Synthesis And Study Of Polydimethylsiloxane With A Diol End Group

Polydimethylsiloxane (PDMS) possess many unique properties, such as the extremely low glass transition temperature, low surface tension and surface energy, and low solubility parameter, it is the most important in terms of commercial applications. Block and graft copolymers consisting of PDMS as a segment component have gained increasing attention owing to the unique properties of these hybrid polymers both in bulk and at the surface. For the former, many researches have been focused on block copolymerization modification while in contrast relatively scare attention was put on graft copolymerization modification, especially the synthesis and characterization of PDMS with a diol group at only one chain end have been rare.A novel synthesis path for the monotelechelic polydimethylsiloxane with a diol-end group is described in this paper. A series ofα-butyl-omega-{3-[2-hydroxy-3- (N-methyl-N-hydroxyethylamino)propoxy]propyl}polydimethylsiloxane, which can form polyurethane-polysiloxane graft copolymer, were synthesized via anionic ring-opening polymerization, hydrosilylation, and epoxy addition using hexamethylcyclotrioxysilane, ally glycidyl ether (AGE), N-Methylmonoethanolamine (MMEA) as starting materials. The targeted product and intermediate products in each process had been fully characterized by by FT-IR, NMR spectra, and gel permeation chromatography. The results showed that each step was successfully carried out and the targeted products were accessed in all cases. It is found that the materials used in the experiment are easy to attain, and the new approach is easier than those used in the previous studies , which involve hydroxyl protection and deprotection.In order to certify epoxy addition, using AGE and MMEA as materials. The product had been fully characterized by FT-IR, GC, 1H NMR and LC-MS. Trail the epoxy addition with the means of hydrochloric acid-acetone titration, and the results showed that increasing the ratio of materials and alcohol can shorten the time of reaction, when he molecular weight ofα-butyl-omega-[3-(2,3-epoxypropoxy)propyl] polydimethylsiloxane is less than 2500.