bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Recycling on Fire Retardancy of Intumescent Polypropylene Based Blends
Authors: Almeras Xavier , Le Bras Michel , Hornsby Peter , Bourbigot Serge , Marosi Gyorgy , Anna Peter , Delobel René
Published: September 2018

This work deals with the effect of recycling on halogen-free flame retarded polypropylene blends. The intumescent ammonium polyphosphate/polyamide-6/polypropylene blend is considered. The study of the fire properties using cone calorimeter shows a decrease in the fire performance. Recycling the blends induces chemical modifications of polymer and additives. The chemical modifications due to the recycling are investigated by solid state31P NMR. It is shown that APP is degraded. These modifications induce a loss of the ammonium contents, which could explain the decrease in the fire performance.
Hydrocarbon Mixtures from Waste Polymer Degradation
Authors: Miskolczi Norbert , Bartha László , Deák Gyula , Jóvér Béla , Kalló Dénes
Published: September 2018

The degradation of waste polymers is one of the possible routes of utilization. Various cracking processes are suggested for different waste polymers, when long alkyl chains are degraded and transformed into lighter hydrocarbons. Yields of the liquid and gas reaction products can be increased and composition thereof can be modified by catalysts.

Catalytic cracking of polyolefin waste polymers was studied in a batch reactor without and with Y, FAU (FCC), H-ZSM5 and natural clinoptilolite zeolite catalysts. The additives of the feed polymers did not significantly affect the yields and properties of the products but the type of the catalysts did. Both the gas and liquid yields increased with the catalyst concentration. The activity of the catalysts influenced the yields and the molecular weight of the volatile compounds. In the presence of catalysts both double bond and carbon chain isomerization were observed, but the latter was less significant than the former. The minimum temperature of cracking is lower with catalyst than without catalyst. The grain size of catalyst affects the yields, but less significantly the composition of products.
Optimization of Neutral Hydrolysis Reaction of Post-consumer PET for Chemical Recycling
Authors: Mancini Sandro Donnini , Zanin Maria
Published: September 2018

The neutral hydrolysis reaction of post-consumer poly(ethylene terephthalate) in solid state was studied through the reaction of the polymer with water at the molar ratio 1:91 with autogenous pressure. Two sizes of post-consumer PET flakes and temperatures of 135°C, 170°C and 205°C with pressures of 4.0 atm, 7.5 atm and 13.5 atm, respectively, were considered. With reaction time equal to 6h, the method reached 99% depolymerization at 205°C, 8.2% at 170°C and 1.7% at 135°C. The reaction extension was measured by separating the terephthalic acid formed in the process and calculating by gravimetry how much material could still be reacted. Through the viscosimetry of diluted solutions and the counting of carboxylic end groups in the remaining material from the gravimetric assay, it was possible to suggest that the reaction occurs randomly and in the whole volume of the polymeric particle and not solely on the surface. The terephthalic acid obtained and then purified was characterized by elemental analysis, magnetic nuclear resonance, size and particle size distribution and spectrophotometry in the visible spectrum, and it was similar to the petrochemical equivalent, with purity recorded in carbon base equal to 99.9%.
Pyrolysis of Polypropylene/Polyethylene/Polystyrene and Polyvinylchloride Mixed Plastics using CaCO3
Authors: Bhaskar Thallada , Uddin Azhar , Kaneko Jun , Matsui Toshiki , Muto Akinori , Sakata Yusaku
Published: September 2018

The recycling of halogenated waste plastics poses serious problems. The pyrolysis of PP/PE/PS/PVC was performed by using CaCO3 sorbent to remove the chlorine content during the process. The presence of water (10 wt%) in the plastic mixture did not effect the characteristics of liquid products or the dechlorination efficiency of CaCO3 sorbent. The halogen free liquid products can be used as a feedstock in refinery or fuel oil.
Effect of Silane Coupling Agent on Cure Characteristics and Mechanical Properties of Nitrile Rubber/Reclaimed Rubber Blend
Authors: Nelson P.A. , Kutty S.K.N.
Published: September 2018

Blends of nitrile rubber and reclaimed rubber containing different levels of a coupling agent, Si 69 (bis(3-triethoxysilylpropyl)tetrasulphide) were prepared and the cure characteristics and mechanical properties were studied. Optimum loading of Si-69 was found to be a function of blend ratio. 3 phr of Si 69 in a 70:30. Blend was found to be the optimum combination with respect to the mechanical properties. The rate and state of cure were also affected by the coupling agent. Tensile strength, tear strength and abrasion resistance were improved in the presence of coupling agent. While the state of cure improved, the cure rate and scorch time decreased with increasing silane content. Ageing studies showed that the blends containing the coupling agent were inferior to the unmodified blends.
Use of Marble Waste in the Rubber Industry: Part II (SBR Compounds)
Authors: Agrawal S. , Mandot S. , Bandyopadhyay S. , Mukhopadhyay R. , Dasgupta M. , De P.P. , Deuri A.S.
Published: September 2018

An attempt has been made to utilise marble powder as a filler for rubber. The marble was derived from the slurry produced by a Gangsaw machine while cutting the big marble blocks in north-western India. The marble powder has been used in styrene butadiene rubber (SBR): (1) as a cheapening filler, (2) as a semi-reinforcing filler; this involved chemical treatment of the slurry; and (3) as a partial replacement for carbon black filler, to reduce the cost of the compounds. One other motivation was the need to find a way of disposing of the powder, which is creating a serious threat to the local environment.

