Polymers are described that are prepared from di and mono-functional silicone and silane monomers of Formula 1 in which Y represents a direct bond or a oxy group; R1 represents an optionally substituted organo group with at least one double bond which optionally may be an activated unsaturated moiety such as a (meth)acrylate group: for example 1-n-propoxy(acrylate) or ethenyl; and R2 and R3 each separately, and independently within each optional repeat unit, represent an optionally substituted hydrocarbo, hydrocarbo(oxy), hydrosilico and/or hydrosilico(oxy) groups; or example, methyl; or trimethylsiloxy; R4 independently represents an optionally substituted organo group with at least one double bond (such as R1 above) an optionally substituted hydrocarbo, and/or hydrosilico group for example trimethylsilyl or ethenyl; and n is from about 0 to about 2000; preferably from about 1 to about 100, for example n is 1. Such polymer precursors can be used to prepare flow modifying agents, defoamers and/or pressure sensitive adhesives.