Effects of Maleated Natural Rubber on Mechanical Properties of Polylactic Acid/Natural Rubber Blends

2015 ◽  
Vol 819 ◽  
pp. 284-289 ◽  
Author(s):  
N.N.B. Mohammad ◽  
A. Arsad ◽  
A.R. Rahmat ◽  
N.S. Abdullah Sani

Brittle Polylactic acid (PLA) was toughened by introducing 5-20 wt. % of Natural Rubber (NR) through melt blending in a twin screw extruder. The results of tensile strength and Young’s modulus of PLA/NR blends were dramatically decreased. Maleic anhydride grafted natural rubber (NR-g-MA) was prepared and used to enhance the blends performance. The preparation of NR-g-MA was carried out using internal mixer by free radical melt grafting reaction followed by Fourier transform infrared spectroscopy (FTIR) to analyze the incorporation of MA on the NR. The compatibilization effect on the mechanical properties of PLA/NR blends was investigated with addition of 3 phr NR-g-MA. Comparison between PLA/NR/Compatibilizer and virgin PLA/NR blends significantly improved on the mechanical properties. FTIR result confirmed grafting reaction occurred between MA and NR.

2014 ◽  
Vol 554 ◽  
pp. 81-85 ◽  
Author(s):  
Nor Nisa Balqis Mohammad ◽  
Agus Arsad ◽  
Abdul Razak Rahmat ◽  
Mohammad Shukor Talib ◽  
Mohd Shaiful Zaidi Mat Desa

Derived from renewable resources, Poly (lactic) acid (PLA) exhibits good mechanical properties comparable with conventional polyolefins. However, major obstacle in PLA which may limit its application is due to brittleness. Thus, PLA requires toughening to overcome the weakness. In this study, PLA was blended with different ratio of natural rubber (0 to 20 wt.%) through melt blending in a twin screw extruder. The results of tensile strength and Young’s modulus of PLA/NR blends were decreased. In order to enhance the blend performance, PLA grafted maleic anhydride (PLA-g-MA) was used as compatibilizer. The preparation of PLA-g-MA was carried out using internal mixer by free radical melt grafting reaction followed by Fourier Transform Infrared Spectroscopy (FTIR) analysis to confirm the grafting reaction. To investigate the compatibilization effect on the mechanical properties of PLA/NR blends, PLA-g-MA was added to the blends at various compositions (1 – 10 phr). Mechanical properties increased markedly compared to the virgin PLA/NR blends and FTIR result confirmed grafting reaction occurred between MA and PLA.


2010 ◽  
Vol 123-125 ◽  
pp. 1167-1170 ◽  
Author(s):  
Punmanee Juntuek ◽  
Chaiwat Ruksakulpiwat ◽  
Pranee Chumsamrong ◽  
Yupaporn Ruksakulpiwat

Polylactic acid (PLA) and natural rubber (NR) were melt blended with vetiver grass fiber using an internal mixer. Heat treatment at the temperature of 180°C was done to obtain heat treated vetiver grass fiber. Glycidyl methacrylate grafted natural rubber (NR-g-GMA) was used as a compatibilizer of PLA/vetiver/NR composites. The injection molding and compression molding were used to prepare the specimens. Molecular weight determination of PLA before and after processing was done by Gel Permeable Chromatography (GPC).Comparisons between the mechanical properties of the composites prepared from injection molding and compression molding were made.


2002 ◽  
Vol 75 (4) ◽  
pp. 617-625 ◽  
Author(s):  
Jeong Seok Oh ◽  
A. I. Isayev

