Melt mixed compatibilized polypropylene/clay nanocomposites. II. Dispersion vs. thermal properties, optical transmittance, and fracture behaviors

2011 ◽  
Vol 45 (25) ◽  
pp. 2613-2631 ◽  
Author(s):  
S.-M. Lai ◽  
W.-C. Chen ◽  
X. S. Zhu

Compatibilized polypropylene (PP)/clay nanocomposites using two different types of maleated compatibilizers, polyolefin elastomer-grafted maleic anhydride (POE- g-MA) and PP-grafted maleic anhydride (PP- g-MA), to improve the dispersion of various amounts of commercial organoclay (Closite 20 A) were prepared via a melt-mixing technique. The optical transmittance for the POE- g-MA compatibilized nanocomposites was lower than that of PP- g-MA compatibilized cases, although POE- g-MA greatly increased the interlayer spacing of the clay compared with PP- g-MA. The optical transmittance of POE- g-MA compatibilized cases increased with increasing clay content, as a result from a preferentially POE- g-MA adsorbed onto the surface and edge of clay moiety. PP- g-MA compatibilized system conferred higher tensile strength, Young's modulus, or cutting strength through crystalline yielding effect even at the nanofracture zone of deformation, but lower tear strength than POE- g-MA compatibilized system. The current results suggested that high extent of exfoliation may not guarantee high transparency or strength varied with different deformation behaviors.

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Wasuthep Luecha ◽  
Rathanawan Magaraphan

This research employed a novel and facile approach called nanoclay aerogel masterbatch.. This innovative technique was conducted by attaching the clay layers directly onto a mobile polymer, for example, polyethylene glycol (PEG), in order to modify the clay layer through PEG-clay intercalation and PEG-hydrogen bonding. This state was maintained with a small amount of the anionic polymer hydrogel, for example, kappa-carrageenan (KC), and turning it into a highly porous and fragile structure by freeze-drying, thus a so-called nanoclay aerogel masterbatch. The facile nanoclay aerogel masterbatch was able to be attained even at high clay loadings (55–67 wt.% of the inorganic clay content) with constant PEG and KC loadings. The interlayer spacing enlargement of the nanoclay galleries was around 17 Å with the typical lamellar morphology like a house of cards structure. The density values were within 0.108–0.122 g·cm−3. The thermal stabilities were up to 270°C, revealing better thermal stability for melt mixing with the commodity plastics at a high melting temperature. The flowability and processability were certified by the melt flow index (MFI) results. The highest nanoclay loading capacity (67 wt.%) of the achieved nanoclay aerogel masterbatch was selected to prepare PS-clay nanocomposites via a melt-mixing process. The comparative nanocomposites were produced by using organoclay. The results of the X-ray diffraction (XRD) and transmission electron microscopy (TEM) exhibited that the exfoliated morphologies were obtained at all clay contents (1–3 wt.%); however, the intercalated structure was gained by using organoclay. The outstanding transparency and brightness were remarked from the specimens prepared by using the nanoclay aerogel masterbatch. The brownish specimens were observed by using organoclay. The significant improvements of tensile properties, glass transition temperature (Tg), and thermal stability were noticed from the nanocomposites prepared using the nanoclay aerogel masterbatch.


Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1954
Author(s):  
Yang Liu ◽  
Xun Zhang ◽  
Quanxin Gao ◽  
Hongliang Huang ◽  
Yongli Liu ◽  
...  

In the present study, silver (Ag) nanoparticles and maleic anhydride-grafted polyolefin elastomer (MAH-g-POE) were used as enhancement additives to improve the performance of the polyoxymethylene (POM) homopolymer. Specifically, the POM/Ag/MAH-g-POE ternary nanocomposites with varying Ag nanoparticles and MAH-g-POE contents were prepared by a melt mixing method. The effects of the additives on the microstructure, thermal stability, crystallization behavior, mechanical properties, and dynamic mechanical thermal properties of the ternary nanocomposites were studied. It was found that the MAH-g-POE played a role in the bridging of the Ag nanoparticles and POM matrix and improved the interfacial adhesion between the Ag nanoparticles and POM matrix, owing to the good compatibility between Ag/MAH-g-POE and the POM matrix. Moreover, it was found that the combined addition of Ag nanoparticles and MAH-g-POE significantly enhanced the thermal stability, crystallization properties, and mechanical properties of the POM/Ag/MAH-g-POE ternary nanocomposites. When the Ag/MAH-g-POE content was 1 wt.%, the tensile strength reached the maximum value of 54.78 MPa. In addition, when the Ag/MAH-g-POE content increased to 15wt.%, the elongation at break reached the maximum value of 64.02%. However, when the Ag/MAH-g-POE content further increased to 20 wt.%, the elongation at break decreased again, which could be attributed to the aggregation of excessive Ag nanoparticles forming local defects in the POM/Ag/MAH-g-POE ternary nanocomposites. Furthermore, when the Ag/MAH-g-POE content was 20 wt.%, the maximum decomposition temperature of POM/Ag/MAH-g-POE ternary nanocomposites was 398.22 °C, which was 71.39 °C higher than that of pure POM. However, compared with POM, the storage modulus of POM/Ag/MAH-g-POE ternary nanocomposites decreased with the Ag/MAH-g-POE content, because the MAH-g-POE elastomer could reduce the rigidity of POM.


