A comparative study on the efficiencies of polyethylene compatibilizers by using theoretical methods

Functionalization of polyethylene chains by grafting of polar groups onto backbones is the most versatile way for preparing polyethylene based compatibilizers (PECs). In this work, a series of theoretical studies were performed to analyze the structure, adhesion and mixing behaviors of PECs. The effect of grafting different polar groups such as acrylic acid (AA), glycidyl methacrylate (GMA), maleic anhydride (MAH) and itaconic acid (IA) on the structure and cohesive properties of polyethylene chains were studied by Molecular Dynamics simulations. The mixing behavior of grafted polyethylenes with some commodity polymers such as polyetylene teraphthalate (PET), polyamide 6 (Nylon6), polyvinyl acetate (PVA) and polylactide (PLA) as well as with starch (ST) and starch acetate (STac) were investigated quantitatively by determining accurate interaction parameters using the modified Flory-Huggins Theory. We showed that the polar groups are the most reactive sites and they bind the chemically incompatible polymers by enabling the stronger interactions at the interfacial region

Non-isothermal crystallization of semi-crystalline polymers : the influence of cooling rate and pressure

During industrial processing, polymer melts are exposed to local high cooling rates, strong deformation rates and high pressures. Nowadays, research in the field of semi-crystalline polymers still strives towards an accurate prediction of the evolution and final appearance of the crystalline morphology in polymer products. After all, the amount, number, phase and orientation of the crystallites act in a combined way and control the final optical and mechanical properties. This chapter discusses recent experimental and model developments concerning the influence of industrially relevant cooling rates and pressures on the non-isothermal crystallization of both an isotactic polypropylene and a linear low-density polyethylene grade. The influence of flow gradients is discussed in Chapter (Roozemond et al., Adv Polym Sci, 2016