\”Macromolecules\”: Construction of multi-functional polysulfide urea synthesis strategy without catalytic
Polythiourethane is a typical sulfur-containing polymer, having a self-healing, high refractive index, a high dielectric constant, heavy metals and strong coordination ability and other special properties, is a class of polymer materials useful research value. Currently synthetic methods have been reported mainly diamine monomer with thiourea, phosgene, diisocyanates or elemental sulfur with the sulfur source monomeric diisocyanate, and the like reaction. These methods present several disadvantages such as: large toxic material, structural diversity restricted monomers, monomer synthesis complex, expensive and the like. Therefore, the development of green, low cost, pervasive strong polysulfide urea synthesis process is very scientific and industrial value.
- Figure 1. The polymerization reaction equation
2018, Tokyo University professor Takuzo Aida research team prepared a highly foreground polythiourethane polymer (the structure as shown in P1 1), taking into account the self-healing ability and excellent mechanical properties. Polymer system can be stretched to 393 ± 5%, an elastic modulus of about 1.4 GPa. And applying pressure to the section of the polymer at several tens of seconds and kept at room temperature by breaking the polymer material can be restored as ever, showing a perfect self-healing. The study broke the previous self-repairing material many bottlenecks problems, related papers published in the journal Science . However, this system uses expensive thiocarbonyl imidazole as a sulfur source and a complicated separation and purification of the polymer, resulting in a very high cost of synthesis of the polymer, limiting its application.
Of the polymer P1 were NMR, mass spectrometry time of flight matrix assisted characterized, defined its backbone structure. The researchers then examined polythiourethane P1 is self-healing. 2, is first prepared by casting rectangular sheets P1. After the sheet was cut into two pieces, the two fragments attached to the mouth of the extrusion is placed 30 seconds for 10 minutes, the sheet was found stable after healing subjected to a load of 200g. Above show that, Pl may be extruded through rt for rapid self-healing, healing after mechanical strength can still meet the requirements.
The first reported work copolymerizing at room temperature, in air, without a catalyst and carbon disulfide diamine, efficient and convenient, economically prepared polythiourea structural diversity. The synthetic strategy mild conditions, low cost, wide range of monomers suitable. The researchers hope that this work will provide a convenient method for the synthesis of structural and functional diversity polythiourethane a simple and feasible for the majority of the material scholars. This achievement with Catalyst-Free Construction of Versatile and Functional CS2-Based Polythioureas: Characteristics from Self-Healing to Heavy Metal Absorption was published on Macromolecules. First author Changshu Institute of Technology and the University of Suzhou joint training Master Wu Shuang, Corresponding Author Luo Ming teacher. Article link: https: //pubs.acs.org/doi/10.1021/acs.macromol.9b01811# References:  Science, 2018, 359, 72-76, DOI: 10.1126 / science.aam7588