scholarly journals Polyethylene glycol grafted with carboxylated graphene oxide as a novel interface modifier for polylactic acid/graphene nanocomposites

2020 ◽  
Vol 7 (7) ◽  
pp. 192154
Author(s):  
Mingjun Niu ◽  
Hao Wang ◽  
Jing Li ◽  
Hongyan Chen ◽  
Lin Li ◽  
...  

Strength and toughness are both of great importance for the application of polylactic acid (PLA). Unfortunately, these two properties are often contradictory. In this work, an effective and practical strategy is proposed by using carboxylated graphene oxide (GC) grafted with polyethylene glycol (PEG), i.e. GC-g-PEG. The synthesis procedure of GC-g-PEG is firstly optimized. Then, a series of PLA nanocomposites were prepared by the melt blending method via masterbatch. In comparison to that achieved over pure PLA, these nanocomposites are of higher crystallinity, thermal stability and mechanical strength. This is mainly attributed to well-tailored interface and good dispersion. Especially, while retaining the tensile strength of the original PLA, the elongation at break increases by seven times by adding 0.3 wt% GC-g-PEG.

2016 ◽  
Vol 846 ◽  
pp. 429-433 ◽  
Author(s):  
Buong Woei Chieng ◽  
Ibrahim Nor Azowa ◽  
Yoon Yee Then ◽  
Yuet Ying Loo

Poly(lactic acid) (PLA)-based nanocomposites filled with graphene nanoplatelets (xGnP) and containing epoxidized palm oil (EPO) as plasticizer were prepared by melt blending method. PLA was first plasticized by EPO to improve its flexibility and thereby overcome its problem of brittleness. Then, xGnP was incoporated into plasticized PLA to enhance its mechanical properteis. Plasticized and naonofilled PLA nanocomposites (PLA/EPO/xGnP) showed improvement in the elongation at break by 61% compared with plasticized PLA (PLA/EPO). The use of EPO and xGnP increases the mobility of the polymeric chains, thereby improving the flexibility and plastic deformation of PLA. The nanocomposites also resulted in an increase of up to 26.5% in the tensile strength compared with PLA/EPO blend. PLA/EPO reinforced with xGnP shows that increasing the xGnP content triggers a substantial increase in thermal stability. The TEM image of PLA/EPO/xGnP shows that the xGnP was uniformly dispersed in the PLA matrix and no obvious aggregation is observed.


2014 ◽  
Vol 970 ◽  
pp. 312-316
Author(s):  
Sujaree Tachaphiboonsap ◽  
Kasama Jarukumjorn

Thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend and thermoplastic starch (TPS)/poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend were prepared by melt blending method. PLA grafted with maleic anhydride (PLA-g-MA) was used as a compatibilizer to improve the compatibility of the blends. As TPS was incorporated into PLA, elongation at break was increased while tensile strength, tensile modulus, and impact strength were decreased. Tensile properties and impact properties of TPS/PLA blend were improved with adding PLA-g-MA indicating the enhancement of interfacial adhesion between PLA and TPS. With increasing PBAT content, elongation at break and impact strength of TPS/PLA blends were improved. The addition of TPS decreased glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm) of PLA. Tgand Tcof TPS/PLA blend were decreased by incorporating PLA-g-MA. However, the presence of PBAT reduced Tcof TPS/PLA blend. Thermal properties of TPS/PLA/PBAT blends did not change with increasing PBAT content. SEM micrographs revealed that the compatibilized TPS/PLA blends exhibited finer morphology when compared to the uncompatibilized TPS/PLA blend.


2013 ◽  
Vol 785-786 ◽  
pp. 123-126
Author(s):  
Ying Ye ◽  
Kun Yan Wang ◽  
Ge Chang ◽  
Qian Ying Jiang

Polypropylene/organoclay modified by dodecanol phase change material were prepared by melt blending method. The thermal stability and crystallization behavior was studied by thermogravimetry (TG), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). TG results indicated the window of processing of PP could be improved by adding small amount organoclay modified by dodecanol to the blend. DSC showed the organoclay modified by dodecanol affected the crystallization behavior of PP as heterogeneous nucleation agent. XRD results show that the organoclay modified by dodecanol does not change the crystal structure in the blends but only decrease the intensity of the diffraction peak.


