Maleated LDPE

PP/EVAc with maleated-LDPE melt strength and rigidity Idemitsu Petrochem., 1983... 

Polypropylene, 100 parts PP, blended with 8-25 parts of amorphous ethylene-propylene copolymer, EPR, and 2-10 parts crystalline EPR showed improved impact strength. In the Idemitsu patent, PP was blended with maleated LDPE, EVAc, and inorganic filler, to give blends with good melt strength and rigidity... 

This and LDPE were immiscible [103 105], forming thermoplastic elastomers with two continuous phases or IPNs. These were improved by adding compatibilizers such as epoxidized NR-I-maleated LDPE or sulfonated ethylene propylene-diene rubber (EPDM)-b maleated LDPE. These increased tensile strength, elongation, and adhesive peel strength. 

In our investigations of the PA6/maleated LDPE (0.5% MA) blend system [42], we found that for a standard PA6 with balanced end groups and a molecular weight (Mn) of 25,000, the brittle to ductile transition in the room temperature notched Izod impact, occurred... 

Figure 8.20 Effect of blending maleated LDPE (0.5% MA) on the notched Izod impact strength of PA6/ LDPE blends at room temperature [42]. (PA6 of = 24,000 [NH2] = [COOH] = 40 peq/g)...

Figure 8.22 Morphology of PA6/maleated LDPE (0.5% MA) blends [42]. (TEM, Phosphotungstic acid stain Top PA6/m-LDPE (60/40) blend Bottom PA6/m-LDPE (40/60) blend Note the phase inversion in...

ABA ABS ABS-PC ABS-PVC ACM ACS AES AMMA AN APET APP ASA BR BS CA CAB CAP CN CP CPE CPET CPP CPVC CR CTA DAM DAP DMT ECTFE EEA EMA EMAA EMAC EMPP EnBA EP EPM ESI EVA(C) EVOH FEP HDI HDPE HIPS HMDI IPI LDPE LLDPE MBS Acrylonitrile-butadiene-acrylate Acrylonitrile-butadiene-styrene copolymer Acrylonitrile-butadiene-styrene-polycarbonate alloy Acrylonitrile-butadiene-styrene-poly(vinyl chloride) alloy Acrylic acid ester rubber Acrylonitrile-chlorinated pe-styrene Acrylonitrile-ethylene-propylene-styrene Acrylonitrile-methyl methacrylate Acrylonitrile Amorphous polyethylene terephthalate Atactic polypropylene Acrylic-styrene-acrylonitrile Butadiene rubber Butadiene styrene rubber Cellulose acetate Cellulose acetate-butyrate Cellulose acetate-propionate Cellulose nitrate Cellulose propionate Chlorinated polyethylene Crystalline polyethylene terephthalate Cast polypropylene Chlorinated polyvinyl chloride Chloroprene rubber Cellulose triacetate Diallyl maleate Diallyl phthalate Terephthalic acid, dimethyl ester Ethylene-chlorotrifluoroethylene copolymer Ethylene-ethyl acrylate Ethylene-methyl acrylate Ethylene methacrylic acid Ethylene-methyl acrylate copolymer Elastomer modified polypropylene Ethylene normal butyl acrylate Epoxy resin, also ethylene-propylene Ethylene-propylene rubber Ethylene-styrene copolymers Polyethylene-vinyl acetate Polyethylene-vinyl alcohol copolymers Fluorinated ethylene-propylene copolymers Hexamethylene diisocyanate High-density polyethylene High-impact polystyrene Diisocyanato dicyclohexylmethane Isophorone diisocyanate Low-density polyethylene Linear low-density polyethylene Methacrylate-butadiene-styrene... 

A maleated ester of low density polyethylene, prepared by the reaction of LDPE and dibutyl maleate in solution, was blended with TPS by reactive extrusion. Mechanical properties of the blends were similar to those of the LDPE due to the compatibilization of these dissimilar components [75]. 

LDPE was functionalised in the bulk through dicumyl peroxide-initiated grafting of dibutyl maleate and vinyltrimethoxysilane in the temperature range from 140 to 200 °C (327). 

