Morphology control of polyester-polyolefin blends by transesterification during processing operations in the presence of dibutyltin oxide

Abstract

PE and PBT are known to be incompatible polymers. A grafted copolymer PBT-EVA has been generated as a compatibilizer in situ during the processing operation by redistributive transesterification between PBT and EVA in the presence of dibutyl tin oxide (DBTO). This copolymer has been isolated by selective extractions from PBT/EVA/DBTO (49.5/49.5/1% in weight) blend after processing in the melt. It has been evidenced by a 1 H-NMR study. This copolymer presents all the resonances of PBT and EVA sequences and some others that have been assigned specificaly to grafting. To achieve these assignments, a model compound obtained by transesterification of EVA with methyl benzoate has been used. When the melt conditions enable synthesis of the grafted copolymer PBT-EVA in situ during processing operations, important changes in the morphology of PE/PBT/EVA/DBTO blends are observed. SEM analysis shows a decrease of PBT particle size and a good adhesion between the PBT and PE phase.

Chemical Structure and Microstructure of Poly(alkylene terephthalate)s, their Copolyesters, and their Blends as Studied by NMR

“…[ 58,[275][276][277] This literature shows that NMR is the preferred spectroscopic method to realize the characterization of the chemical structure and microstructure of the copolymers generated by mutual interchange reactions of PBT with aromatic polyesters such PET, [ 135,148,278 ] and PTT, [ 279 ] aliphatic polyesters such as poly(butylene succinate) (PBS), [ 280 ] polycarbonate (PC), [ 190,275,281,282 ] and polyarylates of bisphenol-A (PAR), [283][284][285][286][287][288] polyamides, [289][290][291][292] polyurethanes, [ 293 ] or modifi ed polyolefi ns. [ 294,295 ] Blends of PBT with polyarylates have been developed due to their excellent processing, high thermal defl ection temperature, high impact toughness, and weatherability. [ 276 ] Although these blends are readily miscible, [ 296 ] it is known that crystallization of PBT induces phase separation.…”

Complex processing–morphology interrelationships during the reactive compatibilization of blends of poly(butylene terephthalate) with epoxide‐ containing rubber

“…Such blends have attracted much attention over the last decade. [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] To obtain improved impact resistance, a good dispersion of the rubber is required. Blend compatibilization is, therefore, indispensable.…”

“…Reactive compatibilization of polyester/polyolefin blends can be achieved by several approaches based on the reactivity of the carboxyl and the hydroxyl end groups of the polyesters. In this context, acrylatebased copolymers, 2-4 maleic anhydride-containing elastomers, [5][6][7] epoxidized polyolefins, 8 -18 the ethylene-vinyl acetate copolymer, 19 an oxazoline-modified polymer, 20 and core-shell impact modifiers 21 have already been used as toughening agents. In most cases, epoxide-containing rubbers appeared to be the most effective to toughen both PBT and PET.…”

Improved thermostability and interfacial matching of nanoclay filler and ethylene vinyl alcohol matrix by silane‐modification

“…[14][15][16][17] On the other hand, surface modification of polymers is often accomplished by the grafting of polymers using common polymerization reactions. [18][19][20] Silanization of either the polymer or the nanoclay filler has also been described in the literature for this purpose. [21][22][23][24] However, to the best of our knowledge, the simultaneous use of silane coupling agents for the surface treatment of both polymers and nanoclays have so far not yet been described in the literature.…”