2007 ◽  
Vol 7 (12) ◽  
pp. 4456-4464 ◽  
Author(s):  
S. M. L. Silva ◽  
M. A. López-Manchado ◽  
M. Arroyo

The effect of different nanofillers and compatibilizers (maleic anhydride-grafted-polypropylene and maleic anhydride-grafted-ethylene propylene diene terpolymer rubber) on the morphology, mechanical, mechanodynamical and thermal characteristics of thermoplastic olefins based on polypropylene and ethylene propylene diene terpolymer rubber blends has been analysed. A better affinity with the matrix and a better dispersion of the nanoparticles is observed in rubber rich matrices. Organoclay, such as Cloisite C15A and Cloisite C20A, treated with a non-polar surfactant give rise to intercalated nanocomposites, and the lower the concentration of surfactant (C20A) the most noticeable increase in interlayer spacing and consequently better properties in the nanocomposites. The maleic anhydride-grafted-ethylene propylene diene terpolymer rubber is a better compatibilizer for organo-clay nanocomposites based on rubber rich matrices.


2014 ◽  
Vol 34 (8) ◽  
pp. 715-726
Author(s):  
Subhendu Ray Chowdhury ◽  
Sanju Francis ◽  
Kuppa Sivasankara Sarma

Abstract A series of nylon 6-clay nanocomposites were prepared by melt mixing, followed by electron beam (EB) crosslinking at various doses. Effects of crosslinking on clay dispersion, gel content, crystallinity and water absorption properties (hygrothermal) were studied. No change of the dispersion pattern of clay in nanocomposites was observed after crosslinking [from X-ray diffraction (XRD) and transmission electron microscopy (TEM)]. Gel content, i.e., degree of crosslinking is seen to keep on increasing with irradiation dose, although clays hinder crosslinking of polymers to some extent. Crystallinity of polymers is reduced after incorporation of clay as well as crosslinks. However, water absorption rate and maximum water content of nanocomposites are found to increase and saturation time to decrease with clay content. However, these changes become opposite after crosslinking of polymers. The water absorption for all samples is noticed to increase with temperature. Thus, EB crosslinking, without affecting the nanocomposite morphology, i.e., properties derived from nano interface generation, decreases the water absorption properties of nanocomposites.


2012 ◽  
Vol 32 (8-9) ◽  
pp. 475-485 ◽  
Author(s):  
Wen-Chih Chen ◽  
Jung-Liang Liu ◽  
Sun-Mou Lai ◽  
Shi-Xian Tang ◽  
Horng Jer Tai ◽  
...  

Abstract Melt mixed metallocene-catalyzed ­polyethylene elastomer (mPE)/clay nanocomposites, using a functionalized polyolefin elastomer (mPE-g-silane) as a compatibilizer, with the addition of the commercial clay with different intercalant types (Cloisite 20A and 30B) were prepared to investigate the importance of interfacial interaction. Cloisite 30B gave a relatively higher polarity than Cloisite 20A, but smaller original d-spacing. According to X-ray diffraction (XRD) and transmission electron microscopy (TEM) results, Cloisite 20A-filled nanocomposites depicted fairly well-dispersed clay within the mPE matrix, except with higher clay content. By contrast, the clay agglomerates were evident for Cloisite 30B-filled cases. A continuous increase of gel content for Cloisite 20A-filled systems was observed, but only a limited variation for Cloisite 30B-filled systems was found. The roles of the polarity degree of the organically modified clay, original d-spacing, and the compatibilizer, were quite essential. Young’s modulus of Cloisite 20A-filled samples increased with increasing clay content, from 23.8±1.3 MPa [0 parts per hundred resins (phr)] to 34.1±2.0 MPa (9 phr), whereas modulus of Cloisite 30B-filled samples did not show a significant variation. The tear strength of Cloisite 20A-filled nanocomposites increased up to two-fold with increasing clay content, reaching 9 phr. Only a slight increase in tear strength of Cloisite 30B-filled nanocomposites was observed. For the cutting strength, Cloisite 20A-filled cases also conferred higher values in comparison with Cloisite 30B-filled cases.


