scholarly journals Preparation and tensile properties of guar gum hydrogel films

2019 ◽  
Vol 28 (3) ◽  
pp. 180-186 ◽  
Author(s):  
Daniel Jussen ◽  
Sandeep Sharma ◽  
James K Carson ◽  
Kim L Pickering

Guar gum hydrogels may be dried to form polymer films which have the potential for use as biodegradable alternatives to polymers such as low-density polyethylene. In this study, the tensile strength and tensile modulus of guar gel films having moisture contents ranging between 15% and 18% (wet basis) were measured at a strain rate of 1 mm min−1. Mean tensile strengths of the films ranged between 25 MPa and 40 MPa (dependent on composition) which is of similar magnitude to the tensile strength data for polyethylene and cellophane that are reported in the literature. The mean tensile modulus of the films (1.5–2.5 GPa) was higher than the tensile modulus values reported for low-density polyethylene but comparable to those for cellophane (3 GPa).

2016 ◽  
Vol 29 (12) ◽  
pp. 1641-1655 ◽  
Author(s):  
Koay Seong Chun ◽  
Salmah Husseinsyah ◽  
Nurul Fatin Syazwani

This research focuses on utilization of kapok husk (KH) as a natural filler in linear low-density polyethylene (LLDPE) ecocomposites. The effect of KH content and coupling agent on tensile properties, thermal properties, water absorption behavior, and morphology of ecocomposites were studied. The addition of KH had increased tensile modulus and water absorption of ecocomposites, whereas tensile strength and elongation at break decreased. However, the polyethylene-grafted acrylic acid (PEAA) was used as a polymeric-coupling agent to enhance the properties of LLDPE/KH ecocomposites. The incorporation of PEAA improved the tensile strength, tensile modulus, crystallinity, and thermal stability as well as reduced the water absorption of LLDPE/KH ecocomposites. The improvement of those properties was caused by the enhanced interfacial bonding, which was evidenced by scanning electron microscopy. The Fourier transmission infrared spectra also confirmed the presence of ester linkage between PEAA and KH.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2436
Author(s):  
Abubakar Sadiq Mohammed ◽  
Martina Meincken

Low-cost wood–plastic composites (WPCs) were developed from invasive trees and recycled low-density polyethylene. The aim was to produce affordable building materials for low-cost social housing in South Africa. Both raw materials are regarded as waste materials, and the subsequent product development adds value to the resources, while simultaneously reducing the waste stream. The production costs were minimised by utilising the entire biomass of Acacia saligna salvaged from clearing operations without any prior processing, and low-grade recycled low-density polyethylene to make WPCs without any additives. Different biomass/plastic ratios, particle sizes, and press settings were evaluated to determine the optimum processing parameters to obtain WPCs with adequate properties. The water absorption, dimensional stability, modulus of rupture, modulus of elasticity, tensile strength, and tensile moduli were improved at longer press times and higher temperatures for all blending ratios. This has been attributed to the crystallisation of the lignocellulose and thermally induced cross-linking in the polyethylene. An increased biomass ratio and particle size were positively correlated with water absorption and thickness swelling and inversely related with MOR, tensile strength, and density due to an incomplete encapsulation of the biomass by the plastic matrix. This study demonstrates the feasibility of utilising low-grade recycled polyethylene and the whole-tree biomass of A. saligna, without the need for pre-processing and the addition of expensive modifiers, to produce WPCs with properties that satisfy the minimum requirements for interior cladding or ceiling material.


2020 ◽  
Vol 35 (1) ◽  
pp. 61-70
Author(s):  
Na Young Park ◽  
Young Chan Ko ◽  
Lili Melani ◽  
Hyoung Jin Kim

AbstractFor the mechanical properties of paper, tensile testing has been widely used. Among the tensile properties, the tensile stiffness has been used to determine the softness of low-density paper. The lower tensile stiffness, the greater softness of paper. Because the elastic region may not be clearly defined in a load-elongation curve, it is suggested to use the tensile modulus which is defined as the slope between the two points in the curve. The two points which provide the best correlation with subjective softness evaluation should be selected. Low-density paper has a much lower tensile strength, but much larger elongation at the break. It undergoes a continuous structural change during mechanical testing. The degree of the structural change should depend on tensile conditions such as the sample size, the gauge length, and the rate of elongation. For low-density paper, the tensile modulus and the tensile strength should be independent of each other. The structure efficiency factor (SEF) is defined as a ratio of the tensile strength to the tensile modulus and it may be used a guideline in developing superior low-density paper products.


