) under ambient conditions and at room temperature. Essentially, as one catalyst, borax induces the formation of two classes of bonds, covalent thioether and transient boronate ester bonds, were formed at the same time. The storage modulus of the afforded PEG gel (87.5% water) reached up to 10⁴ Pa, making the mechanical performance comparable with permanently cross-linked PEG gels. Additionally, the dynamic nature of the boronate ester linkages imparts the gel with self-healing properties, and the obtained gels can be healed within 30 min without external stimulus. Further, the transparent hydrogel is pH and thermal responsive. We believe that the manifold impacts of borax can open a new route to prepare hydrogels with intriguing properties, which find potential application as gel sealant, biosensors, or regenerative medicines.