The methodology consisted of: (i) collection of the marble powder (ii) its characterisation (iii) its evaluation in rubber compounds (iv) treatment of the marble powder to enhance its reinforcing characteristics both by chemicals and by electron beam (EB) radiation and (v) evaluation of the filled material in end-products.

It was found that the marble powder could be used as a cheapening filler in styrene butadiene rubber, in place of other commercial fillers like whiting. However, no significant improvement was obtained by chemical treatment or by electron beam (EB) radiation of the marble powder. It could be used as a partial replacement for carbon black (up to 10 phr) in various rubber products, which are used under static conditions (not under dynamic situations). These findings were consistent with those previously observed for natural rubber compounds.
Utilization of Waste Paper in the Manufacture of Natural Rubber Composite for Radiation Shielding
Authors: Madani M. , Basta Altaf H. , Abdo A. El-Sayed , El-Saied Houssni
Published: September 2018

Investigations have continued for economic utilization of lignocellulosic waste, which represents one of the environmental problems facing third world countries. In this work, we intended to use old newsprint paper (ONP) as a filler in radiation shielding rubber composite.

In this respect, the treatment of ONP with magnetite was carried out. The effect of incorporating untreated and treated newsprint in the rubber matrix on the swelling, electrical and mechanical properties, as well as gamma and neutron-shielding power has been studied. The changes in physico-mechanical properties of such composites by γ-irradiation were also investigated. This study led to conclusion that composite samples containing 6% wax and 54% newspaper or 18% wax and 42% modified ONP has the higher behavior to γ-irradiation dose. The incorporation of modified waste paper into the rubber matrix increases the conductivity and enhances the mechanical properties of produced composites. At higher non modified and modified newspaper loadings a serious loss of rubber elasticity were noticed.

Composite with good attenuation properties for both gamma rays and thermal neutrons was produced from incorporation of 54% modified newsprint with 6% paraffin wax.
Isora Fibres and their Composites with Natural Rubber
Authors: Mathew Lovely , Joseph K.U. , Joseph Rani
Published: September 2018

This paper reports the use of a natural fibre ‘isora’ as reinforcement for natural rubber. Isora is a bast fibre separated from the bark of the Helicteres isora plant by retting. The effect of different chemical treatments on the fibre properties and on the mechanical performance of short isora fibre reinforced natural rubber (NR) composites has been investigated. The surface modifications carried out in this work include mercerization, acetylation, benzoylation, and treatments with toluene di-isocyanate and a silane. The treated and untreated fibres were characterized by infrared spectroscopy. The spectra indicate a reduction in the lignin content and the introduction of non-polar functional groups on the surface of the fibres. The thermal stability of the untreated and treated fibres was studied by thermogravimetry, which indicated that it could be improved by appropriate chemical treatments. Scanning electron microscopy (SEM) studies were carried out to investigate the fibre surface morphology, fibre pull-out and fibre- rubber interface bonding. SEM gives strong evidence about the nature of the physical and micro structural changes that occurred on the fibre surface on chemical modification. Mechanical properties such as tensile modulus, tensile strength, tear strength etc were measured to investigate the performance of the composites. Many of the properties were superior when the composites contained treated fibres. The improvement in the properties also indicated that the bonding of the NR matrix to isora fibres could be improved by chemical treatment.
Thermoplastic Elastomers by Dynamic Vulcanization
Authors: Naskar K. , Noordermeer J.W.M.
Published: September 2018

The present paper introduces various topics and aspects of dynamic vulcanization as applied to thermoplastic elastomers. The classification of polymer blends and thermoplastic elastomers, the development of thermoplastic vulcanizates, and the use of various types of crosslinking systems (with special emphasis on peroxides/co-agents, and phenolic resins as crosslinking agents for PP/EPDM blends) are reviewed. The morphology and rheology of thermoplastic vulcanizates and their typical end-use applications are also touched upon.
Sandwich Injection Moulding of Thermosetting Materials Part II: Effects of Moulding Parameters
Authors: Kiatmanaroj S. , Goodship V. , Smith G.F.
Published: September 2018

This paper describes experiments on the sandwich injection moulding of two thermosetting polyesters, a powder coating and a bulk moulding compound. The flow of the powder coating in the injection moulding machine at various tool temperatures was investigated in order to find the optimum conditions. The formation of the skin and core layers in the moulding component at various injection times is described and discussed.
Recyclable PP/Polyamide Composite
Authors: Abraham Thomas N , George K.E. , Peijs Ton.
Published: September 2018

A commercial grade of polypropylene matrix reinforced with waste polyamide (nylon 6) fibres of two diameters at levels up to 40wt% (100 polypropylene + 40 polyamide) was studied.

