0000000000369877
AUTHOR
Fp La Mantia
Reprocessing of polyethyleneterephthalate and characterisation of monopolymer blends of virgin and recycled polymers
Recycling of polyethyleneterephthalate (PET from bottles is considered by changing both reprocessing machines and the effect of humidity. The rheological and mechanical properties of this recycled material remain very close to that of the virgin material provided that a careful drying is carried out before any melt operation. The reprocessing has been carried out mainly in view of the use of this secondary material in blends with virgin PET-monopolymer or homopolymer blends. Indeed, this use is a common industrial practice to reuse plastic scraps. Most monopolymer blends show properties between those of the two components but in some cases lower than those expected on the basis of an additi…
Effects of Organoclay on Morphology and Properties of Nanocomposites Based on LDPE/PA6 Blends without and with SEBS-g-MA
LDPE/PA-6 blends (75/25 wt/wt) were added with SEBS-g-MA (S) and/or an organoclay (20A) using different compounding sequences and the morphology and the properties of the blends or composites were investigated. An XRD study of the nanocomposites with pure polymers showed that 20A is intercalated by LDPE or PA-6 chains, whereas it is exfoliated by S if the clay concentration does not exceed 10 wt%. The SEM investigation showed that both S and 20A behave as efficient emulsifying agents for the LDPE/PA-6 blends. However, their effect on the mechanical properties was found to be opposite: S enhanced toughness but lowered the stiffness, whereas 20A improved the elastic modulus but impaired the i…
On the mechanism of compatibilization of polyolefin/liquid crystalline polymer blends with graft copolymers
The compatibilization mechanism of some compatibilizers for blends of polyolefins with a liquid crystalline polymer (LCP) was studied. Polyethylene (PE) and polypropylene (PP) were blended with a semirigid LCP (SBH) in a batch mixer, either with and without compatibilizers. The latter were two commercially available samples of functionalized polyolefins, that is, a PE-g-MA (HDM) and a PP-g-AA (Polybond 1001) copolymer and some purposely synthesized PE-g-LCP and PP-g-LCP copolymers. Microtomed films of the binary and the ternary blends were annealed at 240 degrees C on the hot stage of a polarizing microscope and the changes undergone by their morphology were recorded as a function of time. …
Processing and characterization of blends of fluoroelastomers with semirigid liquid crystal polymers
Fluoroelastomers (FEs) usually have working temperatures above 150 degrees C and a great resistance to aggressive agents such as oils, fuels, aliphatic and aromatic solvents, steam, moderate acid, and basic environments. Liquid crystal polymers (LCPs) can be effective processing aids and reinforcing agents for elastomers. These characteristics are very attractive to lower melt viscosity and to stiffen and strengthen the final product through a simple blending. Among the LCPs, the semirigid LCPs seem the most appealing for blending with flexible thermoplastics (FTs) because their processing temperatures can be arranged to be in the same processing temperature range of FTs and because the pre…