Reinforcement of Rubber through Short Individual Filaments

1976 ◽  
Vol 49 (2) ◽  
pp. 379-389 ◽  
Author(s):  
A. P. Foldi
Keyword(s):  
High Stress ◽  
Penetration Resistance ◽  
Special Treatment ◽  
Poly Vinyl Alcohol ◽  
Elongation At Break ◽  
Green Strength ◽  
Aspect Ratios ◽  
Degree Of Orientation ◽  
High Degree ◽  
Heat Buildup

Abstract Short, individual filaments of seven organic fibers, along with glass and wire, were mixed into several types of rubber stock, mainly on a rubber mill. Both the glass and the wire filaments broke into fragments. A high degree of orientation was achieved with most organic fibers. The presence of these filaments caused, in the direction of orientation, increased green strength (up to 37×) and exceptionally high stress at low elongations (e.g. 5.8 MPa at 100% with only 5 phr fiber). This was accompanied by moderate reduction in uncured yield elongation and by substantial decrease in cured elongation at break. Hardness, both uncured and cured, increased moderately, while heat buildup rose considerably in the presence of fibers. Penetration resistance, measured by a new laboratory test, increased two- to fourfold. The magnitude of these effects was directly proportional to the amount of well-dispersed and oriented fiber. No adhesive coating or special treatment was needed at the aspect ratios studied (> 180) to achieve tensile reinforcement with the organic fibers. The use of an adhesive dip on nylon actually reduced the level of reinforcement. The effects of staple length were insignificant on cured modulus, elongation at break, heat buildup, or penetration resistance; minor on green strength; moderate on Mooney viscosity. The most promising reinforcing filaments were the aramids, nylon, poly(vinyl alcohol), and polyester with aspect ratios between 180 and 3100.

Short Silk Fiber Reinforced Natural Rubber Composites

1983 ◽  
Vol 56 (4) ◽  
pp. 808-826 ◽  
Author(s):  
D. K. Setua ◽  
S. K. De
Keyword(s):  
Silk Fiber ◽  
Tensile Failure ◽  
Mechanical Anisotropy ◽  
Fiber Reinforced ◽  
Bonding Agents ◽  
Elongation At Break ◽  
Green Strength ◽  
Bonding System ◽  
Natural Rubber Composites ◽  
Heat Buildup

Abstract (1) The resorcinol-hexa-silica bonding system is essential for NR-silk fiber systems. (2) Mechanical anisotropy is observable only at higher fiber loadings (20 phr and above) in NR-silk fiber systems. (3) In composites containing a sufficient amount of bonding agents and fibers for tensile anisotropy to be observed, tensile failure occurs by both fiber breakage and debonding. (4) Addition of silk fiber to NR causes (a) increase in hardness, (b) reduction in resilience and elongation at break, (c) increase in heat buildup and set, and (d) increase in tear resistance. (5) The aging resistance of silk fiber-reinforced NR composites is excellent only beyond a fiber loading of 20 phr. (6) Mill shrinkage and green strength of NR improve, while Mooney viscosity and scorch time increase with the addition of silk fiber to NR.

Cellulose Based Electrospun Nanofilters: Perspectives On Tannery Effluent Waste Water Treatment

2021 ◽  
Author(s):  
Senthil Rethinam ◽  
Sardar Batıkan Kavukcu ◽  
Thiagarajan Hemalatha ◽  
A.Wilson Aruni ◽  
Aylin Sendemir
Keyword(s):  
Metal Ions ◽  
Waste Water Treatment ◽  
Toxic Metal ◽  
Poly Vinyl Alcohol ◽  
Tannery Effluent ◽  
Tea Leaves ◽  
Leather Industry ◽  
Elongation At Break ◽  
Hazardous Metal ◽  
Effluent Waste

Abstract Development of nanofilters with the capability to remove toxic metal ions from effluent wastewater will be of immense help to the leather industry. In this study, fibrous nanofilter (FNF) was prepared using micro cellulosic fiber (MCF) and tea leaves microparticles (TLM) blended in poly (vinyl) alcohol (PVA). FNF was analysed for its efficacy to remove hazardous metals from tannery effluent wastewater. The FNF had promising traits of tensile strength (19.24+0.05 Mpa), elongation at break (22.31+0.12 %), flexibility (10.88+0.05 %), water absorption (37.86+0.14 %) and desorption (32.54+0.33 %). The metal adsorption studies clearly reflected the removal of toxic Cr (VI) ions from the effluent water by FNF. The study establishes an economically feasible and highly efficient way to remove hazardous metal ions from effluent wastewater.