Smaller diameter fibres showed better mechanical properties than larger diameter ones. Attempts were made to improve the interfacial adhesion between the fibres and the matrix by grafting with maleic anhydride and with also styrene maleic anhydride. The mechanical properties showed significant improvements as a result of these modifications. Thermal stability was also marginally improved. These composites could be easily recycled by processing them above the melting point of the reinforcing fibres.
Mechanochemical Devulcanization of Vulcanized Gum Natural Rubber
Authors: Jana G.K. , Das C.K.
Published: September 2018

De-vulcanization of vulcanized elastomers represents a great challenge because of their three-dimensional network structure. Sulfur-cured gum natural rubbers containing three different sulfur/accelerator ratios were de-vulcanized by thio-acids. The process was carried out at 90 °C for 10 minutes in an open two-roll cracker-cum-mixing mill. Two concentrations of de-vulcanizing agent were tried in order to study the cleavage of the sulfidic bonds. The mechanical properties of the re-vulcanized rubber (like tensile strength, modulus, tear strength and elongation at break) were improved with increasing concentrations of de-vulcanizing agent, because the crosslink density increased. A decrease in scorch time and in optimum cure time and an increase in the state of cure were observed when vulcanized rubber was treated with high amounts of de-vulcanizing agent. The temperature of onset of degradation was also increased with increasing concentration of thio-acid. DMA analysis revealed that the storage modulus increased on re-vulcanization. From IR spectroscopy it was observed that oxidation of the main polymeric chains did not occur at the time of high temperature milling. Over 80% retention of the original mechanical properties (like tensile strength, modulus, tear strength and elongation at break) of the vulcanized natural rubber was achieved by this mechanochemical process.
Mixtures of Recycled Milk Pouches with a Virgin LDPE-LLDPE Blend
Authors: Choudhury Arup , Mukherjee Mandira , Adhikari Basudam
Published: September 2018

The present investigation deals with the viability of the use of recycled milk pouch material, which is a 50:50 mixture of LDPE and LLDPE, and the scope for improvement of its properties by combining it with virgin LDPE-LLDPE (50/50). Melt flow index (MFI), rheological properties, thermal and mechanical properties of the pure materials and their formulated blends containing recycled milk pouches were studied. The properties of the recycled materials were not as satisfactory as those of the corresponding virgin materials. But a significant improvement in viscosity, crystallinity, tensile strength and elongation at break of the recycled LDPE-LLDPE material was achieved by blending it with the corresponding virgin LDPE-LLDPE blend.
A New Experimental Procedure for Incorporation of Model Contaminants in Polymer Hosts
Authors: Papaspyrides C.D. , Voultzatis Y. , Pavlidou S. , Tsenoglou C. , Dole P. , Feigenbaum A. , Paseiro P. , Pastorelli S. , de la Cruz Garcia C. , Hankemeier T. , Aucejo S.
Published: September 2018

A new experimental procedure for incorporation of model contaminants in polymers was developed as part of a general scheme for testing the efficiency of functional barriers in food packaging. The aim was to progressively pollute polymers in a controlled fashion up to a high level in the range of 1000 ppm and use them as input for the core layer of a tri-layer package, in order to monitor migration phenomena difficult to study in real conditions. To this end, a contamination recipe was initially formulated by a set of selected surrogates. The experimental procedure developed, led to satisfactory results as far as homogeneity and final concentration in the polymers concerned. High temperature data were also used in order to evaluate the efficiency of typical thermoforming processes in reducing possible volatile and non-volatile substances from recycled polymeric materials.
Analysis of Back Injecting Real Wood Veneers using Engineering Polymers in an Injection Moulding Process
Authors: Makenji K. , Goodship V. , Fanning R. , Buckley S.
Published: September 2018

The current veneering process for interior trim components in the premium car segment involves the use of aluminium or polymeric substrates with thin wood veneers hot embossed to the surface using thermoset adhesives. The alternative process of back injecting real wood veneers with engineering polymer materials is considered here. The main aim of this work was to trial a number of engineering polymeric materials in a simple geometry component. In addition the basic adhesion and dimensional performance was also assessed.

Five engineering polymers were selected and trialled for this process. A cross-section of the parts made were tested to an adhesion delamination test (DIN 53255), all of which passed the test successfully. Dimensional analysis of the mouldings show there is a distinct relationship between component distortion and the shrinkage value for that material, at both post injection moulding and post cooling.

A relationship between the veneer and low polymer shrinkage was shown. The blend polymer, PA + ABS with 15% glass filler performed ideally with dimensional data. This material had the lowest measured shrinkage value of 0.15% and produced the flattest test samples.