2020 ◽  
Vol 15 (3) ◽  
pp. 44-49
Author(s):  
Ibiyemi A. Idowu ◽  
Olutosin O. Ilori

The study examined the effect of fillers on the mechanical properties of the recycled low density polyethylene composites under weathered condition with a view of managing the generation and disposal of plastic wastes. Discarded pure water sachets and fillers (glass and talc) were sourced and recycled. Recycled low density polyethylene (RLDPE) and preparation of RLDPE/glass, RLDPE/talc and RLDPE/glass/talc composites were carried out using a furnace at compositions of 0 – 40% in steps of 10% by weight. The mixtures were poured into hand-laid mould. The samples produced were exposed to sunlight for eight (8) weeks and their mechanical properties were studied. The results of mechanical tests revealed that tensile strength decreased with increasing filler loading while impact strength and hardness property increased marginally and considerably with increasing filler loading for all the composites respectively. The study concluded that glass and talc were able to reinforce recycled low density polyethylene under weathered condition. Keywords: Recycled Low Density Polyethylene (RLDPE); Fillers; Glass, Talc; Weathering condition; Sunlight; and Mechanical properties; Tensile strength, Impact and hardness


2011 ◽  
Vol 43 (6) ◽  
pp. 543-558 ◽  
Author(s):  
Z. Chen ◽  
S. Chen ◽  
J. Zhang

The surfactant, sodium dodecylbenzenesulfonate (NaDDBS) and coupling agents, γ-aminopropyltriethoxy sliane (KH550) and isopropyl dioleic(dioctylphosphate) titanate (NDZ101) were used to treat multiwalled carbon nanotubes in this work. The effects of surface modification of multiwalled carbon nanotubes on crystallization behavior, mechanical properties, and electrical properties of low density polyethylene/polyolefin elastomer/multiwalled carbon nanotubes composites were studied. The results showed that NaDDBS, KH550, and NDZ101 had a favorable effect of improving the dispersion of multiwalled carbon nanotubes, but it cannot improve the interfacial interactionbetween multiwalled carbon nanotubes and the matrix. The improvement in dispersion favored the crystallization behavior and mechanical properties. Modified multiwalled carbon nanotubes had a better acceleration nucleation effect than raw multiwalled carbon nanotubes on low density polyethylene/polyolefin elastomer blends at low content (≤1 wt%). The tensile strength of low density polyethylene/polyolefin elastomer/multiwalled carbon nanotubes composites with modified multiwalled carbon nanotubes increased with lower multiwalled carbon nanotubes content (≤1 wt%), and KH550 and NDZ101 led low density polyethylene/polyolefin elastomer/multiwalled carbon nanotubes composites to possess a higher tensile strength than that of NaDDBS with 1 wt% content. NaDDBS, KH550, and NDZ101 had a minor influence on the dielectric properties of the composites and even caused a decrease in the dielectric loss of composites with 10 wt% multiwalled carbon nanotubes content.


2020 ◽  
pp. 089270572094421
Author(s):  
Wagih Abdel Alim Sadik ◽  
Abdel Ghaffar Maghraby El Demerdash ◽  
Rafik Abbas ◽  
Alaa Bedir

The main goal of this work was to assess the technical feasibility of palm rachis (PR) as a reinforcing agent in the production of wood–plastic composites. Recycled linear low-density polyethylene/PR fiber composites were prepared at constant content (3 phc (per hundred compounds)) of maleic anhydride-grafted polyethylene as compatibilizer by melt blending method utilizing a two-roll mill and compression molding. The effect of nanosilica (NS), nanoclay (NC), and hybrid nanoparticles (NSNC) at different concentrations (2, 4, and 6 phc) on mechanical, physical, thermal, and morphological properties was investigated. The results of mechanical properties measurements demonstrated that when 6 phc NS, 4 phc NC, and 4 phc NSNC were added, tensile, modulus strength, and hardness reached their optimum values. At a high level of NC loading (6 phc), the increased populace of NC layers led to agglomeration and stress transfer gets restricted. Elongation at break and Izod impact strength were decreased by the incorporation of different nanoparticles. Water absorption and thickness swelling of prepared composites were found to decrease on the incorporation of NS and NC. In addition, the thermal stability showed slightly improved by the addition of nanoparticles, but there are no perceptible changes in the values of melting temperature by increasing the content of NS and NC or NSNC. Scanning electron microscopy study approved the good interaction of the PR fibers with the polymer matrix as well as the effectiveness of NS and NC in the improvement of the interaction. The finding indicated that wood–plastic composite treated by NS had the highest properties than other composites.


