Method for quantitative analysis of styrene microblock content

A method for synthesizing a copolymer, the method comprising the steps of:

• (i) polymerizing vinyl aromatic monomer and conjugated diene monomer to form a copolymer;
• (ii) obtaining a sample of the copolymer prepared by said step of polymerizing;
• (iii) determining the polystyrene microblock content the sample by (a) pyrolyzing the copolymer sample to form polymer fragments of the polymer sample;
• (b) analyzing the fragments to determine the relative amounts of styrene monomer fragments, styrene dimer fragments, and styrene trimer fragments, where the relative amounts of the fragments include the amount of any given fragment relative to the total of the monomer fragments, dimer fragments, and trimer fragments;
• and (c) using the relative amounts of the styrene monomer fragments, styrene dimer fragments, and styrene trimer fragments to predict the polystyrene microblock content from a mathematical model that is based upon the relative styrene monomer fragments, relative styrene dimer fragments, relative styrene trimer fragments, and microblock content of a copolymer having known microblock content;
• and
• (iv) optionally adjusting said step of polymerizing to adjust the microblock content of the copolymer.