SYNTHESIS OF A POLYETHYLENE-GRAFT-POLYSTYRENE COPOLYMER AND ITS COMPATIBILIZATION FOR LINEAR LOW-DENSITY POLYETHYLENE/POLY(PHENYLENE OXIDE) BLENDS

Based on unsteady diffusion kinetics, polyethylene(PE)-graft-polystyrene (PS) copolymers were designed and synthesized with a heterogeneous high yield titanium-based catalyst by copolymerization of ethylene with a PS-macromonomer using 1-hexene as a short chain agent to promote the incorporation of the PS-macromonomer. The presence of 1-hexene facilitated the diffusion of the PS-macromonomer, giving rise to the significantly increased incorporation of the PS-macromonomer. Compatibilization of blends of linear low density polyethylene (LLDPE)/poly(phenylene oxide) (PPO) with the PE-g-PS copolymer were investigated using scanning electron microscopy (SEM) and dynamic mechanical analysis (DMA).

Melt processing and properties of linear low density polyethylene-graphene nanoplatelet composites

Composites of Linear Low Density Polyethylene (LLDPE) and Graphene Nanoplatelets (GNPs) were processed using a twin screw extruder under different extrusion conditions. The effects of screw speed, feeder speed and GNP content on the electrical, thermal and mechanical properties of composites were investigated. The inclusion of GNPs in the matrix improved the thermal stability and conductivity by 2.7% and 43%, respectively. The electrical conductivity improved from 10−11 to 10−5 S/m at 150 rpm due to the high thermal stability of the GNPs and the formation of phonon and charge carrier networks in the polymer matrix. Higher extruder speeds result in a better distribution of the GNPs in the matrix and a significant increase in thermal stability and thermal conductivity. However, this effect is not significant for the electrical conductivity and tensile strength. The addition of GNPs increased the viscosity of the polymer, which will lead to higher processing power requirements. Increasing the extruder speed led to a reduction in viscosity, which is due to thermal degradation and/or chain scission. Thus, while high speeds result in better dispersions, the speed needs to be optimized to prevent detrimental impacts on the properties.

Production and Electrical Characterization of Low Density Polyethylene-based Micro- and Nano-dielectrics containing Graphene Oxide, Functionalized Graphene and Carbon Black additives

Oggigiorno la ricerca di nuovi materiali per gradatori di campo da impiegarsi in accessori di cavi ha iniziato a studiare alcuni materiali nano dielettrici con proprietà elettriche non lineari con la tensione ed aventi proprietà migliorate rispetto al materiale base. Per questo motivo in questo elaborato si sono studiati materiali nanostrutturati a base di polietilene a bassa densità (LDPE) contenenti nano polveri di grafene funzionalizzato (G*), ossido di grafene (GO) e carbon black (CB). Il primo obiettivo è stato quello di selezionare e ottimizzare i metodi di fabbricazione dei provini. La procedura di produzione è suddivisa in due parti. Nella prima parte è stata utilizzatala tecnica del ball-milling, mentre nella seconda un pressa termica (thermal pressing). Mediante la spettroscopia dielettrica a banda larga (BDS) si sono misurate le componenti reali e immaginarie della permettività e il modulo della conducibilità del materiale, in tensione alternata. Il miglioramento delle proprietà rispetto al provino di base composto dal solo polietilene si sono ottenute quando il quantitativo delle nanopolveri era maggiore. Le misure sono state effettuate sia a 3 V che a 1 kV. Attraverso misurazioni di termogravimetria (TGA) si è osservato l’aumento della resistenza termica di tutti i provini, soprattutto nel caso quando la % di nanopolveri è maggiore. Per i provini LDPE + 0.3 wt% GO e LDPE + 0.3 wt% G* si è misurata la resistenza alle scariche parziali attraverso la valutazione dell’erosione superficiale dei provini. Per il provino contenente G* è stato registrato una diminuzione del 22% del volume eroso, rispetto al materiale base, mentre per quello contenente GO non vi sono state variazioni significative. Infine si è ricercata la resistenza al breakdown di questi ultimi tre provini sopra citati. Per la caratterizzazione si è fatto uso della distribuzione di Weibull. Lo scale parameter α risulta aumentare solo per il provino LDPE + 0.3 wt% G*.

