Mechanical properties of graphene and nano-diamond reinforced ultra high molecular weight polyethylene

Mechanical properties of graphene and nano-diamond reinforced ultra high molecular weight polyethylene

Materials Today: Proceedings xxx (xxxx) xxx Contents lists available at ScienceDirect Materials Today: Proceedings journal homepage: www.elsevier.co...

883KB Sizes 0 Downloads 11 Views

Materials Today: Proceedings xxx (xxxx) xxx

Contents lists available at ScienceDirect

Materials Today: Proceedings journal homepage: www.elsevier.com/locate/matpr

Mechanical properties of graphene and nano-diamond reinforced ultra high molecular weight polyethylene Nilesh Dalai a,b, P.S. Rama Sreekanth b,⇑ a b

School of Mechanical Engineering, National Institute of Science & Technology (Autonomous), Berhampur, Odisha 761008, India School of Mechanical Engineering, VIT-AP University, Amaravati, A.P. 522337, India

a r t i c l e

i n f o

Article history: Received 20 November 2019 Received in revised form 13 January 2020 Accepted 17 January 2020 Available online xxxx Keywords: Ultra high molecular weight polyethylene Hardness Bending Nanocomposite Graphene Nano-diamond

a b s t r a c t Nano-material reinforced ultra high molecular weight polyethylene (UHMWPE) composites are generally used as a joint replacement material. An investigation has been done on Hardness and 3-point bending of ultra high molecular weight polyethylene (UHMWPE) which was loaded with Nano-diamond (ND) and Graphene (Gr). In order to perform some mechanical tests a UTM test equipment and hardness test equipment were utilized. Due to the formation of a good molecular bonding, there is a significant increase in hardness from 51 HV for neat UHMWPE to 57 HV at 0.5 wt% ND loading of ND/UHMWPE nanocomposites and 54 HV at 0.3 wt% Gr loading of Gr/UHMWPE nanocomposites. At 0.5 wt% of Gr loading, the highest value of the flexural modulus (3750 N/mm2) is observed. When 0.5 wt% of Gr and 0.3 wt% of ND is added, then there is a significant increase in ultimate flexural strength and flexural modulus by loading of nano fillers. In this study the fabrication of ND/UHMWPE and Gr/UHMWPE nanocomposites exhibited good mechanical properties and they can be explode for total joint replacement. Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the First International conference on Advanced Lightweight Materials and Structures.

1. Introduction Among the available thermoplastic polymer, ultra-high molecular weight polyethylene (UHMWPE) is a one of the polymer with excellent mechanical and physical properties. UHMWPE is used in a wide series of technical applications such as field of medicine and engineering field [1]. Because of high hardness, low wear rate and toughness; there is an enormous chance for improving its properties for the application of biomedical material. Various alternatives methods are used to achieve good wear resistance & lifetime improvement of the implant. Cross-linking improves the wear properties of UHMWPE both in-vitro and invivo. cross-linking increases the chance of oxidation, which cause decrease in mechanical properties such as toughness, hardness, modulus of elasticity, yield and ultimate tensile strength [2–5]. Reinforcement of nanofillers is another method to achieve the mechanical properties, reducing wear rate and imparting new properties for UHMWPE polymer. Carbon allotropes such as Multi wall carbon nanotube (MWCNT), carbon nanotubes (CNT), Gra-

⇑ Corresponding author. E-mail address: [email protected] (P.S.R. Sreekanth).

phene (Gr) and Nano diamond (ND) represent an attractive option for enhancing the material property such as mechanical, electrical and thermal of polymeric nanocomposites [6–10,15]. A significant increase of 89% in hardness of pure UHMWPE was observed with well dispersion of 2 wt% MWCNT and c irradiation dose of 100 kGY [3]. The mechanical properties of Pure UHMWPE and nanofiller composite were increase after the irradiation but gradually decreased with respective to time. The presence of MWCNT restricted the ageing of UHMWPE [5], improved the thermal stability and decreased the coefficient of thermal expansion [18]. The yield stress, ultimate stress, fracture strain, hardness and toughness increased 44%, 93%, 70%, 75% and 176% respectively with 2 wt% of MWCNT [9]. The storage modulus increased by 139%, while the loss modulus and damping factor reduced by 71.6% and 27.3% respectively with 2% of MWCNT. But when the 100 kGY irradiation on 2 wt% MWCNT composite, it was found loss modulus and damping factor was increased 69 and 74.7% while storage modulus decreased by 83% as compared to pure UHMWPE [14]. The yield strength and elastic modulus improved by 21% and 30% with addition of 1.0 & 0.5 wt% of graphene nano particles. The ultimate tensile strength and fracture toughness decrease above 0.5 wt% of graphene nanofiller [8]. The hardness and elastics modulus increase 30% and 10% respectively when coating of 2–5 wt% of

https://doi.org/10.1016/j.matpr.2020.01.350 2214-7853/Ó 2020 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the First International conference on Advanced Lightweight Materials and Structures.

