Encapsulated catalyst for one-part organopolysiloxane systems and methods related thereto

A curable organopolysiloxane composition comprising:

• (A) an organopolysiloxane represented by the average unit formula:
• RaSiO(4-a)/2
• wherein, R is a substituted or unsubstituted monovalent hydrocarbon group, and “a” is a number from 1.0 to 2.4, and having at least an average of 1.5 alkenyl groups in a molecule;
• (B) an organopolysiloxane having at least an average of 1.5 silicon-bonded hydrogen atoms in a molecule;
• (C) a particle comprising:
• a) a platinum-group catalyst;
• and
• b) a molecular weight controlled thermoplastic polymer having a Tg softening temperature of at least 20° C. selected from the group consisting of:
• i. polystyrene or a co-polymer thereof having a Mw from about 500 g/mol to about 30,000 g/mol, and a polydispersity index (PDI) of less than 2;
• ii. polymethylmethacrylate or a co-polymer thereof having a Mw from about 500 g/mol to about 30,000 g/mol, and a PDI of less than 2;
• and
• iii. polyacrylonitrile or a co-polymer thereof having a Mw from about 500 g/mol to about 30,000 g/mol, and a PDI of less than 2,
• wherein the platinum-group catalyst is fully encapsulated within the thermoplastic polymer;
• and
• (D) a filler or treating agent, or combination thereof.