Abstract Compounding ground tire rubber (GRT) with commercial polyolefins such as polypropylene (PP) is a possible way of recycling GRT. These new blends can provide low cost materials. The present study describes new materials which are obtained by the ultrasonically treated PP/GRT blends. In order to improve the efficiency of the treatment process, a new ultrasonic reactor was built. In this reactor, two horns were placed in a slit die which is attached to a plastic extruder. PP/GRT blends mixed by using a twin screw extruder were passed through the reactor to devulcanize GRT. Then the blends were dynamically revulcanized using an internal mixer. Mechanical properties, rheology and morphology of the obtained blends were studied. Under optimal conditions of ultrasonic treatment, the mechanical properties of the blends were improved in comparison with our earlier experiments.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1510
Author(s):  
Marek Pöschl ◽  
Shibulal Gopi Sathi ◽  
Radek Stoček ◽  
Ondřej Kratina

The rheometer curing curves of neat natural rubber (NR) and neat chloroprene rubber (CR) with maleide F (MF) exhibit considerable crosslinking torque at 180 °C. This indicates that MF can crosslink both these rubbers via Alder-ene reactions. Based on this knowledge, MF has been introduced as a co-crosslinking agent for a 50/50 blend of NR and CR in conjunction with accelerated sulfur. The delta (Δ) torque obtained from the curing curves of a blend with the addition of 1 phr MF was around 62% higher than those without MF. As the content of MF increased to 3 phr, the Δ torque was further raised to 236%. Moreover, the mechanical properties, particularly the tensile strength of the blend with the addition of 1 phr MF in conjunction with the accelerated sulfur, was around 201% higher than the blend without MF. The overall tensile properties of the blends cured with MF were almost retained even after ageing the samples at 70 °C for 72 h. This significant improvement in the curing torque and the tensile properties of the blends indicates that MF can co-crosslink between NR and CR via the Diels–Alder reaction.


2014 ◽  
Vol 1025-1026 ◽  
pp. 580-584 ◽  
Author(s):  
Phrutsadee Sukpuang ◽  
Mantana Opaprakasit ◽  
Atitsa Petchsuk ◽  
Pakorn Opaprakasit

Glycolyzed polylactic acid (GPLA)-cured epoxidized natural rubber (ENR) is developed for use as a toughening agent for PLA resin. GPLA is obtained from chemical recycling of PLA resin by a glycolysis reaction. GPLA-cured ENR is then prepared by the crosslinking reaction of ENR with GPLA in an internal mixer. Chemical structures of the cured products are characterized by solvent fractionation and thermogravimetric analysis (TGA). The cured ENR products are blended with PLA resin, by varying the cured ENR contents from 5 to 15% wt. Mechanical properties of the blends, and their toughening mechanisms are examined. The cured ENR materials has higher efficiency in improving toughness of PLA resin, compared to uncured ENR, likely due to their rubbery network nature and higher compatibility with the PLA matrix. The incorporation of 5% wt. GPLA-cured ENR also improves elongation at break with no adverse effect on tensile strength and modulus of PLA.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Quang Nguyen Trong ◽  
Hung Dang Viet ◽  
Linh Nguyen Pham Duy ◽  
Chuong Bui ◽  
Duong Duc La

Selection of a suitable thermal aging process could render desirable mechanical properties of the rubbers or blended rubbers. In this work, the effect of the aging processes on the mechanical properties and activation energies of natural rubbers (NR) and NR/chloroprene rubbers (CR) blends with low CR contents (5–10%) was investigated. Three aging processes including heat aging (at 110°C for 22 hours), mechanical aging (under dynamic loading to 140% strain for 16000 cycles), and complex aging (heat and mechanical aging) were studied. The results revealed that the compatibility of CR in natural rubber matrix had a significant effect on the dynamic properties of the blended rubber and negligible effect on the static properties. The changes in activation energies of the blended rubber during aging processes were calculated using Arrhenius relation. The calculated changes (ΔUc, ΔUd, and ΔUT) in activation energies were consistent with the results of mechanical properties of the blended rubber. Interestingly, the change in activation energies using complex aging conditions (ΔUc) was mostly equal to the total changes in activation energies calculated separately from heat aging (ΔUT) and mechanical aging (ΔUd) conditions. This indicates that, in complex aging conditions, the heat and dynamic loading factors act independently on the properties of the blended rubber.


Sign in / Sign up

Export Citation Format

Share Document