Characterization of EVA Residues from the Shoe Industry and Post-Consumer Urban-Waste Polyethylenes

2005 ◽  
Vol 24 (3) ◽  
pp. 139-158 ◽  
Author(s):  
A.J. Zattera ◽  
O. Bianchi ◽  
R.V.B. Oliveira ◽  
L.B. Canto ◽  
C.A. Ferreira ◽  
...  
Keyword(s):  
Tensile Modulus ◽  
Urban Waste ◽  
Elongation At Break ◽  
Shoe Industry ◽  
Izod Impact ◽  
Lower Elongation ◽  
Mechanical Tensile ◽  
High Degree ◽  
Tga And Dsc

This paper presents a characterization of a crosslinked EVA residue (EVA-c) from expanded sheets used in the shoe industry and post-consumer urban-waste polyethylenes regarding their molecular (FTIR), mechanical (tensile and impact tests), morphological (SEM), thermal (DSC, TGA) and dynamic-mechanical (DMTA) properties. For comparison, the properties of the EVA-c and recycled polyethylenes are compared to respective virgin polymers. The recycled polyethylenes generally presented similar properties to the virgin ones. On the other hand, some EVA-c properties differed from virgin ones since it has a high degree of crosslinking and it therefore has a higher tensile modulus and lower elongation at break, notched Izod impact strength and hardness. Additionally, crosslinking was also found to modify the thermal properties (TGA and DSC) of EVA-c.

scholarly journals Social Roles as Viewed by Speakers of Non-Cognate Languages.

2020 ◽  
Vol 3 (4) ◽  
pp. 71-83
Author(s):  
Olga Leonidovna Byessonova ◽  
◽  
Keyword(s):  
Native Speakers ◽  
Social Roles ◽  
Men And Women ◽  
Professional Activities ◽  
Male Roles ◽  
The Family ◽  
Degree Of Orientation ◽  
Native Speakers Of English ◽  
The Public Sphere ◽  
High Degree

Introduction. The article addresses the reflection of ideas about gender social roles in the conceptual and linguistic worldview of men and women. Materials and methods. The analysis is based on the material of the linguistic experi-ment conducted with native speakers of such English and Ukrainian. Results. The results of the experiment reveal the differences in the perception by the native speakers of English and Ukrainian of gender social roles. As the analysis of the material shows, in the Ukrainian society, the public sphere is associated to a greater de-gree with the professional activities of men and women, and there is a high degree of orientation of women towards motherhood. In English, outside the family, mainly male roles are defined, and the roles of women are mainly family and are in the sphere of personal, emotional ties. Discussion and Conclusions. The analysis of social roles shows that the Ukrainian lin-guistic community, to a greater extent than the English-speaking, is characterized by an orientation towards the traditional patriarchal family, in which a woman is the keeper of the hearth, the organizer of male consumption, and the man is the owner and head of the family. The results obtained in the course of the experiment enable to establish a systemic cor-relation between the language structure and the social structure, to establish correla-tions between the language phenomena and the gender of the communicants.

scholarly journals The orientation of iron–sulphur clusters in membrane multilayers prepared from aerobically-grown Escherichia coli K12 and a cytochrome-deficient mutant

1980 ◽  
Vol 190 (2) ◽  
pp. 385-393 ◽  
Author(s):  
Haywood Blum ◽  
Robert K. Poole ◽  
Tomoko Ohnishi
Keyword(s):  
Magnetic Field ◽  
Escherichia Coli ◽  
Cytoplasmic Membrane ◽  
Deficient Mutant ◽  
E Coli ◽  
Membrane Particles ◽  
Degree Of Orientation ◽  
High Degree ◽  
Cytochrome Content ◽  
The Magnetic Field

