PP/LDPE blends produced by reactive processing. I. Grafting efficiency and rheological and high‐elastic properties of [PP/LDPE]‐g‐IA melts

Abstract

Itaconic acid (IA) was grafted onto polypropylene/low-density polyethylene (PP/LDPE) blends. The ratio of polymeric components was varied from 100 : 0 to 0 : 100. The effect of the variation in the ratios of the components on grafting efficiency and concomitant side processes was studied. Grafting of IA (1 wt %) was initiated by 2,5-dimethyl-2,5-di(tert-butyl peroxy)-hexane (0.3 wt %) and was carried out in an extruder reactor equipped with a dynamic mixer. An increase in the PP content of the blend led to a lower yield of the grafted product. With low concentrations of LDPE in the blend (up to 25 wt %), grafting efficiency was observed to increase, and this increase was greater in comparison with the additive rule. Between 25 and 99 wt % of LDPE in the blend, grafting efficiency rose monotonically with LDPE concentration. At or below an LDPE content of 25 wt %, the melt flow index (MFI) of [PP/LDPE]-g-IA would increase unlike with PP-g-IA systems. But a small quantity of PP (below 25 wt %) in the [PP/LDPE]-g-IA blends would result in a decreased MFI unlike with LDPE-g-IA. The dependence of swell index and melt strength on the ratio of polymeric components in [PP/LDPE]-g-IA blends also was investigated.

Compatibilizing effects of polypropylene-g-itaconic acid on the polypropylene composites

“…The PP macroradical was formed by a coupling Because of inductive effect, the tertiary radical is more stable than secondary and primary ones [15]. Table 1 summarizes PP grafted with IA (PP-g-IA) with different graft ratios of IA using 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane as an initiator.…”

Functionalization of LDPE and mLLDPE via grafting trans-ethylene-1,2-dicarboxylic acid by reactive extrusion

“…Values of σ m and B were found following the procedure described elsewhere [8]; the capillary diameter was 1.45 mm; length = 2 mm. Stress-strain (mechanical) properties of the materials were determined on samples injection moulded at 170°C.…”

“…On the other hand, technological equipment, particularly extrusion compounding reactors, has been updated continually, which should be taken into consideration in choosing optimal technological parameters for functionalization. Besides, the necessity of solving applied problems requires that basic research be done into functionalization of various olefin copolymers [1][2][3][4][5][6][7], polyethylene (PE) and polypropylene (PP) blends [8,9] as well as blends of polyolefins (PO) with copolymers of ethylene and higher olefins [10,11], copolymers of ethylene and vinyl acetate [12], linear polyethylene [13] and others. It should be noted that most studies of fundamental nature have been concerned with functionalization of PE and PP of conventional grades.…”

Functionalization of polyolefin melts containing carbon nanotubes and the properties of their blends with polyamide 6

“…The elasticity properties of the melts were estimated from their strengths (σ m ) and swell coefficients (B m ) [15]. To study the σ m and B m , a device was used based on the laboratory version of a piston-type molding machine whose nozzle had a capillary tube with a diameter of 1.45 mm and a length of 2 mm.…”