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Polyethylene terephthalate (PET)/nano-hydroxyapatite (nHAp) composite granules were obtained using twin-screw extruder. Preforms were prepared by injection molding and then PET/nHAp bottles were produced by blow molding. For PET bottles with nHAp, the migration amounts of carboxylic acid (COOH), acetaldehyde (AA), diethylene glycol (DEG), and isophthalic acid (IPA); glass transition temperature ([T.sub.g]); melting temperature ([T.sub.m]); and the maximum crystallization temperature ([T.sub.cry]) were measured. The load-carrying capacity, burst strength, stress cracking, and regional material distribution tests were carried out on the bottles. X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, and ultraviolet transmittance analyses were conducted to explain the changes in mechanical, chemical, physical properties, and light transmission of bottles. It was found out that the COOH amount increased and the AA content decreased with increasing nHAp amount. On the other hand, no change was observed in the amounts of DEG and IPA. Although the mechanical properties such as load-carrying capacity and burst strength of the bottles have improved, it has been determined that the standard environmental stress crack resistance test procedure cannot be applied to such a composite. Experimental findings indicate that nHAp disrupts the chemical structure of PET and it isolates harmful chemicals such as AA by forming intermolecular bonds. Moreover, with the addition of up to 0.8% nHAp, PET bottles block the light transmission approximately 80% within 400-700 nm wave length zone. The study demonstrates that the PET/nHAp composite bottles can be used in the food industry, particularly in the packaging of milk and milk products which are vulnerable to light exposure. KEYWORDS degradation, nano-hydroxyapatite (nHAp), packaging material, polyethylene terephthalate (PET), thermal and mechanical characteristics, UV transmittance, 1 | INTRODUCTION A wide variety of food packaging materials such as films, boxes, and bottles are widely used in all fields of life. Such packages of various types and [...]

This study presents the environmental impact of apparel consumption in Australia using life cycle assessment methodology according to ISO14040/14044:2006. Available published references, the Ecoinvent v3 dataset, the Australian life cycle assessment dataset and apparel country-wise import data with the breakdown of apparel type and fibre type were used in this study. The environmental impact assessment results of the functional unit were scaled up to the total apparel consumption. The impact results were also normalized on a per-capita/year basis. The Total Climate Change Potential (CCP) impact from apparel consumption of 2015 was estimated to be 16 607 028 tonnes CO2eq and 698.07 kg CO2eq/per capita-year. This study also assessed the impact of acidification potential (AP), water depletion (WD), abiotic resource depletion potential (ADP) - fossil fuel and agricultural land occupation (ALO) using the same methodology. The market volume of cotton apparel in Australia is 53.97 %, which accounts for 45 %, 96 %, 40 %, 46 % and 79 % of total CCP, WD, ADP, AP and ALO impact, respectively. Apparel broad categories of cotton shirt, cotton trouser, polyester shirt and polyester trouser have a high volume in the apparel market as well as a high environmental impact contribution. These high-volume apparel products can be included in the prioritization list to reduce environmental impact throughout the apparel supply chain. It was estimated that from 2010 to 2018 the per capita apparel consumption and corresponding impact increased by 24 %.

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The current study aimed to produce polyethylene terephthalate (PET)/takedaite (Ca3B2O6) composite bottles, an innovative packaging material with better performance. For this, Ca3B2O6 was firstly synthesized by sol–gel route and then it was incorporated to PET at five rates by extrusion. Finally, preform and PET bottles were produced by injection and stretch‐blow‐molding processes, respectively. The results showed that the use of Ca3B2O6 significantly improved the mechanical performance and UV transmittance of PET. Compared to pure PET, the load‐carrying capacity and burst strength enhanced by 133.66% and 54.16%, respectively. Environmental stress cracking (ESC) time increased from 0.3 to 18 min at 0.8% Ca3B2O6 concentration. Moreover, UV transmittance (~85%) of PET decreased to approximately ~18% in the visible region with the incorporation of 0.8 wt% Ca3B2O6. In terms of chemical degradation, Ca3B2O6 incorporation did not change the diethylene glycol (DEG) and isophthalic acid (IPA) rates, however it played an enhancing and reductive role in acetaldehyde (AA) and carboxylic acid (COOH) degradations, respectively. Accordingly, this novel product offers the opportunity to minimize the problems that may occur due to transportation/storage and photocatalytic degradation of food and beverages in PET packaging. [ABSTRACT FROM AUTHOR]

A commercial-scale reactive extrusion processing system for recycled poly(ethylene terephthalate) (PET) flakes with an added chain extender, pyromellitic dianhydride (PMDA), was investigated. The PMDA concentration was varied with the intention of reaching a higher recycled PET intrinsic viscosity ([[eta]]). The effect of changing the extruder residence time on the system's stability and the recycled PET [[eta]] was also investigated. Reactive extruded PET with a PMDA concentration up to 0.3 wt% was found to have a higher [[eta]] and lower carboxyl content than recycled PET processed in a normal extrusion system. A shift in [[eta]] of about 0.18 dl/g was obtained with a 0.3 wt% PMDA concentration. A PMDA concentration above 0.3 wt% produced chemical, thermal and hydrodynamic instability in the system, causing crosslinking reactions and gel formation. The reactive extrusion system was stable at low residence time (45 s) and moderate (0.15 wt%) PMDA concentration; however, using 0.2 wt% PMDA produced higher reactive extruded recycled PET [[eta]] with lower carboxyl content than other PMDA concentration levels examined. Residence times higher than 45 s produced higher reactive extruded recycled PET [[eta]]. Reactive extruded recycled PET was also tested for mechanical properties. Polym. Eng. Sci. 44:1579-1587, 2004. [c] 2004 Society of Plastics Engineers., INTRODUCTION Post-consumer PET undergoes a reduction in intrinsic viscosity, [[eta]], when recycled in a normal extrusion system. The occurrence of thermal and hydrolytic degradation reactions during recycled PET melt processing [...]

Graphene–polyamide‐6 composite (GC) filament with 9%·v/v graphene concentration was applied as feedstock in filament‐based material extrusion (ME) additive manufacturing. The materials are characterized by melt flow index (MFI), mechanical properties, dielectric properties, and electromagnetic interference shielding effectiveness (EMI SE) in the X‐band frequency range. Despite high graphene concentration, MFI is unaffected. In ME test specimens; GC has both superior elastic modulus and tensile strength at yield when compared with the neat polymer. Enhanced mechanical properties at high graphene concentration without diminished processability highlight the suitability of polyamide‐6 (PA6) as matrix material for graphene composite filaments. Scanning electron microscopy (SEM) imaging indicates graphene alignment in GC after printing. In both compression molded (CM) and ME test specimens, dielectric properties and EMI SE of PA6 are enhanced by graphene inclusion. Further analysis reveals that ME has a negative influence on absorption of electromagnetic waves, while reflection is virtually unaffected. [ABSTRACT FROM AUTHOR]