Polymers ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1283 ◽  
Author(s):  
Miao Miao ◽  
Chunyan Wei ◽  
Ying Wang ◽  
Yongfang Qian

To improve the interfacial bonding and thermal stability of graphene oxide (GO)/polypropylene (PP) composite fibers, a composite fiber with PP as the matrix, GO as reinforcement and maleic anhydride-grafted PP (PP-g-MAH) as a compatibilizer was prepared by a simple and efficient melt-blending method. The GO content was 0.0–5.0 wt %. According to the Fourier Transform Infrared (FT-IR) spectroscopy results, the interfacial bonding in the PP/MAH/GO composite fibers was improved. The Dynamic Mechanical Analysis (DMA) results show that the addition of GO resulted in better interfacial adhesion and higher storage modulus (E′). The loss modulus (E′′) of the PP/MAH/GO-x composite fibers increased with increasing amount of added GO, whereas the loss factor (tan δ) decreased. GO and PP-g-MAH were analyzed by Thermogravimetric Analysis (TGA). The thermal stability of the composite fibers was improved compared to PP. Differential Scanning Calorimetry (DSC) analysis showed that the addition of PP-g-MAH to the composite fiber improved the interfacial bonding of GO in the PP matrix. Thus, compatibility between the two components was obtained. Based on the Scanning Electron Microscopy (SEM) results, the PP fibers exhibited relative orientation due to the strong crystalline morphology. The rough section, PP/GO blend fiber exhibits a very clear phase separation morphology due to the incompatibility between the two and the compatibility of GO and PP in PP/MAH/GO-3 composite fiber is improved, resulting in the interface between the two has improved.


2014 ◽  
Vol 34 (9) ◽  
pp. 813-821 ◽  
Author(s):  
Gaurav Madhu ◽  
Haripada Bhunia ◽  
Pramod K. Bajpai ◽  
Veena Chaudhary

Abstract Polyblend films were prepared from high-density polyethylene (HDPE) and poly(l-lactic acid) (PLLA) up to 20% PLLA by the melt blending method in an extrusion mixer with post-extrusion blown film attachment. The 80/20 (HDPE/PLLA) blend was compatibilized with maleic anhydride grafted polyethylene (PE-g-MA) in varying ratios [up to 8 parts per hundred of resin (phr)]. Tensile properties of the films were evaluated to obtain optimized composition for packaging applications of both non-compatibilized and compatibilized blends. The compositions HDPE80 (80% HDPE and 20% PLLA) and HD80C4 (80% HDPE, 20% PLLA and 4 phr compatibilizer) were found to be optimum for packaging applications. However, better tensile strength (at yield) and elongation (at break) of 80/20 (HDPE/PLLA) blend were noticed in the presence of PE-g-MA. Further, thermal properties and morphologies of these blends were evaluated. Differential scanning calorimetry (DSC) study revealed that blending does not much affect the crystalline melting point of HDPE and PLLA, but heat of fusion of 80/20 (HDPE/PLLA) blend was decreased as compared to that of neat HDPE. Spectroscopy studies showed evidence of the introduction of some new groups in the blends and gaining compatibility in the presence of PE-g-MA. The compatibilizer influenced the morphology of the blends, as apparent from scanning electron microscopy (SEM) and supported by Fourier transform infrared (FTIR).


2011 ◽  
Vol 117-119 ◽  
pp. 1402-1405
Author(s):  
Hao Wu ◽  
You Ming Cao

PVC/BaSO4 composites were prepared by melt blending method. The mechanical properties, microstructure and thermal stability of the composites were investigated. The results indicated that BaSO4 decreased the tensile yield stress and improved the elongation at break of PVC composites. Ductile fracture characteristics such were observed in the tensile fracture surface of PVC/BaSO4 composites. The toughening mechanism was cavitations toughening mechanism and shear zone toughening mechanism. The reaction of dehydrochlorination was limited by the addition of BaSO4.


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