The worst dimensionally performing material with veneer was PA 66; which produced dimensional readings approximately three times worse than the PA + ABS 15% GF. This correlated with the polymer shrinkage values for this polymer being the highest recorded from this series of experiments.
A Study on the Use of Castor Oil as Plasticizer in Natural Rubber Compounds
Authors: Raju P. , Nandanan V. , Kutty Sunil K.N.
Published: September 2018

Mechanical properties and thermal degradation of natural rubber compounds containing castor oil were studied to evaluate its suitability as plasticizer. Naphthenic oil was used as a reference plasticizer. The cure time was marginally lower in the case of castor oil mixes, probably due to the presence of free fatty acids in it. The tear strength and modulus were better in the case of mixes containing castor oil, while most of the other mechanical properties were comparable to the mixes containing naphthenic oil. The heat build up and compression set were higher than that of the naphthenic oil mixes. Thermal studies showed an increase of 8 °C in the temperature of initiation of degradation and an increase of 6 °C in the temperature at which the peak rate of degradation occurred. The peak rate of degradation was comparable to that of the reference compound
Recycling of waste RFL (Resorcinol-Formaldehyde Latex) Dip Solid in Natural Rubber-based Ply Skim Compound
Authors: Bandyopadhyay S. , Agrawal S.L. , Ameta R. , Dasgupta S. , Mukhopadhyay R. , Deuri A.S. , Ameta Suresh C.
Published: September 2018

Waste resorcinol – formaldehyde – latex (RFL) dip solid was collected from the suction chamber of a typical tyre industry dip unit. The cure acceleration effect of the waste material was studied in a natural rubber (NR) based filled compound. The effect of the waste material was examined in a natural rubber (NR) based ply skim compound of a bias tyre with cure package modification. Rheological, tack index, stress-strain properties, swell index, dynamic mechanical properties, H-adhesion before and after anaerobic aging was also studied.
Recycled Poly(ethylene terephthalate) Waste Oligomers as Corrosion Inhibitors of Steel
Authors: Atta Ayman M. , El-Sockary Mahar A. , AbdelSalam Samer
Published: September 2018

The corrosion inhibition efficiency of two oligomers, derived from glycolysed products of poly(ethylene terephthalate) with diethanol and triethanol amine, was measured from weight loss and electrochemical polarization techniques. The polarization curves indicate that these oligomers act as mixed-type inhibitors. The inhibition efficiency was increased with increment of inhibitor concentration. The temperature effect on the corrosion behavior of steel in 1M HCl with and without oligomers was studied at different temperatures ranged from 308 to 343 K. The adsorption of inhibitors on the steel surface was increased with increment of the temperature. Some thermodynamic data for the adsorption process were calculated and discussed.
The Effect of Recycling on LDPE Foam Properties
Authors: Kabamba Eddy Twite , Rodrigue Denis
Published: September 2018

The purpose of this work was to investigate the loss of performance undergone by a chemically foamed polymer in a close-loop recycling process. The case of low density polyethylene (LDPE) was studied by foaming up to 10 times the same polymer on an extrusion line using constant processing conditions. After each cycle, the material was characterized in terms of morphological, mechanical, rheological, and thermal properties. In order to detect the effect of foaming itself, the same procedure was applied to unfoamed LDPE. All the results indicate that foamed polymers have higher degradation levels than unfoamed ones when processed under similar conditions.
Evaluation and Monitoring of Natural Rubber Technological Properties of Rubber Tree Clones Recommended for Plantation on the Plateau of São Paulo State, Brazil
Authors: Moreno Rogério M. B. , Gonçalves Paulo S. , Mattoso Luiz H. C.
Published: September 2018

The technological properties from four rubber clones (GT1, PB 235, IAN 873 and RRIM 600) of the Hevea brasiliensis species was studied by the acetone extract percentage, Wallace plasticity (P0), plasticity retention index [PRI (%)] and Mooney viscosity (VR) and correlated with the climatic conditions. The technological properties were performed in the natural rubber in two consecutive years of tappings (40 tappings) for 4 rubber tree clones. The results have shown highly and significant variations among clones and tappings indicating that these variations should be taken into account. The results of multiple regression analysis have shown that the four studied clones have distinct responses due to the environmental variations, the same for performed technological properties. The average value of PRI found for the PB 235 clone was the lowest probably due to its higher values of acetone extract percentage.
Catalytic Depolymerisation of Polystyrene
Authors: Anwar Jamil , Munawar Munawar Ali , Waheed-uz-Zaman  , Dar Amara , Tahira Umbreen
Published: September 2018

Polystyrene waste was depolymerised by using various acidic and basic catalysts. Among the metal oxides, calcium oxide was found to be the cheapest and most effective catalyst for the depolymerization of waste polystyrene into styrene. Metal carbonates provided pure styrene, but in low yields. Acids were found to be poor catalysts for depolymerisation, since they led to further reactions leading to side products.
Properties of LDPE and Aluminum Composite from Recycled Long Life Packaging
Authors: Santa Marinha Ana Beatriz A , Pacheco Elen B.A.V. , Monteiro Elisabeth E.C.
Published: September 2018

This work evaluates the morphology, thermal, tensile strength and rheological properties of the composite of low-density polyethylene and aluminum (LDPEAl) obtained from recycled long-life packaging. The presence of aluminum in the composite was observed through morphological analysis. The mechanical tests showed that the aluminum presence (4% by weight) increased Young's modulus, but reduced the tensile strength and elongation at break. The rheological profile of the composite was not influenced by the aluminum presence at high shear rates compared with the pure LDPE. However, a small difference at low shear rates is presented.
Short-Time Glycolysis of Post-Consumer Pet Catalyzed by Different Metal Complexes
Authors: Prado Regis M.K. , Nascimento Christine R. , Azuma Chiaki , Dias Marcos L.
Published: September 2018

