HIGH-STRENGTH BIMODAL POLYETHYLENE COMPOSITIONS Russian patent published in 2010 - IPC C08L23/04 C08F10/02 F16L9/12 

FIELD: chemistry.

SUBSTANCE: invention relates to high-strength bimodal polyethylene compositions which are meant for preparing compositions for pipes, particularly high-strength compositions for pipes. The composition has density equal to or greater than 0.940 g/cm³, overall polydispersity index equal to or greater than 25 and contains a high-molecular polyethylene component and a low-molecular polyethylene component. The ratio of weight-average molecular weight of the high-molecular component to the weight-average molecular weight of the low-molecular component of the composition is equal to or greater than 30. The weight-average molecular weight of the low-molecular polyethylene component ranges from 5000 to 30000. The composition is classified as PE 100 material, has proper balance of properties such as strength and hardness, as well as good processing properties. A pipe made from the composition which has undergone internal strength tests has extrapolated stress equal to or greater than 10 MPa when the internal strength curve of the pipe is extrapolated to 50 or 100 years in accordance with ISO 9080:2003(E).

EFFECT: increased strength of products.

15 cl, 6 tbl, 10 ex