Nonmetallic Printed Circuit Board Research Articles

The Development of Environmentally Sustainable Poly(vinyl chloride) Composite from Waste Non-Metallic Printed Circuit Board with Interfacial Agents.

The recycling of non-metallic printed circuit boards (NMPCB) as a filler in poly(vinyl chloride) (PVC) composite would help to encourage the use of waste NMPCB, thus, reducing some environmental concerns with regard to e-waste. The objective of this study was to comprehensively evaluate the effect of different interfacial agents, namely polypropylene grafted maleic anhydride (PP-g-MAH) and ϒ-aminopropyltriethoxy silane (ATPS) on the morphology and properties of PVC/NMPCB composites. A PVC/NMPCB composite was prepared by melt compounding with varying amounts of NMPCB ranging between 10, 20 and 30 wt.%. Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) analysis revealed the interactions between PVC and NMPCB when using both PP-g-MAH and ATPS interfacial agent. The properties and morphology of PVC/NMPCB composites were significantly dependent on the interfacial agent treated on the NMPCB surface. The phase morphology and mechanical properties of PVC/NMPCB composites (30 wt.% of NMPCB) were improved and the result also indicated that the higher compatibility of composites with ATPS as an interfacial agent led to our obtaining the maximum Young's modulus of 484 MPa. The dynamic mechanical analysis revealed the interaction at the interface, with the Tg shifting to a lower temperature in the presence of PP-g-MAH and strong interfacial adhesion noted with the improved Tg in the presence of the ATPS interfacial agent. Further evidence of the improved interaction was observed with the increment in density in the presence of ATPS when compared with PP-g-MAH in PVC/NMPCB composite. Hence, of the two interfacial agents, ATPS showed itself to be more effective when employed as an interfacial agent for NMPCB in PVC composite for industry.

Utilization of Waste Non-Metallic Printed Circuit Boards in Polymer Composites from Acrylate-Styrene-Acrylonitrile

One of the important environmental problems today is the increase in electronic and electrical wastes produced from daily usage and the modern lifestyle. This work focused on the use of waste non-metallic printed circuit boards (WNMPCB) obtained from comminuted recycled printed circuit boards (PCBs) as a filler for acrylate-styrene-acrylonitrile (ASA) composite. The effect of filler loading and the type of interfacial agent employed in the composite were investigated. The ASA/WNMPCB composites were prepared with varying amounts of WNMPCB as filler between 0-30 phr of ASA by melt-blending technique, and the ASA/WNMPCB composites would be modified with surface treatment agents, including a silane coupling agent and styrene-maleic anhydride (SMA). All materials were mixed by using a two-roll mill at 240 °C, and test specimens were prepared with an injection molding machine. Phase morphology, mechanical and thermal properties of acrylate-styrene-acrylonitrile (ASA) reinforced with waste non-metallic printed circuit boards (WNMPCB) were determined in this study and compared with neat ASA. Experimental results showed that WNMPCB could be employed as a filler, and improved properties were obtained. Phase morphology from SEM images was found that the interfacial modification enhanced the interfacial adhesion between WNMPCB (filler) and matrix (ASA), caused an improvement in properties. The maximum improvement of properties of ASA/WNMPCB was 30 phr of WNMPCB modified with styrene-maleic anhydride (SMA).

Comparison of Physical and Chemical Method for Removing Copper from NonMetallic Printed Circuit Board Scrap

