硼酯交联增强聚合物的制备和表征.

张新慧; 白 静; 史子兴; 钟蔚华

A series of copolymers with β-diketone groups (PABn) were synthesized by free radical copolymerization using 2-(acetoacetyloxy) ethyl methacrylate (AAEM) and N-butyl acrylate (BA) as monomers, and azobisisobutyronitrile (AIBN) as the initiator. Then the adjacent dihydroxyl groups were attached to the copolymers to give rise to PABn-2OH via the reaction between β-diketone and primary amines. Finally, with the addition of boric acid, a series of crosslinked copolymers (PABn- 2OH-B) were obtained via boron esterification. The mechanical properties of PABn-2OH and PABn-2OH-B samples and the influence factors were studied by tensile measurements and dynamic mechanical tests. It was shown that the compositions of copolymer, the content of adjacent dihydroxyl and crosslinking density presented significant impacts on the mechanical performances. The presence of dihydroxyl groups can not only effectively improve the mechanical properties via the hydrogen bonds among copolymers, but also provide accesses for boric acid into the polymer network to form crosslinked inorganic-organic hybrids connected by boron esterification bonds. In this context, soaking of PABn-2OH in aqueous solution of boric acid could form boron ester cross-linking, resulting in significant mechanical enhancement with only 1% mass fraction of boron in PABn-2OH-B samples, which was analogous to the mineralization process of mineral elements in plants. Inspired by the phenomenon in nature, the mechanical properties of copolymer were effectively tailored via controlling the content of hydroxyl groups and their reactions with boric acid. Furthermore, the boron ester bonds were reversible in acid and base solution, and various shape transformations could be realized via controlling the environmental pH.

BORIC acid; POLYMER networks; IMPACT (Mechanics); MONOMERS; PLANT assimilation; BORON isotopes; IMPRINTED polymers; DIBLOCK copolymers

Journal of Functional Polymers, 2019, Vol 32, Issue 4, p479

1008-9357

Academic Journal

10.14133/j.cnki.1008-9357.20181203001