1. Membrane particles prepared from ultrasonically-disrupted, aerobically-grown Escherichia coli were centrifuged on to a plastic film that was supported perpendicular to the centrifugal field to yield oriented membrane multilayers. In such preparations, there is a high degree of orientation of the planes of the membranes such that they lie parallel to each other and to the supporting film. 2. When dithionite- or succinate-reduced multilayers are rotated in the magnetic field of an e.p.r. spectrometer, about an axis lying in the membrane plane, angular-dependent signals from an iron–sulphur cluster at gx=1.92, gy=1.93 and gz=2.02 are seen. The g=1.93 signal has maximal amplitude when the plane of the multilayer is perpendicular to the magnetic field. Conversely, the g=2.02 signal is maximal when the plane of the multilayer is parallel with the magnetic field. 3. Computer simulations of the experimental data show that the cluster lies in the cytoplasmic membrane with the gy axis perpendicular to the membrane plane and with the gx and gz axes lying in the membrane plane. 4. In partially-oxidized multilayers, a signal resembling the mitochondrial high-potential iron–sulphur protein (Hipip) is seen whose gz=2.02 axis may be deduced as lying perpendicular to the membrane plane. 5. Appropriate choice of sample temperature and receiver gain reveals two further signals in partially-reduced multilayers: a g=2.09 signal arises from a cluster with its gz axis in the membrane plane, whereas a g=2.04 signal is from a cluster with the gz axis lying along the membrane normal. 6. Membrane particles from a glucose-grown, haem-deficient mutant contain dramatically-lowered levels of cytochromes and exhibit, in addition to the iron–sulphur clusters seen in the parental strain, a major signal at g=1.90. 7. Only the latter may be demonstrated to be oriented in multilayer preparations from the mutant. 8. Comparisons are drawn between the orientations of the iron–sulphur proteins in the cytoplasmic membrane of E. coli and those in mitochondrial membranes. The effects of diminished cytochrome content on the properties of the iron–sulphur proteins are discussed.

Interactions between PA6 Ratio and Tensile Properties in PVA/PA6 Hybrid Nanofiber Yarns

2017 ◽  
Vol 14 ◽  
pp. 25-37 ◽  
Author(s):  
Aref Fakhrali ◽  
Seyed Vahid Ebadi ◽  
Ali Akbar Gharehaghaji ◽  
Masoud Latifi ◽  
Abdolrasool Moghassem
Keyword(s):  
Electron Microscope ◽  
Tensile Properties ◽  
Hybrid Model ◽  
Polyamide 6 ◽  
Tensile Behavior ◽  
Poly Vinyl Alcohol ◽  
Elongation At Break ◽  
Hybrid Yarn ◽  
Hybrid Nanofiber ◽  
Scanning Electron

In this study, we fabricated poly vinyl alcohol/polyamide 6 (PVA/PA6) hybrid nanofiber yarns and examined the influence of PA6 content on tensile properties of hybrid nanofiber yarns. The surface morphology of nanofiber yarns was studied by scanning electron microscope (SEM). The average diameters of nanofibers in pure PA6 and pure PVA nanofibers yarns were 83±12 nm and 187±21 nm, respectively. The results showed that the strength of hybrid yarns was descending for PA6 contents below 16.5 % and ascending for higher contents. Also, by increasing the PA6 ratio in the hybrid yarn, the elongation at break was decreased. Three various models including: Hamburger, simple rule of mixtures (ROM) and hybrid models were applied to predict the tensile behavior of hybrid yarns. This study showed that neither ROM nor Hamburger’s models were capable of predicting the tensile properties of hybrid yarns. Whiles, hybrid model can predict properties with the lowest error (6.44 % error in strength values and 13.06 % error in elongation values prediction). Moreover, this model was modified further for higher performance. Our results demonstrate that the hybrid model can be applied in engineered tensile properties of nanofibrous yarns.

Green Strength in Emulsion SBR

1978 ◽  
Vol 51 (5) ◽  
pp. 872-887 ◽  
Author(s):  
E. J. Buckler ◽  
G. J. Briggs ◽  
J. R. Dunn ◽  
E. Lasis ◽  
Y. K. Wei
Keyword(s):  
Weight Fraction ◽  
Full Scale ◽  
High Molecular Weight Fraction ◽  
Stress Strain ◽  
Green Strength ◽  
Chemical Effects ◽  
Base Polymer ◽  
Halide Salts ◽  
High Degree ◽  
Stock Behavior