Oligomers of bis(2-hydroxyethyl terephthalate) (BHET) was obtained by glycolysis of PET applying a simplified method. PET glycolysis was carried out in presence of ethylene glycol (EG) at reflux temperature, PET:EG molar ratio of 1:3 and 0.1 wt.% of catalyst. Metal compounds based on acetates and acetylacetonates of Zn, Mn, Pb, Co, Cu and Sm were used as catalyst. Molecular weights (MW) of these oligomers were determined by size exclusion chromatography (SEC). Gaussian deconvolution of SEC curves used to evaluate the oligomers composition generated with each catalyst showed that reactions carried out in presence of zinc acetate, lead acetate and manganese acetylacetonate lead to oligomers with the lowest molecular weights, predominating monomer and dimer of BHET. DSC traces showed that the melting behavior of these oligomers are highly dependent on the MW composition and in all cases multimodal profiles with melting peaks ranging from 80 to 155 °C were obtained.
Biodegradable Low Density Polyethylene
Authors: Shah G.D.
Published: September 2018

LDPE in its unmodified form is not biodegradable. When it is compounded with additives or plasticizers, it is affected by microorganism in various degrees. Low Density Polyethylene film grade was compounded with butyl stearate, cottonseed oil, dioctyl phthalate, epoxidized soya bean oil, linseed oil, soya bean oil, groundnut oil and general-purpose polyester plasticizers. The amount of plasticizers was varied from 5–25% (w/w). The biodegradability was evaluated with respect to amount duration and type of plasticizer. The microbial susceptibility of various plasticizers was checked. Approximation of plasticizer concentration that exhibits highest susceptibility towards microbial attack was determined. The test method employed was screening of biodegradation of specimen under agitation.
Influence of Carbon Black on the Fuel Transport and Mechanical Characteristics of Natural Rubber/Acrylonitrile Butadiene Rubber Blends
Authors: Kumari Prajitha , Manoj K.C. , Unnikrishnan G.
Published: September 2018

Composites, based on natural rubber (NR), acrylonitrile butadiene rubber (NBR) and carbon black in different ratios, with three vulcanizing systems were prepared. Three types of carbon black viz. semi-reinforcing furnace (SRF), high abrasion furnace (HAF) and intermediate super abrasion furnace (ISAF) were used for reinforcement. The sorption studies were done in an atmosphere of petrol, kerosene and diesel. The effects of filler, blend composition, vulcanizing systems, penetrant size and temperature on the sorption characteristics were studied. The solvent uptake decreased with decrease in particle size of the fillers in the order: SRF > HAF > ISAF. The sorption studies were complemented by the examination of cure characteristics, mechanical and morphology. Mechanical properties such as stress-strain behaviour, tensile strength, and elongation at break have been found to be maximum for ISAF filled samples. The experimental results of mechanical and sorption tests have been compared with various theoretical models.
Studies on the Use of Cardanol as Plasticizer for Silica-Filled Nitrile Rubber
Authors: Alexander Mary , Abraham Beena T. , Thachil Eby Thomas
Published: September 2018

Cardanol is the main ingredient of cashew nut shell liquid (CNSL), an agro-byproduct. Its comparative merits for plasticizing silica-filled nitrile rubber (NBR) is the subject of this paper. Esters like dioctyl phthalate (DOP), polyesters, polyester ethers, polyester polyethers, etc are the conventional plasticizers employed for such compounding requirements. In this study, the mechanical properties, ageing behavior and torque time curves during cure of NBR plasticized by both these materials are compared under identical conditions. It has been established that cardanol when used as plasticizer, gives rise to similar mechanical properties, cure times and superior thermal stability in NBR vulcanizates.
Durability of Low-Heat, Ultra Rapid-Hardening, Latex-Modified Polymer Concrete
Authors: Won Jong-Pil , Kim Jeong-Hoon , Lee Si-Won , Park Chan-Gi
Published: September 2018

To address the shortfalls of existing varieties of ultra rapid-hardening cement, which is becoming more popular for resurfacing bridge deck overlays, we evaluated the effects of adding metakaoline and a latex polymer to such concrete. The modified cement showed excellent durability, based on its permeability characteristics and resistance to abrasion, repeated freezing and thawing, and scaling, and may prove an effective long-term solution for resurfacing bridge deck overlays.
Calophyllum Inophyllum Oil as Plasticizer in Natural Rubber Compounds
Authors: Raju P. , Nandanan V. , Kutty Sunil K.N.
Published: September 2018

Mechanical properties and the thermal degradation characteristics of natural rubber compounds with calophyllum inophyllum oil were compared to that of the control compound containing naphthenic oil. The compounds containing calophyllum inophyllum oil showed improved tensile strength, tear strength, modulus, compression set, abrasion resistance and resilience. Cure time was higher than the naphthenic oil mixes. Thermal studies showed an increase of 8 °C in the temperature of initiation of degradation and an increase of 6 °C in temperature at which the peak rate of degradation occurred. The peak rate of degradation was comparable to the control mix containing naphthenic oil.
Studies on the Optimisation of the Preparation Method and the Characterisation of Zinc Butyl Xanthate
Authors: Palaty S. , Devi P.V. , Honey J.
Published: September 2018

