Engineering mechanics of polymeric materials : theories properties and applications 1. Interaction of physico mechanical and physico chemical properties of polymer materials G.G. Aliyev and F.B. Nagiyev 2. Stress strain state of a sandwich thick walled pipe with regard to change of physico chemical properties of the material G.G. Aliyev and F.B. Nagiyev 3. Stress deformation and strength of sandwich reinforced thick walled pipes with regard to change of physico chemical properties of binder G.G. Aliyev and F.B. Nagiyev