Printed circuit boards (PCBs) are the basic components of electrical and electronic devices. E-waste management is challenging to implement due to accompanying difficulties and danger. Valuable metals and copper (Cu) are primarily recycled through various methods in the treatment of waste PCB. A large number of non-metals materials in PCBs are disposed of through combustion or in landfill, resulting in secondary pollution and resource waste. To reduce the amount of waste non-metallic PCB (NMPCB) and the influences toward environment, recent studies focused on the usage of NMPCB as filler to replace raw material. NMPCB as filler seems to have a good interaction with the raw materials and thus can enhance the strength of the newly formed product. In our study, we focused on developing new NMPCB added with waste NMPCB. Commercial NMPCBs are often a flat laminated composite comprising non-conductive substrate materials. Hence, pre-treatment methods to remove metals, especially Cu, must be investigated. The present study attempted to remove the Cu layer on PCB by using chemical and physical methods. The untreated and Cu removed PCB residues were characterized using X-ray diffraction (XRD), scanning electron microscopy, and infrared spectroscopy (FTIR) for the determination of structural and functional groups and hydrophobicity test. XRD analysis indicated that the Cu in untreated PCB was successfully removed using physical and chemical methods.

The effect of microwave pyrolysis on product characteristics and bromine migration for a non-metallic printed circuit board

At present, it is necessary to carry out environmentally friendly treatment of non-metallic fractions (NMFs) of waste printed circuit board (WPCB) to improve resource utilization. NMFs of WPCB are pyrolyzed by microwave heating to determine the effect of different operating conditions on the characteristics of pyrolysis products. The results show that yields for residue, oil and gas are 59.03–67.63, 7.10–28.46 and 4.86–33.88 wt%. A high temperature promotes a decrease in oil yield and an increase in non-condensable gas yield. An increase in the NaOH dose results in a more significant cracking of the oil to gas. Increasing the concentration of NaOH increases the mass fraction of the total Br in residues (from 23.62 to 86.94 %), so the addition of NaOH is beneficial to the fixation of Br. A kinetics study shows that there are two thermal decomposition regions (398–625 K and 675–925 K), and NaOH-catalyzed pyrolysis reduces the activation energy to 18.91 and 31.95 kJ mol−1, respectively. The formation of Br-containing substances in the pyrolysis oil and gas can be inhibited if the bromine fixation in pyrolysis residue increases. NaOH-catalyzed pyrolysis can reduce bromine and also reduce energy recovery efficiency. This pyrolysis process still requires further research to improve the recovery of energy and valuable materials.

The Effect of Microwave Pyrolysis on Product Characteristics and Bromine Migration for a Non-Metallic Printed Circuit Board

The Effect of Microwave Pyrolysis on Product Characteristics and Bromine Migration for a Non-Metallic Printed Circuit Board

Investigation of waste PCB leach residue as a reducing agent in smelting processes

The advancement in technology has resulted in the development of newer and improved electrical products. The older products are becoming obsolete and are discarded as waste at a continuously increasing trend. Printed circuit board (PCB) is the main focus of electronic waste recycling because of the inherently high value of contained metals such as gold and copper. Hydrometallurgical route, which is often used to recover the metals, does not take into account the non-metallic PCB fractions. These non-metallic fractions may end up in landfills or incinerated which leads to secondary pollution. In this work, the use of the leached PCB waste fraction as reductant in primary metal smelting operations and solid state reduction is investigated.Laboratory-scale experiments and thermodynamic modelling were performed to simulate solid state reduction of hematite (Fe2O3) using various blends of PCB and graphitic carbon. Differential Scanning Calorimeter (DSC) analysis of several samples were performed up to 1200 °C. Thermodynamic modelling was done using FactSage to predict the products of the hematite reduction below 1600 °C. The study showed that PCB residue might be used to partially replace the conventional reductants. The investigations revealed that at temperatures below 1000 °C, PCB reduces hematite to lower forms of iron oxide at a faster rate than that of graphite. The optimal blend contains about 20 wt% PCB residue which has the same reduction degree as graphite.Thermodynamic modelling of iron smelting was also performed using various blends of PCB and coal. The models showed that PCB residue might be used to partially replace the conventional reductants. The study revealed that in iron smelting, the optimal blend contains around 20 wt% PCB residue, with energy savings of 150 kWh/t of ore to achieve the same metal recovery.