Please cite this article as: N. Dalai and P. S. R. Sreekanth, Mechanical properties of graphene and nano-diamond reinforced ultra high molecular weight polyethylene, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.01.350

2

N. Dalai, P.S.R. Sreekanth / Materials Today: Proceedings xxx (xxxx) xxx

graphene used and show 40% low friction as compared to virgin UHMWPE [17]. The storage modulus, tensile strength, scratch hardness and shore D hardness was increased by 106, 33, 66.9, and 28.9% respectively with incorporation of 2 wt% of ND. The surface modified ND enhance the tensile strength and storage modulus by 86 and 124% respectively [13]. The yield strength and elastic modulus was increased by 31% and 101% with 0.5 wt% of GNP [16]. The wear rate and friction was reduced by 72% and 24% respectively when 1 wt% of nanodiamond mixed with UHMWPE [11]. The Slithering wear performance was improved when 0.1 and 0.5 wt% of Carbon Nano tube was used [7]. The wear factor reduced by 80% and 68% under lubrication and dry condition with 2% of MWCNT for 60 min of 100 kGY irradiation [12]. The water contact angle gradually decrease with increase in filler wt% of MWCNT with 100 kGY of irradiation for 60 min [12]. The coefficient of friction, decreased by 50% with 1 wt% GNP [16]. The aim of the present study is to produce nano diamond (ND) and graphene (Gr) reinforced UHMWPE nano composites and to investigate their mechanical properties by changing the weight proportion (wt%) of Gr and ND. The present experimental study describes the fabrication of Gr and ND reinforced UHMWPE nano composites with a view to finding the mechanical properties of the prepared nano composites. The role of nano filler wt% of Gr and ND loading on the mechanical properties of UHMWPE is also examined. 2. Materials & methods 2.1. Materials The UHMWPE was purchased from M/s Lyondellbasell, grade Lupolen UHM 5000 having the average particle size 500 mm and the density of 0.931 g/cm3. Graphene nanoparticles was received from M/s Graphene Super Market, having bulk density-0.30 g/cc, average diameter X &Y dimensions-10–15 mm, average thickness Z Dimension-10–15 nm, average number of Layer 10–15, surface area-112 m2/g. Nano-Diamond Powder was purchased from M/s Nano Shel having purity >75.65%, molecular weight-12.01 g/mol, true density: 3.05–3.3 g/cm3, bulk density: 0.16–0.18 g/cm3, surface area: 200–450 m2/g. Ultra-high molecular weight polyethylene powder (UHMWPE, Lupolen UHM 5000 by Lyondellbasell) was mixed and reinforced with Graphene nanoparticles (Graphene Super Market, Ultrananotech Pvt. Ltd.) and Nano-Diamond Powder (NanoShel, Intelligent Material Pvt. Ltd.).

Table 1 Fabricated composites compositions. Composites (Description)

UHMWPE (wt%)

Graphene (wt%)

NanoDiamond (wt%)

(UHMWPE) UHMWPE + Graphene Nanoparticles (UHMWPE + 0.1 Gr) UHMWPE + Graphene Nanoparticles (UHMWPE + 0.3 Gr) UHMWPE + Graphene Nanoparticles (UHMWPE + 0.5 Gr) UHMWPE + Graphene Nanoparticles (UHMWPE + 0.7 Gr) UHMWPE + Nano-Diamond (UHMWPE + 0.1 ND) UHMWPE + Nano-Diamond (UHMWPE + 0.3 ND) UHMWPE + Nano-Diamond (UHMWPE + 0.5 ND) UHMWPE + Nano-Diamond (UHMWPE + 0.7 ND)

100 99.9

– 0.1

– –

99.7

0.3



99.5

0.5



99.3

0.7



99.9



0.1

99.7



0.3

99.5



0.5

99.3



0.7

2.3. Hardness measurements The hardness tests were carried out on a FSA micro-Vicker hardness tester, using a 3-side pyramid angle of 136°. The hardness tests were performed in the room temperature on the UHMWPE composite samples. For measurements, the particular samples were placed on the and a load of 0.3 kg is applied for a period 5 s. 2.4. Flexural test Flexural properties were examined using three-point bending tests. By taking the nominal dimension (113 mm long, 8 mm wide and 3 mm thick) into consideration the bending samples were designed. The average values were given, by taking three specimens from each set of parameters. Tinius Olsen UTM fitted with a 10 kN load cell, was used to perform the flexural test. The span length of 40 mm was used at a constant cross-head speed of 2 mm/min. The test is forced to stop, when the load is dropped to 40% but the sample has not failed. In this study, while performing the three-point bending tests, none of the sample was ruptured. 3. Results & discussion

