Poly(ethyleneterephthalate) (PET) degradation during the Zn catalysed transesterification with dibutyl maleate functionalized polyolefins

The chemical reactions occurring during the melt blending between a dibutyl maleate functionalized polyolefin (POF) and poly(ethylene terephthalate) (PET) in the presence of Zn(OOCCH3)2$2H2O were studied as a function of blending conditions, such as the preliminary drying of PET, the presence of a nitrogen flow during blending and the time of blending. The selective extraction of POF/PET 30/70 by weight blends to remove unreacted PET and the determination of its molecular weight by viscosimetric measurements allowed to evaluate both the grafting points’ number and the molecular weight of PET. In this way the impact of degradation of PET onto its grafting by transesterification onto POF was investigated. The examined blending conditions were shown to affect both PET degradation and POFePET copolymer formation. In order to correlate data about macromolecular and morphological structure with the final properties of the blends, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and tensile tests were also carried out

Photochemical stability of partially fluorinated acrylic protective coatings. IV. Copolymers of 2,2,2-trifluoroethyl methacrylate and methyl alfa-trifluoromethyl acrylate with vinyl ethers

The photochemical stability of copolymers of 2,2,2-trifluoroethyl methacrylate with butyl vinyl ether (TFEMA/BVE) and of methyl alpha-trifluoromethyl acrylate with 2-ethylhexyl vinyl ether, has been investigated under artificial solar light irradiation. In both copolymers, as well as in a reference ethyl methacrylate/BVE copolymer, the photoageing behaviour is controlled by the reactivity of the corresponding ether component. The degradation occurs mainly in the tertiary positions of the ether units, followed either by formation of gamma-lactones or by chain scissions. Only in the case of TFEMA/BVE does the fluorinated methyl of the side chain have an influence on the degradation pathways, i.e. a clear inhibition of cyclization