Effect of particle size and amount of nonmetallic PCB materials on the mechanical properties of rHDPE/PCB composites

Composites based on recycled high density polyethylene (rHDPE) and nonmetallic printed circuit board (PCB) waste were made through melt compounding and compression molding. In this study, the chemical compositions of the nonmetallic PCB material were determined via XRF and it was confirmed that it contains predominantly 72.7% of glass fiber materials which improve the mechanical performances of the rHDPE matrix. The main aim of this study is to determine the effect of different particle sizes and loadings of nonmetallic PCB on mechanical properties of rHDPE/PCB composite. The results indicated that mechanical properties of composites were excellent when nonmetallic materials with particle size from 0.09 to 0.15 mm and adding amount was 30 wt%. Microscopic images revealed that nonmetallic particles with the size of 0.07-0.09 mm and 0.09 -0.15 mm contained majority of single glass fibers whereas, bigger particle sizes of 0.15-0.3 mm and 0.3-0.5 mm, contained glass fibers in the form of bundles and large resin sheet.

EFFECT OF WEATHERING ON THE PROPERTIES OF RECYCLED HIGH DENSITY POLYETHYLENE BASED NONMETALLIC PRINTED CIRCUIT BOARDS WASTE COMPOSITE

The weathering performances of nonmetallic printed circuit boards (PCB)-filled recycled high-density polyethylene (rHDPE) was investigated in this study. The compression molded rHDPE/PCB composite was exposed to both natural and accelerated weathering attacks. The durability of rHDPE/PCB composites was compared to neat unfilled rHDPE and virgin HDPE (vHDPE). When the exposure time increased, the color of rHDPE faded faster than vHDPE. The surface of composites with 30 and 50 wt% nonmetallic PCB flaked off after being exposed to both weathering conditions. Prolonged weathering exposure also caused loss of impact strength of all the samples with and without nonmetallic PCB filler. In general, composites with 30 and 50 wt% nonmetallic PCB is more resistible to weathering attacks as compared to unfilled rHDPE.

Synthesis of glass fiber-nano silicon carbide composite by using waste printed circuit boards and compact discs as resources

Abstract The rapid advances in technology, urbanisation and decrease in life span of electronic equipment have accelerated the generation of electronic waste significantly. Electronic waste is considered as serious social problem and environmental threat and hence sustainable methodology is critically required to recycle e-waste. In this paper, a novel approach to synthesise glass fiber-silicon carbide (SiC) composite by using waste printed circuit boards (PCBs) and compact discs (CDs) as resources is reported. The synthesis is based on carbothermal reduction using non-metallic PCB residue as glass fiber source, waste CD char as carbon source and silicon dioxide as silicon source. SEM, XRD, Raman and FTIR results confirm the formation of glass fiber-SiC composite and XRD signifies the major phases of β-SiC. SiC particles were mainly composed of sphere shaped nanoparticles and glass fiber sizes were in the range of 200–500 um length. This innovative approach of using electronic waste as resources could be an alternative for synthesis of glass fiber-SiC composite and also reduces the dependency on traditional raw materials.

Crystallization and thermal behavior of recycled polypropylene composites containing nonmetallic printed circuit board powder and β-nucleating agents

A recycled packaging material was found to be a PP copolymer after examinations with DSC, FTIR, and TG techniques. It produced 4.39% residue when heated to 800 °C. In addition, SEM microscopic observations revealed some particles dispersed in the recycled PP (recPP) matrix, resulting in a great source for promotion of recPP crystallization temperature. In the present work, NPG, TMB-5, and CaPA were used as β-nucleating agents to modify PP and recPP crystallization behaviors. The results imply that these three nucleating agents are effective for PP to form β crystal in which TMB-5 revealed the best induction and heterogeneous nucleation effects. However, the nucleating effect for NPG decreased when it was added to recPP. The effect of CaPA also weakened, whereas TMB-5 performed well with the optimum content of 0.1%. When CaPA was added together with PCB powder, the β-nucleating effect of CaPA was enhanced, making β crystal as the main form when using only 0.01% CaPA.