PA6/LDPE blends compatibilized using maleated hydrolyzed ethylene-vinyl acetate copolymer (EVALM) Crystallinity was studied using DSC EVALM affected the degree of crystallinity and Tg of PA6 phase Luo et al. 2001... 

Numerous articles and patents were published on diverse methods of LLDPE blending with other POs and elastomers, e.g., /m-LLDPE, LDPE variety of ethylene copolymers, thermoplastic elastomers, TPO, EPDM, EPR, EVAc, maleated polypropylene, and PP-MA (Haas and Raviola 1982 Hughes 1982 Cowan 1983 Jager et al. 1983 Turtle 1983 Fukui et al. 1983 Haas 1983 Hert 1983). 

The first LDPE/HDPE blends were patented by du Pont de Nemours before Z-N polymers became available (Roedel 1961). The blend comprised an experimental HOPE (p = 0.939-1.096 g mL Tm 120 °C) obtained by polymerizing C2 in its own medium at T 0 °C and P 31 MPa, using, e.g., a hydroxy-cyclohexyl-L-hydroperoxide catalyzed by ferrous chloride tetrahydrate. The blend showed 50 % moisture permeabDity of that by LDPE. In 1958 Phillips Petroleum patented PE/PE blends, either cross-linked in electron accelerator or not (Canterino and Martinovich 1963 Nelson 1964). Mitsubishi disclosed PO blends comprising vinyl-trimethoxysUane-grafted polyolefin (PP, LDPE, EPR, or EVAc) and ethylene-acryloyloxy tetramethylpiperidine copolymer. These water-cross-linkable resins were used for the manufacture of weather-resistant cross-linked PO pipes in outdoor applications (Ohnishi and Fukuda 1993). Thermally reversible cross-links (based on ionic interaction between maleated- and glycidyl methacrylate-grafted polyolefins) were also proposed (Okada 1994 Okada and Masuyama 1994). 

In 1979, the UNIPOL process for gas-phase production of LLDPE was introduced by the Union Carbide Corp. Since the new resins were difficult to process on the lines designed for LDPE, by 1982 several patents were issued for improvement of LLDPE processability by blending it with other polyolefins, viz., LDPE, PP, and olefinic rubbers. Ethylene copolymers, rubbers, EPDM, EVAc, maleated polypropylene, EPR, etc., have also been used (Cowan 1983 Turtle 1983 Fukui et al. 1983 Haas 1983 Hert 1983). Thus, blends LLDPE/LDPE were found miscible at low LDPE contents, then immiscible at high LDPE. Addition of HDPE as cosolvent resulted in miscible tertiary blends (Lee and Denn 2000). 

Low-density polyethylene, 5-120 parts LDPE, was blended with chlorosulfonated polyethylene, 100 parts CSR, with or without curing agent (tribasic lead maleate). The blends found were used as smooth, non-tacky, tough films or coatings for natural or synthetic rubbers ... 

The LDPE Grade 464 was fed to a Mixer-600 attached to Haake Record meter at temperature = 150°C and RPM = 64. After 5 min, MA was fed portion wise and the peroxide was added drop wise. The modified PE was characterized by FTIR and evaluated via the degree of maleation (%) according to (Ghaemy et al., 2003 Moayad etal., 2008). 

SEM photomicrographs of the 70/30 PET/LDPE+diethyl maleate grafted ultra-low-density polyethylene (ULDPE-g-DEM) blends obtained with a mixing time of 20 min. (A) and (B) no copolymer, sample cut parallel to flow direction (C) no copolymer, sample cut perpendicular to flow direction. (From M. B. Coltelli, Catalysed Reactive Compatibilization of Polyolefin and Poly(ethyIene terephthalate) Blends Reactions Mechanisms and Phase Morphology Development, Ph.D. thesis. University of Pisa, Italy, 2005.)... 

PE PET PE-g-maleate PE = LDPE/LLDPE blend maleate = diatkyl maleate transesterification catalyst added to improve grafting 131... 

---