Zinc butyl xanthate (Zn(bxt)2) was prepared using both AR-grade and commercial-grade n-butyl alcohol (n-BuOH), potassium hydroxide (KOH), carbon disulphide (CS2), and zinc chloride (ZnCl2). The effect of the order of mixing of the reactants on the reaction time and the yield of Zn(bxt)2 was studied. The effect of the amount of ZnCl2 used for precipitation on the yield of Zn(bxt)2 was also investigated. The irritating smell of Zn(bxt)2 could be reduced considerably by using commercial-grade reagents. The yield of Zn(bxt)2 could be increased and the reaction time reduced. The maximum yield was obtained when 1 mol% ZnCl2 was used. The Zn(bxt)2 obtained was characterised by means of Fourier transform IR spectroscopy (FTIR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and proton magnetic resonance (1H NMR) spectroscopy.
Hybrid Composite Based on Nanosilica, Nylon 6 Short Fibre, and Styrene Butadiene Rubber – a Study on the Effect of Fillers and Bonding Agent
Authors: Mathew Leny , Kutty Sunil K.N.
Published: September 2018

Nanosilica was ssynthesized by acid hydrolysis of sodium silicate using dilute hydrochloric acid. The ssynthesized silica was scharacterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The particle size of silica was calculated to be 13 nm from XRD results. This synthetic nanosilica was used in place of hydrated silica in an HRH (hexamethylenetetramine, resorcinol, and silica) bonding system for a styrene–butadiene rubber (SBR)/nylon-6 short fibre composite. Nanosilica was also used as reinforcing filler in an SBR/nylon-6 short fibre hybrid composite. The cure characteristics and mechanical properties of the hybrid composites were evaluated. Minimum torque, maximum torque, and cure rate of the hybrid composites increased with silica loading. Cure time decreased with fibre loading and increased with silica content. Scorch time also decreased with fibre loading. The volume fraction of rubber in a solvent-swollen sample increased with nanosilica. Nanosilica in the rubber composites also improved the tensile strength, modulus, and tear strength to a greater extent than the conventional silica. Abrasion loss and hardness were also better for the nanosilica composites. Resilience and compression set were adversely affected. The composites showed anisotropy in mechanical properties.
Understanding the Regeneration of EPDM Rubber Crumbs from Used Tyres
Authors: Macsiniuc Adrian , Rochette Annie , Rodrigue Denis
Published: September 2018

In this work, EPDM rubber crumbs from used tyres have been treated in batch and continuous processes in order to produce a regenerated material. For this purpose, the effect of EPDM particle size, oil type, and concentration as well as processing time, temperature, and mixing intensity were controlled for treatment in an internal batch mixer and a twin-screw extruder. The degree of regeneration was quantified via a modification of the ASTM D6814 method based on crosslink density determination from swelling experiments. The results showed that crosslink density reduction can occur even without any addition of a chemical agent. It is also shown that some conditions can lead to an increase in crosslink density. Physical models are proposed to account for both increase and decrease in crosslink density with processing conditions.
The Effectiveness of Cardanol as Plasticiser, Activator, and Antioxidant for Natural Rubber Processing
Authors: Alexander M. , Thachil E.T.
Published: September 2018

Cardanol is the main ingredient of cashew nut shell liquid (CNSL), an agro-byproduct. The merits of cardanol as plasticiser, activator, and antioxidant for natural rubber processing are compared with those of a conventional plasticiser (aromatic oil), coactivator (stearic acid), and antioxidants (styrenated phenol (SP) and trimethyl quinoline (TQ)). The cure characteristics, mechanical properties, extractability, and ageing behaviour are compared under identical conditions. It has been established that cardanol, when used as plasticiser, coactivator, or antioxidant, gives rise among other things to similar tensile properties, shorter cure times, and superior ageing behaviour when compared with the conventional plasticiser, coactivator, and antioxidants. This is of significance from the viewpoint of economy and conservation.
Dynamic Mechanical Behaviour of an Elastomeric Hybrid Composite Based on Nanosilica and Short Nylon-6 Fibre
Authors: Mathew Leny , Narayanankutty Sunil K.
Published: September 2018

The dynamic mechanical analysis of short nylon-6 fibre/nanosilica-reinforced elastomeric hybrid composites was carried out over the frequency range 1–50 Hz at 70 °C. The storage modulus (E′) and loss modulus (E″) increased linearly with frequency for all the composites, irrespective of the matrix used. With the incorporation of short fibre, E′ improved uniformly over the frequency range studied. The storage modulus of the composite was greatly influenced by the incorporation of nanosilica for all the mixes. In the case of gum compound, E′ and E″ increased marginally up to 30 Hz, and beyond this the rate was high. The samples with higher fibre content showed a two-step increase in E′ and E″ with frequency. The rate of increase in E′ and E″ with silica for different samples showed that the rate was higher for samples containing nanosilica than for samples containing commercial silica. The E″ was also found to increase with increasing silica content.
Effect of Dopants and Preparation Conditions on the Conductivity of Polyaniline
Authors: Palaty S. , Mary K.J. , Honey J. , Devi P.V.
Published: September 2018