Sustainable composite panels from non-metallic waste printed circuit boards and automotive plastics

In this study, non-metallic waste from printed circuit boards (PCBs) and waste automotive plastics (WAP) were used to produce sustainable composite panels, with a wide range of potential uses comparable to products such as MDF (medium density fibreboard). The composite panels, made from differing proportions of non-metallic PCB waste and WAP, were fabricated by using a hot press. The physical properties of the fabricated panels were studied by density measurements. The panels were characterised mechanically through flexural, tensile and compression tests and fractured surfaces were observed using scanning electron microscopy (SEM) for interface interaction studies. The density of the produced panels increased linearly, as the proportion of non-metallic PCB waste increased, in a range of 0.956 g/cc for 100/0 (WAP/non-metallic PCB) to 1.227 g/cc for 60/40 (WAP/non-metallic PCB) panels. SEM images clearly show that the non-metallic glass fibres of the PCB waste were encapsulated by the plastics of the automotive waste. The homogeneous distribution and increase in interfacial adhesion between non-metallic glass fibres of the PCBs and WAP were observed. The results demonstrate that the addition of non-metallic PCB waste greatly improves the flexural, tensile and compression properties of composite panels, compared to 100% WAP panels. The flexural and tensile modulus of the 80/20 (WAP/non-metallic PCB) panel was, up by ∼50% and ∼280%, compared to 100% WAP. This sustainable and eco-friendly recycling approach provides an opportunity to utilise two problematic waste streams; complex non-metallic PCB waste and automotive plastics.

Degradation of organic pollutants by Ag, Cu and Sn doped waste non-metallic printed circuit boards

The disposal and reuse of waste printed circuit boards have been the major global concerns. Printed circuit boards, a form of Electronic waste (hereafter e-waste), have been chemically processed, doped with Ag+, Cu2+ and Sn2+, and used as visible light photocatalysts against the degradation of methylene blue and methyl violet. The elemental analyses of pristine and metal doped printed circuit board were obtained using energy dispersive X-ray fluorescence (EDXRF) spectra and inductively coupled plasma optical emission spectroscopy (ICP-OES). The morphology of parent and doped printed circuit board was obtained from scanning electron microscopy (SEM) measurements. The photocatalytic activity of parent and metal doped samples was carried out for the decomposition of organic pollutants, methylene blue and methyl violet, under visible light irradiation. Metal doped waste printed circuit boards (WPCBs) have shown higher photocatalytic activity against the degradation of methyl violet and methylene blue under visible light irradiation. Scavenger experiments were performed to identify the reactive intermediates responsible for the degradation of methylene blue and methyl violet. The reactive species responsible for the degradation of MV and MB were found to be holes and hydroxyl radicals. A possible mechanism of degradation of methylene blue and methyl violet is given. The stability and reusability of the catalysts are also investigated.

Activated carbon derived from non-metallic printed circuit board waste for supercapacitor application

Activated carbons (ACs) have been synthesized by using waste PCBs via physical activation subsequent to pyrolysis processes. The physical and chemical properties of the produced activated carbons were studied using nitrogen adsorption, FT-IR spectroscopy, RAMAN spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscopy techniques. Among the synthesized ACs, AC with the highest surface area of 700m2g−1 produced at 850°C for a time interval of 5h was subjected to electrochemical studies. Capacitance behaviour of the obtained AC sample has been evaluated using cyclic voltammetry (CV), galvanostatic charge–discharge (GC-D) measurements and electrochemical impedance spectroscopy (EIS) technique. Specific capacitance (Cspec) values vary from 220, 185 and 156Fg−1 for corresponding scan rate of 30, 50 and 100mVs−1 respectively. The well-developed surface area properties and good capacitance values associated with nitrogen functionalities indicates the AC developed is a good and suitable candidate for the supercapacitor fabrication.