2.2. Composite fabrication 3.1. Hardness measurements Fabrication of Graphene/Diamond reinforced UHMWPE nanocomposites is done by ball milling which was followed by the compression molding method. Ball milling is a technique which usually deals with the reduction of the size of ceramics, polymer and minerals. UHMWPEbased composites were obtained by using a horizontal axis ball milling. The UHMWPE powder with predetermined filler content were ball milled with charge to ball ratio as 1:10 at an RPM of 300 for 60 min. The milling process was halted after every 30 min to prevent the heating of the charge. The obtained composite powder was processed in a compression molding machine under 10 MPa for 45 min [9]. The temperature of upper platen was maintained at 210 °C and that of lower platen was maintained at 190 °C. Similar procedure was followed in order to prepare all of the UHMWPE nano-composites with 0.1 wt%, 0.3 wt%, 0.5 wt%, 0.7 wt% and loading of Graphene & Nano-diamond. Samples were cut for various testing based on relevant standards. The fabricated composite composition are given on the Table 1.

Fig. 1 shows the hardness value for all the composites. Fig. 1 shows that ND/UHMWPE composite has higher hardness, which indicates that the material has high wear resistance. This is attributed to the fact that there is load transfer to this filler. Incorporation of the filler into the polymer matrix enhanced the stiffness of the material. The higher the percentage of the filler incorporated, the harder the material, and the more rigid it becomes. It is also observed that as the nanofiller content increases material hardness decrease suddenly. The ND/UHMWPE composite and Gr/UHMWPE composite shows optimum hardness at the filler content of 0.5% and 0.3% respectively. The hardness of different composite are given on the Table 2. 3.2. Flexural test Figs. 2(a) and 2(b) shows the Flexural stress value for Gr/ UHMWPE & ND/UHMWPE composites. It is observed that the flex-

Please cite this article as: N. Dalai and P. S. R. Sreekanth, Mechanical properties of graphene and nano-diamond reinforced ultra high molecular weight polyethylene, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.01.350

3

N. Dalai, P.S.R. Sreekanth / Materials Today: Proceedings xxx (xxxx) xxx

Fig. 2b. Flexural stress of ND/UHMWPE composite.

structure. In the present study graphene used, which is reported to exhibit high flexural modulus, which could also be the possible reason for high flexural stress. From the result, it can be observed graphene composite having high flexural stress which is direct indication of flexural modulus. The flexural modulus of different composite are given in the Table 3.

Fig. 1. Hardness of different composite.

Table 3 Flexural modulus of different composite.

Table 2 Hardness of different composite. Composition

Pure UHMWPE(HV)

ND/UHMWPE(HV)

Gr/UHMWPE(HV)

0.0% 0.1% 0.3% 0.5% 0.7%

51 – – – –

– 52.2 55 57 54

– 51.8 54 54 51

Composition

Pure UHMWPE (N/ mm2)

ND/UHMWPE (N/ mm2)

Gr/UHMWPE (N/ mm2)

0.0% 0.1% 0.3% 0.5% 0.7%

2220 – – – –

– 2310 3150 2480 2440

– 2710 2830 3810 3470

ural stress of different composite sample is increasing as the reinforcement increases irrespective of composite combination. Gr/ UHMWPE composite sample has shown high Flexural strength when compared to ND/UHMWPE composite. Graphene composite exhibiting high flexural stress due to its multilayer and atomic

Fig. 2a. Flexural stress of Gr/UHMWPE composite.

Fig. 3. Flexural modulus of different composite.

Please cite this article as: N. Dalai and P. S. R. Sreekanth, Mechanical properties of graphene and nano-diamond reinforced ultra high molecular weight polyethylene, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.01.350

4

N. Dalai, P.S.R. Sreekanth / Materials Today: Proceedings xxx (xxxx) xxx

0.3% of filler loading. It was observed that after the certain limit the ultimate flexural modulus decrease with increasing in filler content. The ultimate flexural stress of different composite are given on the Table 4. 4. Conclusion This paper reports the effects of nano fillers such as Graphene & Nano-diamond on the mechanical properties of different UHMWPE. Incorporation of fillers has enhanced the mechanical properties such as hardness, flexural stress, & flexural modulus of composites. Optimum graphene content was identified as 0.5 wt %, while nano-diamond has shown optimum at 0.3 wt%. Due to its superior hardness, the nanocomposites are expected to enhance the wear resistance of the UHMWPE. CRediT authorship contribution statement

Fig. 4. Ultimate flexural stress of different composite.

