Algebraic structures on modules of diagrams

There exists a graded algebra Λ acting in a natural way on many modules of 3-valent diagrams. Every simple Lie superalgebra with a nonsingular invariant bilinear form induces a character on Λ. The classical and exceptional Lie algebras and the Lie superalgebra D(2,1,α) produce eight distinct characters on Λ and eight distinct families of weight functions on chord diagrams. As a consequence we prove that weight functions coming from semisimple Lie superalgebras do not detect every element in the module A of chord diagrams. A precise description of Λ is conjectured.