Accelerated weathering properties of compatibilized composites made from recycled HDPE and nonmetallic printed circuit board waste

ABSTRACTThe main aim of this work is to examine the influence of the contents of nonmetallic printed circuit board (PCB) waste component on the photodegradation of recycled high‐density polyethylene (rHDPE) composites. The properties tested were chemical changes, flexural properties, color stability, water absorption, leaching properties, and crystallinity changes of the composites after exposure to 2,000 h of accelerated weathering. Surface degradation for composites with nonmetallic PCB was less compared to unfilled rHDPE mainly because glass fibers covered almost the whole surface of specimens, acting as a protective layer, thus, slowing down the photodegradation reaction. Incorporation of compatibilizer in rHDPE/PCB composites had played an important role in resisting degradation due to UV exposure. All the composite samples became lighter in the early stages of weathering exposure; however, compatibilized composites showed less lightening and reduction on strength and modulus. Carbonyl index increases with exposure time indicating that the oxidation reaction continuously occurred during the aging process. Incorporation of compatibilizer had successfully reduced the water absorption uptake by the composites and effectively delayed some degradation properties of weathering. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43110.

Encapsulation of nonmetallic fractions recovered from printed circuit boards waste with thermoplastic

The present work includes a process for encapsulation by combining substantially simultaneously dry nonmetallic printed circuit boards (PCBs) powder and recycled high-density polyethylene (rHDPE) in an extruder to form a homogenous matrix. The extruded materials were then molded into standard tensile, flexural, and impact properties testing specimens. Nonmetallic PCB mainly consists of large amount of glass fiber–reinforced epoxy resin materials. Incorporation of 50 wt% nonmetallic PCB in rHDPE matrix had increased the flexural strength and modulus by 35% and 130%, respectively. Tensile strength reported to be constant without much improvement. However, the Young’s modulus has increased by 180%, with incorporation of 50 wt% nonmetallic PCB. The addition of 6 phr (parts per hundred) maleated polyethylene (MAPE) resulted in 2-fold increase in tensile and flexural strength. Regarding the leaching properties, Cu was identified as the metal that leached at the highest level from the raw nonmetallic PCB, at 59.09 mg/L. However, after the nonmetallic PCB was filled in rHDPE/PCB composites, the concentration of Cu was reduced far below the regulatory limit, to only 3 mg/L. Thermal properties of composites were studied, and it was found out that incorporation of nonmetallic PCB fillers in rHDPE resulted in low thermal conductivity, whereas mechanical strength of the composites showed maximum improvements at 220 °C. Overall, the encapsulation technique using nonmetallic PCB waste has formed a monolithic waste form that provides a barrier to the dispersion of wastes into the environment.ImplicationsNonmetallic materials reclaimed from waste PCBs were used to analyze the chemical composition, and it was found that nonmetalllic PCBs mainly consist of glass fiber–reinforced epoxy resin materials. With such millions of glass fibers in nonmetallic PCBs, there are mass-excellent supporting bodies that enhance the mechanical properties of composites. In fact, utilization of nonmetallic PCB waste as filler in composites can dramatically restrain the solubility of heavy metals in leachate solution, thus making it safe to be used in practical products.

Utilization of Waste Non-Metallic Printed Circuit Board Fractions (NMPCB) as Aggregate to Create Green Concrete

In this research, to present a practical solution for disposal of Waste Non-metallic printed circuit board fractions (NMPCB), this material replaced 5, 10, 15 and 20% by weight of the coarse aggregate of control concrete. Results showed that consistency of fresh concrete decreased with increase in replace percentage. Bulk density of specimens falls by using (NMPCB), Compressive strength, static modulus of elasticity and flexural strength have decreased in specimens containing waste material. Durability properties, water absorption has increase, and Special electrical resistance has decrease in specimens containing (NMPCB). So, by notice to experimental results and environmental effect of (NMPCB), the best replacing percentage of (NMPCB) with coarse aggregate of control concrete is up to 10%.