Nilesh Dalai: Formal analysis, Methodology, Software, Writing original draft. P.S. Rama Sreekanth: Visualization, Investigation, Supervision, Writing - review & editing. Declaration of Competing Interest

Table 4 Ultimate flexural stress of different composite. Composition

Pure UHMWPE (N/mm2)

ND/UHMWPE (N/mm2)

Gr/UHMWPE (N/mm2)

0.0% 0.1% 0.3% 0.5% 0.7%

31.9 – – – –

– 32.2 46.1 36.0 35.4

– 39.8 42.4 54.4 48.5

Fig. 3 shows the comparison between Flexural modulus value for Gr/UHMWPE & ND/UHMWPE composites with various filler content. It can be observed that with increase in filler percentage the flexural modulus increase. The flexural strength could be attributed to the better rigidity and stiffness as a result of fair distribution and dispersion of filler in the polymeric matrix, which efficiently hinders chain movement during the deformation. Overall the increase in flexural strength is found to be increased as compared to virgin UHMWPE. The graphene based composites shows better flexural modulus at 0.5% of filler addition where as nanodiamond based composites shows at 0.3% of filler loading. It was observed that after the certain limit the flexural modulus decrease with increasing in filler content. Fig. 4 shows the comparison between Ultimate Flexural stress value for Gr/UHMWPE & ND/UHMWPE composites with various filler content. It can be observed that with increase in filler percentage the ultimate flexural modulus increase. The graphene based composites shows better flexural modulus at 0.5% of filler addition where as nano-diamond based composites shows at

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. References [1] Steven M. Kurtz, The UHMWPE Handbook Ultra-High Molecular Weight Polyethylene in Total Joint Replacement, 2004. [2] G. Lewis, Properties of Crosslinked Ultra-High-Molecular-Weight Polyethylene, 2001. [3] P.S.R. Sreekanth, S. Kanagaraj, Wear 334–335 (2015) 82–90. [4] J.M. Hofsté, B. Van Voorn, A.J. Pennings, Polym. Bull. 38 (1997) 485–492. [5] P.S. Rama Sreekanth, S. Kanagaraj, J. Mech. Behav. Biomed. Mater. 21 (2013) 57–66. [6] G. Wypych, Handbook of Fillers, 1999. [7] B. Suresha, B. Harshavardhan, A.M. Rao, U.R. Koushik, R. Hemanth, Mater. Today Proc. (2019). [8] F. Alam, M. Choosri, T.K. Gupta, K.M. Varadarajan, D. Choi, S. Kumar, Mater. Sci. Eng. B: Solid-State Mater. Adv. Technol. 241 (2019) 82–91. [9] P.S. Rama Sreekanth, S. Kanagaraj, J. Mech. Behav. Biomed. Mater. 18 (2013) 140–151. [10] P. Karami, S. Salkhi Khasraghi, M. Hashemi, S. Rabiei, A. Shojaei, Adv. Colloid Interface Sci. 269 (2019) 122–151. [11] A. Golchin, A. Villain, N. Emami, Tribol. Int. 110 (2017) 195–200. [12] N.N. Kumar, S.L. Yap, F.N.D. bt Samsudin, M.Z. Khan, R.S.P. Srinivasa, Polymers (Basel) 8 (2016) 1–15. [13] S.A. Haddadi, A.R. Ahmad, M. Amini, A. Kheradmand, Mater. Today Commun. 14 (2018) 53–64. [14] P.S. Rama, Sreekanth, N. Naresh, Kumar, S. Arun, S. Kanagaraj, Mater. Res. Innov. 20 (2016) 198–205. [15] H. Tinwala, S. Wairkar, Mater. Sci. Eng., C 97 (2019) 913–931. [16] S. Mohseni, Taromsari, M. Salari, R. Bagheri, M.A. Faghihi Sani, Compos. Part B: Eng. 175 (2019) 107181. [17] A. Chih, A. Ansón-Casaos, J.A. Puértolas, Tribol. Int. 116 (2017) 295–302. [18] P.S. Rama Sreekanth, S. Kanagaraj, Bull. Mater. Sci. 37 (2014) 347–356.

Please cite this article as: N. Dalai and P. S. R. Sreekanth, Mechanical properties of graphene and nano-diamond reinforced ultra high molecular weight polyethylene, Materials Today: Proceedings, https://doi.org/10.1016/j.matpr.2020.01.350