Plasticized thermoplastic semicrystalline block copolymers

Abstract

Abstract Novel plasticized thermoplastic copolymers are described wherein said copolymer is selected from the group consisting of block copolymers having the general formulae, I. A-B-A II. A-B-A-B-A III. xB-(A-B)n-yA, and graft copolymers having the general formula WHEREIN M AND N ARE INTEGERS GREATER THAN 1; X AND Y AND 0 OR 1, AND Y IS 0 WHEN N IS 2; AND A and B are mutually incompatible thermoplastic polymer blocks, wherein the A block is a crystalline phase or semicrystalline phase having a crystalline content of at least 25 percent and the B block is a substantially non-crystalline plastic, and said plasticizer is selected from the group consisting of plasticizers having a solubility parameter within 1.2 of the solubility parameter of said B polymer block. Preferably the A polymer block has a crystalline melting point of at least 35*C. and a molecular weight of at least 5,000 while the B polymer block is preferably prepared from vinyl aromatics and has a molecular weight of at least 5,000 and a glass transition of at least 35*C. In general from 25 to 300 parts per hundred plasticizer is added to the copolymers described above to prepare the novel compositions claimed herein. In the most preferred embodiment the copolymers are: polyethylene-polystyrene-polyethylene, where the plasticizer is a non-volatile phthalate ester such as dibutyl phthalate or polyethylene-poly-t-butyl styrene-polyethylene where the plasticizer is an oil having a low aromatics content, for example, an oil of about 1-2 percent aromatic content, 10-13 percent paraffin content, and 82-88 percent naphthenic content.

Inventors

• 👤 H Makowski
• 👤 R Lundberg

Bibliographic Details