Mechanical, thermal and morphological characterization of recycled LDPE/corn starch blends (original) (raw)
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Processing and characterization of LDPE/starch products
Journal of Applied Polymer Science, 2001
Low-density polyethylene/plastisized starch blends varying in starch content were processed by conventional extrusion, injection-molding, and film-blowing techniques. Polyethylene-g-maleic anhydride (PE-g-MA) was used as a compatibilizer. X-ray diffraction was used to investigate starch destructurization during extrusion and on subsequent processing. The effect of starch content on the blends was evaluated by mechanical property measurement and scanning electron microscopy. Starch, except for being a biodegradable material, can also act as a reinforcing agent. The reinforcing effect of starch was only realized in injection-molded materials. Processing-structureproperty relationships could explain this behavior. The present study also brought out the effect that the degree of molecular orientation existing in a polymeric matrix may have on the coupling performance of an adhesion promoter.
Enhancing degradability of plastic waste by dispersing starch into low density polyethylene matrix
Process Safety and Environmental Protection, 2018
A biodegradable polymer film by dispersing starch into LDPE matrix was produced Film homogeneity was studied by SEM and FTIR to justify starch dispersion in LDPE matrix Biodegradability was tested under soil burial condition varying starch content. Chemical resistance was assessed by immersing it in 10% NaOH and 10% HCl solution. Mechanical properties of the film was tested and compared with virgin LDPE.
A high-content starch/low-density polyethylene (LDPE) blend with acceptable biodegradation and mechanical properties was produced by adjusting the compatibility of the blend system and processing plasticisation through the compatibiliser and different processing method. Two kinds of compatibilisers, maleic anhydride grafted LDPE after plasma treatment (MA-g-PLDPE) and acrylic acid grafted LDPE after plasma treatment (AAc-g-PLDPE), were synthesized and used in this work. The grafting degree (GD) of MA-g-PLDPE was 1.90 ! 10 ÿ4 mol/g. The GD of AAc-g-PLDPE was 2.5 ! 10 ÿ4 mol/g. MA-g-PLDPE gave more compatibility than AAc-g-PLDPE by the anhydride groups. The plasticisation effect by the oligomer resulted from a different process by mixing the MA-g-PLDPE and/or maleic anhydride (MA) with glycerol before compounding was investigated. As the MA and compatibiliser/LDPE premixed with GA for 30 min, the LDPE particle size of blends decreased with increasing compatibiliser content. If the free MA was not added, the PE blends show irregular shapes. The weight loss of all samples achieved above 65 wt% after two weeks of biodegradation. The weight losses of blends that contain free MA were higher than those without free MA. Finally, the structure of blends after soil burial was observed by SEM.
Physical and thermal mechanical properties of corn starch/LDPE composites
Journal of Applied Polymer Science, 2013
The potential of biodegradable polymers has long been recognized. In this work, composites of low density polyethylene (LDPE) and low density polyethylene/thermoplastic starch (LDPE/TPS) at different ratios of TPS (40%-60% w/w) were prepared in internal mixer. Polyethylene-grafted maleic anhydride (PE-g-MA) at 3 wt % was used as coupling agent. Chemical reactions between functional groups of composite components were studied and confirmed by Fourier transforms infrared (FTIR) spectroscopy. The morphology of film surfaces was studied using scanning electron microscopy. The physical, mechanical, and dynamic-mechanical thermal analyses of LDPE/TPS composites were evaluated. The FTIR results showed transmission peak at 1642 cm À1 , which is the result of chemical reaction between the hydroxyl groups of starch and anhydride groups of coupling agent. This verifies the presence of the carboxylate group due to the formation of ester bonding. The results showed that the water absorption and density of composite films increased by increasing the starch content in LDPE/TPS composites. The tensile strength and elongation at break decreased by increasing the starch level in the composites, but the young's modulus increased. The morphological studies showed that the biodegradability of composites increased by increasing the starch content and the results was confirmed by weight loss in buring the samples in wet soil during time intervals. The dynamic mechanical thermal analyzer thermograms showed that there are two relaxation temperature peaks. The amplitude of peaks increased by increasing the starch content from 40 to 60% probably due to increasing amorphous phase of composite. The starch was uniformly distributed throughout the LDPE polymer matrix and compatible and biodegradable composites were formed. V
Evaluation of photodegradation in LDPE/modified starch blends
Polimeros-ciencia E Tecnologia, 2009
Low density polyethylene (LDPE), EB-853, with a flow index of 2.7 g/10 minutes (190° C/2.160 kg), was supplied by BRASKEM. The starch used was Foxhead ® 5901, amphiprotic type, made up of 27% amylose and 73% amylopectin, supplied by Corn Products Brazil. Blend preparation The LDPE/modified starch blends, with a composition of 80/20 w/w, were obtained by melt mixing in the mixture chamber of a HAAKE rheometer, under the following conditions: 50 g, temperature at 140 °C, maximum torque 50 Nm, rotor rate 50 rpm, and mixing time 10 minutes. After blend was triturated in a grinding rotor axis, and its films were obtained in an hydraulic press, with a thickness of 0.175 + 0.025 mm, in the following conditions: force 8 ton, time compressed for 1 minute, plates temperatures in a 140 °C and mold with 400 cm 2[15] .