Aniline has been polymerised in the presence of inorganic acid dopants (HCl, H2SO4, HNO3, and HClO4) via chemical oxidative polymerisation at room temperature. The d.c. and a.c. conductivities were measured, and HClO4-doped polyaniline (PANI) was selected as the most conductive. The effect of morphology and particle size on conductivity was confirmed from SEM studies. To study the effect of preparation temperature on conductivity, PANI was prepared at different temperatures using HClO4 as dopant. The a.c. and d.c. conductivities were measured. SEM studies and X-ray analysis were carried out. PANI prepared at low temperature was found to be more conductive. The low-temperature-prepared PANI was dried at different temperatures, and conductivities were measured. Results reveal that PANI dried at high temperature shows higher conductivity. This is further confirmed by IR spectroscopy.
Injection Moulding and Metal Forming in One Process Step
Authors: Michaeli Walter , Maesing Roland
Published: September 2018

For high-class applications (e.g. automotive interior) metal decorated plastic parts impress the customers with a metallic look and cool-touch haptics. Producing these parts has been a highly complex process. The in-mould lamination process of metal sheets allows a shortened process chain. In the process the injected melt adheres to a primer system on the metal surface. Furthermore the pressurized melt causes a forming of the metal sheet. This new technology enables a one-step production of metal decorated plastic parts.

This paper describes design principles for metal (stainless steel and aluminum) decorated parts first. Then the effects of the injection molding process parameters on the forming quality are shown. An approach to simulate the forming process is presented and evaluated by test results.
Application of Organic Coatings to Titanium Dioxide Pigment and the Effect on the Processing and Properties of PVC
Authors: Lim B.C. , Thomas N.L. , Noble B.C.
Published: September 2018

This study investigates the effect of two different types of organic coating applied to titanium dioxide pigment on the processing and properties of rigid PVC. The first pigment was coated with polyol and siloxane, whereas the second pigment was coated just with polyol. The surface energies of the two coated pigments were determined by contact angle measurements. It was found that the pigment coated with both polyol and siloxane was more hydrophobic and gave better dispersion behaviour than the other pigment. The coated TiO2 pigments were dry blended in a calcium-zinc stabilised PVC window profile formulation and extruded on a laboratory-scale extruder. Fusion properties and impact strength were measured and there was found to be a small but significant improvement in these properties for the formulation containing the first pigment compared with that containing the second. Hence the improvements in processing and properties correlated with the hydrophobicity and dispersability of the two different pigments.
A Novel Reclaiming Agent for Ground Rubber Tyre (GRT). Part 1: Property Evaluation of Virgin Natural Rubber (NR)/Novel Reclaimed GRT Blend Compounds
Authors: Premachandra J.K. , Edirisinghe D.G. , De Silva M.I.A.
Published: September 2018

Use of reclaimed rubber as a component of a blend with virgin rubber or as a replacement for the virgin material in most rubber applications, especially in tyre components, has increased in the recent past. This is due to the increase in prices of natural and synthetic rubbers and growing concern about environmental issues. This research is aimed at evaluating the properties of rubber compounds produced by blending virgin natural rubber (NR) with ground rubber tyre (GRT), which was modified using a readily available, environmentally friendly, low-cost amino compound. Initially, reclaiming of 40 mesh GRT in the presence of rubber processing oil was studied at four different concentrations of the amino compound and two milling time periods. Mechanochemical reclaiming/devulcanisation was performed at a temperature of 30–70°C, using a laboratory two-roll mill. Properties such as initial plasticity, swelling ratio, crosslink density, and molecular weight between two crosslinks (Mc) of the reclaimed rubber samples were evaluated. Rubber compounds were prepared in the second stage by blending the reclaimed GRT samples with virgin NR in a ratio of 15:85. Mooney viscosity, initial plasticity, cure characteristics, and dynamic properties of the above blend compounds were evaluated and compared with those of the control compounds. This study shows that the amino compound acts as a devulcanising/reclaiming agent for GRT. Rubber compounds prepared by blending virgin NR with novel reclaimed rubber exhibit higher stock viscosity, lower scorch resistance, and lower hysteresis in comparison with the control compounds.
Gas-Assisted Compression Moulding of Glass Reinforced Polypropylene, Part 1: Scoping Study
Authors: Brzeski Ian
Published: September 2018

A new process of combining gas injection with compression moulding is presented. The process is called Gas Assisted Compression Moulding (or GasComp). The principle is based on the injection of nitrogen gas during a conventional compression moulding cycle. The flow of the material due to the compressive force of the press is assisted by the injection of gas into the centre of the molten material. The gas assists in the flow by coring out the material. An introduction to the process and moulding parameters are presented along with initial scoping studies using GMT, LFT and recycled GMT. Glass architecture was found to be a major factor in the shape and location of the gas cavity produced. This process is shown to be advantageous when compared to gas assisted injection moulding in that long fibre parts can be cored out.
Dye Sublimation - Variation of Dye Penetration Depths with Semi-Crystalline and Amorphous Polymers
Authors: Makenji Kylash
Published: September 2018

