Compatibilization of polypropylene/poly(n‐butylacrylate) blend: Functionalization of the poly(n‐butylacrylate) phase by copolymerization

Abstract

SYNOPSISCompatibilization of a polypropylene (PP)/polybutylacrylate (PBuA) blend was studied, with the aim of achieving better adhesion at the interphase through modification of both the PP and PBuA phases. The compatibilization involved two separate stages: First, a small amount (2 and 5 mol %) of functional monomer copolymerizable with and soluble in BuA was added to the BuA initiator solution. Then, this solution was impregnated into PP pellets and polymerized inside the pellets by free-radical polymerization in a water suspension. The resulting blend was a thermoplastic elastomer consisting of PP as the matrix and functionalized PBuA as the partly crosslinked dispersed rubbery phase. The functionalities of the monomers were epoxy, oxazoline, hydroxyl, secondary amine, and carboxyl. In the second stage, two commercial graft copolymers of PP (PP grafted with either acrylic acid or maleic acid anhydride) were blended at the melt stage with the PP/ functionalized PBuA blend. Here, the compatibilizing reactions took place between the functionalized components of the blend. The compatilization reactions were detected by FTIR analysis and by changes in mechanical or thermomechanical behavior of the blends. Morphology studies were carried out. As a result, the tensile strength, tensile modulus, elongation at break, and tear strength of the final product were improved by about 15, 20, 160, and 50%, respectively, compared with the unfunctionalized blend. The hardness of the material remained unchanged in the compatibilization.

C−H Activation for the Construction of C−B Bonds

“…The ability to prepare polyolefins containing varying degrees of polar functional groups would expand the potential applications of materials derived from olefins. The incorporation of polar functionality is predicted to improve adhesion to metal and glass surfaces and permeability to gases among other properties. − Thus, a major goal for the synthesis of polyolefins has been the development of methods to generate materials containing functional groups, such as alcohols, amines, and carbonyl groups. One approach to the synthesis of such materials is the selective C−H bond functionalization of polyolefins.…”

Catalytic Hydroxylation of Polypropylenes

“…Currently, polyolefins constitute nearly 60% of all polymers produced . Although prepared on an enormous scale, the application of these polymeric hydrocarbons is limited by their low surface energies and poor adhesion with more polar materials, metals, and glass. ,− The effective preparation of polypropylene blends with polar macromolecules often requires the addition of polyolefin block or graft copolymers to prevent macrophase separation. − Therefore, the synthesis of polyolefins, particularly polypropylene, with polar side chains has been actively pursued. − …”

Peroxide Grafting of Powdered Polypropylene by Butyl Acrylate

“…Our selection of butyl acrylate was based on the possible combination of thermoplastic properties of polypropylene with elastomer properties of the polymerized grafting monomer similarly as it had been done elsewhere [1].…”