Mechanical, thermal, morphological and leaching properties of nonmetallic printed circuit board waste in recycled HDPE composites

Abstract The nonmetallic powder recycled from waste printed circuit boards (PCBs) is used as a filler material in recycled HDPE (rHDPE) in production of rHDPE/PCB composites. This study aims to propose methods for reuse of waste nonmetallic PCBs in a more environmentally friendly way. Mechanical, morphological, thermal and leaching characteristic properties of compatibilized and uncompatibilized composites were assessed. A good balance between stiffness, strength and toughness was achieved for the system containing 30 wt% PCB. Thus, this system was chosen in order to investigate the effect of the compatibilizer on the mechanical properties of the composites. The results indicate that MAPE as a compatibilizer can effectively promote the interfacial adhesion between nonmetallic PCB and rHDPE. The addition of 6 phr MAPE increased the flexural strength, tensile strength and impact strength by 71%, 98% and 44% respectively compared to the uncompatibilized composites. While, overall thermal properties of the compatibilized and uncompatibilized rHDPE composites were low, which can be attributed to incorporation of nonmetallic PCB fillers in rHDPE possessing low thermal conductivity. In terms of environmental, after nonmetallic PCB was filled in rHDPE composites, the concentrations of Cu and Br in the leachates were far below the regulatory limits which are only 3.07 mg/L and 3.50 mg/L, respectively. So, it can be recommended that a balance in mechanical and thermal properties of composites without violating the environmental regulation was achieved with the incorporation of 30 wt% PCB and 6 phr MAPE compatibilizer.

Converting non-metallic printed circuit boards waste into a value added product.

The aim of this study was to investigate the feasibility of using nonmetallic printed circuit board (PCB) waste as filler in recycled HDPE (rHDPE) in production of rHDPE/PCB composites. Maleic anhydride modified linear low-density polyethylene (MAPE) was used as compatibilizer. In particular, the effects of nonmetallic PCB and MAPE on mechanical properties of the composites were assessed through tensile, flexural and impact testing. Scanning electron microscope (SEM) was used to study the dispersion of nonmetallic PCB and MAPE in the matrix. Nonmetallic PCB was blended with rHDPE from 0–30 wt% and prepared by counter-rotating twin screw extruder followed by molding into test samples via hot press for analysis. A good balance between stiffness, strength and toughness was achieved for the system containing 30 wt% PCB. Thus, this system was chosen in order to investigate the effect of the compatibilizer on the mechanical properties of the composites. The results indicate that MAPE as a compatiblizer can effectively promote the interfacial adhesion between nonmetallic PCB and rHDPE. The addition of 6 phr MAPE increased the flexural strength, tensile strength and impact strength by 71%, 98% and 44% respectively compared to the uncompatibilized composites.

PVC-based composite material containing recycled non-metallic printed circuit board (PCB) powders

The study is directed to the use of non-metallic powders obtained from comminuted recycled paper-based printed circuit boards (PCBs) as an additive to polyvinyl chloride (PVC) substrate. The physical properties of the non-metallic PCB (NMPCB) powders were measured, and the morphological, mechanical and thermal properties of the NMPCB/PVC composite material were investigated. The results show that recycled NMPCB powders, when added below a threshold, tended to increase the tensile strength and bending strength of PVC. When 20 wt% NMPCB powders (relative to the substrate PVC) of an average diameter of 0.08 mm were added, the composite tensile strength and bending strength reached 22.6 MPa and 39.83 MPa, respectively, representing 107.2% and 123.1% improvement over pure PVC. The elongation at break of the composite material reached 151.94% of that of pure PVC, while the Vicat softening temperature of the composite material did not increase significantly compared to the pure PVC. The above results suggest that paper-based NMPCB powders, when used at appropriate amounts, can be effective for toughening PVC. Thus, this study suggests a new route for reusing paper-based NMPCB, which may have a significant beneficial environmental impact.