Dual temperature curable silicone compositions, methods of manufacture, and articles prepared therefrom

A method of fully curing a dual temperature curable silicone composition to form an article, the method comprising:

• providing a silicone composition, wherein the silicone composition comprises:
• 100 parts by weight of a vinyl silicone of Formula I
• RB[Si(R1R2)—O]—[(Si(R3R4)—O)]n—[Si(R5R6)—O)]m—Si(R1R2)—RA (Formula I)
• wherein
• n has an average value of 1 to 200,
• m has an average value of 5,000 to 20,000,
• RA, RB, R1, R2, R3, R4, R5 and R6 are each independently a C1-C6 alkyl group;
• and
• at least one of RA, RB, R3 and R4 has the formula —CH═CRFRG, where RF and RG are each independently hydrogen or a C1-C6 alkyl group;
• 0.05-10 parts by weight of a silicone hydride-containing crosslinker;
• a platinum-containing catalyst;
• and
• 0.2-5 parts by weight of a peroxide catalyst, wherein the platinum-containing catalyst and peroxide catalyst are present in a weight percent ratio of 0.001:1 to 0.01:1;
• shaping the silicone composition to provide a shaped silicone composition;
• exposing the shaped silicone composition to a first temperature to activate the platinum catalyst but not the peroxide catalyst, to form a shaped, semi-cured, article;
• and
• heating the shaped, semi-cured article to a second temperature sufficient to activate the peroxide catalyst, to form a fully cured article.