The dye sublimation process is used to decorate the surfaces of plastic, coated metal and ceramic components. Limited data is published on the performance of polymers under this process, and these findings show there are differences in the performance of amorphous and semi-crystalline polymers. The reason for these differences was investigated. Experimentation was conducted on a range of semi-crystalline and amorphous polymers. These were decorated using a standard cyan, magenta, yellow and black pattern. The level of dye penetration was measured using optical microscopy. It was found that the dye penetrated the semi-crystalline polymers approximately ten times more than in the amorphous polymers. There are disparities between the measured values here and previously published data. These disparities were found to exist as a result of large operating processing temperatures and times.
Modelling Cure Times for Thermoset-Thermoplastic Injection Moulding
Authors: Middleton B.
Published: September 2018

Thermoplastics and thermosets have very different temperature requirements which pose a problem when processing them together in multi-material parts. This paper examines the time available for the cure of a thermoset material in a thermoplastic injection moulding environment. It uses thermal equations to form a basic physical model of the temperature profile during the cooling stage within an injection moulding cycle. The model explores the different cooling times provided by using different thermoplastic substrates and the heat available from each of these to cure the thermoset component during a standard cycle. Thermal analysis of commercially available thermoset materials was undertaken and compared to the model results to determine if cure could be obtained in-mould. It was found that the properties and processing conditions of PA66 provided the greatest heat exposure to the thermoset material; it was also found that temperatures within the mould are high enough to initiate cure however only within the proximity of the thermoplastic – thermoset boundary. A result of this effect is to produce a novel in-to-out cure mechanism that produces a thermoplastic-thermoset-thermoplastic structure with the potential application as a barrier layer.
Opportunities for In-mould Painting at TVS Motor Company Ltd
Authors: Rajendren K.
Published: September 2018

TVS Motor Company is the third largest manufacturer of two-wheelers in India and one of the top ten manufacturers in the world. The company manufactures 1.5 million two-wheelers for both its domestic and overseas requirements. The company's manufacturing process involves painting of plastic, metal and aluminium components to enhance their appearance and performance properties. The company currently uses a conventional post painting process for its moulded plastic panels. However the conventional post painting process causes a huge impact on the environment through flue gas emissions from baking ovens, solvent emission from paint booths and ovens, sludge generation from paint booths and wastewater generation from paint booths and pre-treatment processes. The volumes of waste and cost for part attached to the painting process for TVS Motor Company are detailed in this paper. Paint shop replacement technologies in relation to current in-mould decoration technologies such as pigmented plastics, in-mould film, co-injection moulding and in-mould spray painting (INSPIRE) are considered. Based on current specifications and requirements for painted plastic components, INSPIRE is found to be the most advantageous paint shop replacement technology for current TVS Motor Company Ltd production as it uses a thermoset, matching current specifications. A design of experiments is performed using a polyester skin and ABS substrate to optimise part coverage for a sample part. Using statistical analysis spray time and spray pressure are found to be the most important process parameters for paint coverage. Paint coverage could be greatly improved compared to that which has been previously reported.
Use of Antioxidant-modified Precipitated Silica in Natural Rubber
Authors: Begum P.M. Sabura
Published: September 2018

Fillers play a dominant role in modifying the properties of the base polymer. Precipitated silica is a promising non-black filler for rubber vulcanisates. As silica is hydrophilic and rubber is hydrophobic, uniform dispersion of silica in rubber is difficult and gives rise to problems such as high initial viscosity. Silica has a number of hydroxyl groups, which result in filler–filler particle agglomeration and reagglomeration. Incorporation of silica into rubber is quite difficult compared with the incorporation of carbon black. The main aim of this study was to reduce the hydrophilicity of silica by coating antioxidant onto its surface, and hence achieve easy incorporation of silica into rubber. The preparation of antioxidant-modified precipitated silica and its use as filler in rubber compounds were investigated. The curing and mechanical properties of the compounds were compared with those of conventional compounds containing unmodified silica and antioxidant in the same dosage on natural rubber. The cure and mechanical properties were found to be superior for modified silica composites compared with unmodified silica composites.
Analysis for the heat transfer of fully tempered vacuum glazing based on the thermal resistance model and finite element model
Authors: Hu Dongfang , Li Yichen , Liu Chang , Li Yanbing
Published: September 2018

The fully tempered vacuum glazing, consisting of two fully tempered glass plates detached through a limited vacuum medium (below 0.01 Pa), is presented. The heat transfer through fully tempered vacuum glazing is complex, including heat conduction, thermal radiation, and convection. To analyze heat conduction through a stainless steel support ball, the thermal resistance of the support ball is established based on Hertzian contact model. And the total thermal resistance of the unit cell with one support ball is defined. The three-dimensional finite element model for a center unit cell of fully tempered vacuum glazing is simulated to validate the result of the total thermal resistance. The simulation transmission U-values are 0.26 W/m2 K. Meanwhile, the simulation transmission U-values of entire fully tempered vacuum glazing are 0.84 W/m2 K without frame insulation.