Proceedings ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 6 ◽  
Author(s):  
Heriarivelo Risite ◽  
Hicham Abou Oualid ◽  
Khalil El Mabrouk

The morphology and properties of polypropylene (PP)/organoclay nanocomposites prepared by melt processing were investigated with a special interest on the different effects of the use of different grafted PP as compatibilizers, i.e., maleic anhydride or silane-grafted species, PP-g-MA or PP-g-Si. When either PP-g-MA or PP-g-Si was added, better improvement of properties was achieved. The addition of PP-g-Si was found to increase the crystallization temperature upon the clay addition in comparison to PP-g-MA. Moreover, the PP-g-MA proved to be more efficient than PP-g-Si. The degree of reinforcement was found to be dependent on the interaction forces between the polymer matrix/clay, which resulted in intercalated/partial exfoliated structures for PP-g-Si while increasing clay content induced a change from exfoliated to intercalated using PP-g-MA, as revealed by transmission electron microscopy observations and X-ray diffraction analysis.


2009 ◽  
Vol 112 (6) ◽  
pp. 3597-3604 ◽  
Author(s):  
Sriram Lakshminarayanan ◽  
Bin Lin ◽  
Genaro A. Gelves ◽  
Uttandaraman Sundararaj

2018 ◽  
Vol 877 ◽  
pp. 294-298 ◽  
Author(s):  
Kundan Patel ◽  
Jay Patel ◽  
Piyush Gohil ◽  
Vijaykumar Chaudhary

Composite materials play a vital role in many industrial applications. Researchers are working on fabrication of new composite materials worldwide to enhance the applicability of these materials. The present study aimed to investigate the effect of Nano clay loading as filler on the mechanical properties of the bamboo fiber yarn reinforced polyester composite. Five different types of composite specimen were prepared with Nano clay loadings of 0 to 4 % weight fraction using hand lay-up technique. It was observed that the composite sheet with 1 wt % nano clay content exhibited the optimized tensile and flexural strength. However the mechanical properties tend to decrease with addition of nano clay content from 2 to 4 wt %. In spite of that the values of mechanical properties with 2 and 3 wt % nano clay content is higher than 0 wt % nano clay content.


Author(s):  
A. A. AL-Rawas

Collapsible soils are encountered in arid and semi-arid regions. Such soils cause potential construction problems due to their collapse upon wetting. The collapse phenomenon is primarily related to the open structure of the soil. Several soil collapse classifications based on parameters such as moisture content, dry density, Atterberg limits and clay content have been proposed in the literature as indicators of the soil collapse potential. Direct measurement of the magnitude of collapse, using laboratory and/or field tests, is essential once a soil showed indications of collapse potential. Treatment methods such as soil replacement, compaction control and chemical stabilization showed significant reduction in the settlement of collapsible soils. The design of foundations on collapsible soils depends on the depth of the soil, magnitude of collapse and economics of the design. Strip foundations are commonly used when collapsing soil extends to a shallow depth while piles and drilled piers are recommended in cases where the soil extends to several meters. This paper provides a comprehensive review of collapsible soils. These include the different types of collapsible soils, mechanisms of collapse, identification and classification methods, laboratory and field testing, treatment methods and guidelines for foundation design.


2017 ◽  
Vol 2 (2) ◽  
pp. 37 ◽  
Author(s):  
Antonio Marcelino Silva Filho ◽  
Carlos Leandro Borges Silva ◽  
Marco Antonio Assfalk Oliveira ◽  
Thyago Gumeratto Pires ◽  
Aylton José Alves ◽  
...  

This paper presents the study of the relationship between electrical properties and physical characteristics of the soil. Measures of apparent electrical resistivity of the soil were made for different types of soil, varying moisture content gradually while maintaining a constant compaction, and then varying the compaction and relating it to a constant humidity. Development of a correlation surface is proposed in order to identify granulometry of the soil from moisture and compaction measurements. For the study of spatial variability, two areas were chosen to allow the change of moisture content and compaction in order to verify the measurement capacity of apparent electrical resistivity of the soil as methodology to identify change in soil dynamics. Results obtained show correlations among apparent electrical resistivity of the soil, moisture, soil compaction and clay content.


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