Long-chain branched polypropylene obtained using an epoxy resin as crosslinking agent

JORGE A. GUAPACHA; ENRIQUE M. VALLÉS; LIDIA M. QUINZANI; MARCELO D. FAILLA

POLYMER BULLETIN

SPRINGER

Lugar: Berlin; Año: 2017

0170-0839

A reaction between a linear polypropylenefunctionalized with maleic anhydride (PPg)and epoxy resin (bisphenol A diglycidyl ether) was carried out on the moltenstate to generate long chain branches (LCB) in the molecular structure of thePPg. Concentrations of epoxy resin (ER) of up to 3.15wt%were employed to obtain different levels of branching. FTIR spectroscopyanalysis indicates that during the reaction, anhydride groups in PPgare consumed and new ester groups are formed. Thepresence of branches was verified using multiple-detection size-exclusionchromatography and rheology. The degree of long chain branching induced in PPgaugments with increasing concentration of ER. Furthermore, the materialsmodified with higher content of ER display gel-like behavior. The long chainbranched polymers also display thermo-rheological complexity. Thermalcharacterization studies show that LCBs have a nucleating effect duringcrystallization. This causes the augment of the crystallization activationenergy of PPg