It is known in the art that certain polymer structures lead to particular characteristics in the resulting polymer. For example, the presence of long chain branching may improve certain polymer characteristics, such as processability and melt strength. The presence of long chain branching in a polymer is typically characterized by the occurrence of polymer moieties of a length greater than that of any olefin comonomer remnant attached to the main, backbone polymer chain. In prior art techniques, long chain branching may be generated in a polymer by incorporation of a vinyl-terminated macromer (either added or formed in situ during polymerization) either by action of the polymerization catalyst itself or by the use of a linking agent. These methods generally suffer from incomplete incorporation of the vinyl-terminated macromer or linking moiety into the polymer, and/or a lack of control over the extent of long chain branching for given process conditions.
It is also known in the art that selective incorporation of particular moieties at the terminal ends of a polymer may produce polymers having particular physical properties or enable their use in specific applications. Significant research has been conducted into such syntheses and related strategies. Accordingly, controlling polymer structure is a topic of much research.
It is well known that acrylic polymers may be produced having a variety of different forms such as block copolymers, random polymers, and telechelic polymers. Acrylic polymers are used in a wide array of applications such as adhesive applications, and thus are of great interest to developers and formulators. Techniques are also known for placing functional groups at the ends of acrylic polymer chains in order to increase molecular weight. Modifying molecular weight and other characteristics of acrylic polymers enables adjustment of properties of adhesive compositions when such polymers are used therein. Although satisfactory in certain aspects, a significant need remains for producing polymers for adhesive formulations that have particular structures in order to provide desired end properties associated with the adhesive formed from the polymer.
As far as is known, currently known strategies do not enable precise placement of monomers with functional groups in particular regions of a polymer. Moreover, currently known strategies do not provide polymers having particular concentrations or loading densities of functional groups in select regions of the polymers, and particularly polymers having precise weight ratio concentrations of functional groups in different regions of the polymers. Accordingly, a need exists for such methods and for polymers having ordered architectures produced using such methods.