2017 ◽  
Vol 34 (1) ◽  
pp. 27-42 ◽  
Author(s):  
Suthakarn Auksornkul ◽  
Siriwat Soontaranon ◽  
Chonthicha Kaewhan ◽  
Pattarapan Prasassarakich

A series of linear low-density polyethylene films were produced using a three-layer co-extrusion machine. How the blow-up ratio and resin characteristics affected the final film morphology and engineering properties were studied. The crystalline morphology and orientation during the blown film process of the low-density polyethylene film were investigated using small-angle X-ray scattering, transmission electron microscopy and scanning electron microscopy. Increasing the blow-up ratio increased the transverse direction molecular orientation and decreased the machine direction orientation. The resulting low-density polyethylene morphology was a regular lamellar stacking parallel to the machine direction. The film morphology strongly influenced the mechanical properties. Increasing the blow-up ratio from 1.7 to 2.8 decreased the machine direction tensile strength by 14% and increased the transverse direction tensile strength up to 27% for both the low-density polyethylene/1-butene and low-density polyethylene/1-octene co-monomers, while the machine direction tear strength increased up to 36% and the transverse direction decreased by 16%. Moreover, the first and second heating characteristics from differential scanning calorimeter showed the inherent crystallinity change with increasing blow-up ratio for both the low-density polyethylene/1-octene and the low-density polyethylene/1-butene copolymer. The crystalline orientation changes induced with increasing blow-up ratio affected the film water vapor and oxygen permeability.


2020 ◽  
Vol 299 ◽  
pp. 94-99
Author(s):  
Vasily Ovchinnikov ◽  
Elena E. Mastalygina ◽  
Petr Pantyukhov

Polymer composite based on multilayer combined packaging wastes was prepared and investigated. The composite was made of tetrahedral package wastes, where cardboard part was removed. It was found that obtained composite material has blended polymer matrix that consists of low-density polyethylene, high-density polyethylene and polypropylene. Melting temperature of individual polymers in composite shifts to lower temperatures than that of the initial components. It is the evidence of destruction process or interaction between polymers. The hard particles of aluminum and cellulose are uniformly distributed in the composite. For that reason, these particles do not reduce melt fluidity significantly. The tensile strength and elasticity modulus are higher for the obtained material compared to pure polyethylene. The results show a high potential for the use of the developed composite material.


2017 ◽  
Vol 2017 ◽  
pp. 1-9
Author(s):  
Jong Won Kim ◽  
Joon Seok Lee

Polyethylene is one of the most commonly used polymer materials. Even though linear low density polyethylene (LLDPE) has better mechanical properties than other kinds of polyethylene, it is not used as a textile material because of its plastic behavior that is easy to break at the die during melt spinning. In this study, LLDPE fibers were successfully produced with a new approach using a dry-jet wet spinning and a heat drawing process. The fibers were filled with carbon nanotubes (CNTs) to improve the strength and reduce plastic deformation. The crystallinity, degree of orientation, mechanical properties (strength to yield, strength to break, elongation at break, and initial modulus), electrical conductivity, and thermal properties of LLDPE fibers were studied. The results show that the addition of CNTs improved the tensile strength and the degree of crystallinity. The heat drawing process resulted in a significant increase in the tensile strength and the orientation of the CNTs and polymer chains. In addition, this study demonstrates that the heat drawing process effectively decreases the plastic deformation of LLDPE.


2015 ◽  
Vol 815 ◽  
pp. 69-73 ◽  
Author(s):  
Nik Ahmad Faris Nik Abdullah ◽  
Nik Noriman Zulkepli ◽  
Sam Sung Ting ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
...  

The purpose of this study was to determine the effect of treated Cyperus Odoratus (CY) with sodium hydroxide (NaOH) on the properties of biodegradable plastics made from linear low density polyethylene (LLDPE)/CY blends. Alkali treatments for natural fibers can increased adhesion between the hydrophilic fibers and hydrophobic matric. After CY was treated with 5% NaOH solution, it can be seen that the tensile strength and Young’s modulus of the LLDPE/CY blends significantly increased. Therefore, alkali treatments can be considered in modifying the properties of natural fibers.


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