Abstract The present study and that published previously show that crosslinks based on quaternary ammonium halide salts introduced into emulsion SBR-type polymers confer green strength on blends with other compatible rubbers. The crosslink density employed did not exceed 1 link per 3000 combined monomer groups, equivalent to two links per weight-average polymer chain. Judging by the positive slopes of stress-strain curves, green strength obtained in this manner will persist up to at least 50°C. The crosslinks can be broken by mechanical shear and will re-form under resting conditions during times ranging from days at room temperature to minutes at 150°C. Prolonged mechanical shear in laboratory mixing equipment causes progressive loss of modulus and reduction in the slope of the stress-strain curves of compounds containing these labile crosslinks. Similar effects are observed in corresponding control compounds containing no labile crosslinks, but the initial advantage of the crosslinked compounds is progressively reduced and may be lost if shearing is sufficiently prolonged. Available evidence suggests that the principal cause of loss of modulus through shear is selective breakdown of the high molecular weight fraction of the base polymer. The breakdown of the longer chains, which are those most likely initially to carry three or more crosslinks, eliminates most of the network structure responsible for enhanced modulus. Whether chemical effects contribute to loss of modulus remains to be determined, but the evidence suggests that any such effects will be of lesser importance. Because the shear encountered in small laboratory mixing devices differs from that in full-scale factory equipment and stress-strain curves may not reliably predict green-stock behavior, the significance of the present findings can only be determined by factory trials. It is evident, however, that for the most efficient utilization of high green-strength SBR, exposure of the crosslinked SBR component to mechanical shear during mixing should be held to a minimum. On the other hand, to achieve smooth sheets or profiles at the forming stage, the final compound should be subjected briefly to a high degree of shear at as low a temperature as practicable, to break the labile crosslinks in the stock. Green strength will be recovered during subsequent rest periods. The present study suggests that these conditions should be readily achieved in a calendering operation, such as normally used for preparing carcass plies. However, to a greater extent than in most polymer developments, the final proving ground for applications for this new modification of SBR must be full-scale factory trials.

Anisotropy in Thermal, Electrical and Mechanical Properties of Spin-Coated Polymer Dielectrics

1994 ◽  
Vol 338 ◽  
Author(s):  
Sue Ann Bidstrup ◽  
Thomas C. Hodge ◽  
Linda Lin ◽  
Paul A. Kohl ◽  
J.B. Lee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Three Dimensional ◽  
Interlayer Dielectrics ◽  
Polymer Dielectrics ◽  
Degree Of Orientation ◽  
High Degree ◽  
Interconnection Structure

ABSTRACTIn MCM-D applications, interlayer dielectrics separate and insulate metal conductors to form a three-dimensional interconnection structure. Due to the three-dimensional nature of these structures, the thermal, electrical and mechanical properties of the dielectricmaterials must be known for all orientations in order to correctly design and simulate devices. The most commonly used polymer in microelectronics, polyimide, exists in formulations which have been shown to have a high degree of orientation and exhibit anisotropicproperties.

Preparation and Properties of Bagasses Cellulose Microcrystal Reinforced Poly(Vinyl alcohol) Composite Film

2011 ◽  
Vol 399-401 ◽  
pp. 381-384
Author(s):  
Chun Guang Li ◽  
Bin Guo Zheng ◽  
Wei Gong Peng ◽  
Wei Tian ◽  
Rui Zhang
Keyword(s):  
Thermal Properties ◽  
Composite Film ◽  
Tensile Properties ◽  
Microcrystalline Cellulose ◽  
Vinyl Alcohol ◽  
Composite Films ◽  
Poly Vinyl Alcohol ◽  
Elongation At Break ◽  
Biodegradable Composite ◽  
Cellulose Microcrystal

The biodegradable composite films were prepared from bagasse microcrystalline cellulose as filler and poly(vinyl alcohol)(PVA) as polymeric matrix. The crystallinity, the tensile properties and the thermal properties of the composites were tested. Bagasse microcrystalline cellulose was distributed in PVA films as the crystalline state. The results show that the tensile properties and thermal properties were improved with the addition of bagasse microcrystalline cellulose. When bagasse microcrystalline cellulose mass fraction was 5%, both temperature of initial decomposition and maximum weight loss rate of composite film were raised by 11.71°C and 36.86°C, and the tensile strength increased by 17.88%, and the elongation at break increased by 36.62% compared to those of pure PVA.

Sign in / Sign up

Export Citation Format

Share Document