Highly functionalized polycyclosiloxanes and their polymerization into thermally reversible living rubbers

A polycyclosiloxane according to formula II, ##STR17## wherein R is oxygen, C.sub.1 to C.sub.12 straight or branched chain alkylenyl,

• a is 2 to 20,
• c is 1 to 3, and
• d is zero to 100,
• provided a may not be 3 when c is 1.

A polycyclosiloxane according to formula III, ##STR18## wherein R is oxygen, or C.sub.1 to C.sub.12 straight or branched chain alkylenyl,

• a is 2 to 20,
• c is 1 to 3,
• d is zero to 100 and
• e is 1 to 3.

A polycyclosiloxane according to formula IV, ##STR19## wherein R is oxygen, or C.sub.1 to C.sub.12 straight or branched chain alkylenyl,

• a is 2 to 20,
• f is 1 or 2,
• g is 1 to h, and
• h is 3 to 20,
• provided f and g are not both 1.

A polycyclosiloxane according to formula V, ##STR20## wherein R is oxygen, or C.sub.1 to C.sub.12 straight or branched chain alkylenyl,

• a is 2 to 20,
• j is 1 to 2,
• m is 1 to 100,
• X is hydrogen, C.sub.1 to C.sub.12 straight or branched chain aklyl, C.sub.1 to C.sub.12 straight or branched chain alkoxy, phenyl vinyl or Z, wherein Z is a cyclic moiety according to formula (VII) ##STR21## where a and R are defined as above, provided:
• when
• X is Z:
• k is 1 to 100 and
• n is 1 to 100;
• when
• X is other than Z:
• k is 1 to 100 and
• n is 1 to 100, except that when k is 1 or 2, n must be greater than 2, and when n is 1 or 2, k must be greater than 2;
• Y is methyl or Z;
• p is 1 or 2;
• q is zero to r;
• r is 1 to 18;
• and
• t is zero to 100.

A polycyclosiloxane according to formula VI, ##STR22## wherein R is oxygen, or C.sub.1 to C.sub.12 straight or branched chain alkylenyl,

• a is 2 to 20,
• Y is methyl or Z, wherein Z is a cyclic moiety according to formula (VII) ##STR23## wherein a and R are defined as above, p is 1 or 2,
• q is zero to r,
• r is 1 to 18, and
• t is zero to 100, provided, that when p is one, R may not be CH.sub.2 or CH.sub.2 CH.sub.2.