The role of land use and psycho-social factors in high density residents' work travel mode choices : implications for sustainable transport policy

Imperatives to improve the sustainability of cities often hinge upon plans to increase urban residential density to facilitate greater reliance on sustainable forms of transport and minimise car use. However there is ongoing debate about whether high residential density land use in isolation results in sustainable transport outcomes. Findings from surveys with residents of inner-urban high density dwellings in Brisbane, Australia, suggest that solo car travel accounts for the greatest modal share of typical work journeys and attitudes toward dwelling and neighbourhood transport-related features, residential sorting factors and socio-demographics, alongside land use such as public transport availability, are significantly associated with work travel mode choice. We discuss the implications of our findings for transport policy and management including encouraging relatively sustainable intermodal forms of transport for work journeys.

Meeting and greeting : activities in public outdoor spaces outside high-density urban residential communities

This paper examines the opportunities for social activities in public outdoor spaces associated with high-density residential living. This study surveyed activities in outdoor spaces outside three high-density residential communities in Brisbane. Results indicated that activity patterns in public outdoor space outside residential communities are different to general urban public outdoor space. This broadly but not fully supports current theories concerning activities in public space. That is some environmental factors have impacts on the level of social interaction. The relationship between outdoor space and a residential building may have a significant impact on the level of social activities. As a consequence, a new classification of activities in public space is suggested. In improving the level of social contact in public outdoor space outside a residential community, the challenge is how to encourage people to leave their comfortable homes and spend a short time in these public spaces. For residential buildings and public space to be treated as an integrated whole, the outdoor open spaces close to and surrounding these buildings must have a more welcoming design.

Case study 3. A subtropical urban community. Medium to high density residential typologies

Subtropical Urban Communities Project Urban design and residential buildings The Centre for Subtropical Design has researched design concepts for livable subtropical neighbourhoods characterised by higher-density, mixed-use, family oriented housing by conducting a design charrette and analysing the proposed designs to evaluate how well these typologies might support economic, environmental and social sustainability. http://www.subtropicaldesign.org.au/index.php?option=com_content&task=view&id=125&Itemid=163 The QUT Team produced designs (Case Study 3) within the research framework of the design charrette.

Conceptualising convenience : transportation practices and perceptions of inner-urban high density residents in Brisbane, Australia

High-density living in inner-urban areas has been promoted to encourage the use of more sustainable modes of travel to reduce greenhouse gas emissions. However, previous research presents mixed results on the relationship between living in proximity to transport systems and reduced car-dependency. This research examines inner-city residents’ transportation practices and perceptions, via 24 qualitative interviews with residents from high-density dwellings in inner-city Brisbane, Australia. Whilst participants consider public transport accessible and convenient, car use continues to be relied on for many journeys. Transportation choices are justified through complex definitions of convenience containing both utilitarian and psycho-social elements,with three key themes identified: time-efficiency, single versus multi-modal trips, and distance to and purpose of journey, as well as attitudinal, affective and symbolic elements related to transport mode use. Understanding conceptions of transport convenience held by different segments of the transport users market,alongside other factors strongly implicated in travel mode choice, can ensure targeted improvements in sustainable transport service levels and infrastructure as well as information service provision and behavioural change campaigns.

Project report. A subtropical urban community: Investigating medium to high density residential typologies by Design Charrette

The Centre for Subtropical Design at QUT, in partnership with the Queensland Government and Brisbane City Council, conducts research focused on 'best practice' outcomes for higher density urban living environments in the subtropics through the study of typical urban residential typologies, and urban design. The aim of the research is to inform and illustrate best practice subtropical design principles to policy makers and development industry professionals to stimulate climate-responsive outcomes. The Centre for Subtropical Design recently sought project-specific funding from the Queensland Department of Infrastructure and Planning (DIP) to investigate residential typologies for sustainable subtropical urban communities, based on transit orientated development principles and outcomes for areas around public transport nodes. A development site within the Fitzgibbon Urban Development Area, and close to a rail and bsu transport corridor, provided a case study location for this project. Four design-led multi-disciplinary creative teams participated in a Design Charrette and have produced concept drawings and propositions on a range of options, or prototypes. Analysis of selected prototypes has been undertaken to determine their environmental, economic and social performance. This Project Report discusses the scope of the project funded by DIP in terms of activities undertaken to date, and deliverables achieved. A subsequent Research Report will discuss the detailed findings of the analysis.

Research report. A subtropical urban community. Investigating medium to high density residential typologies. Findings and recommendations from the Design Charrette

In June 2009 the Centre for Subtropical Design at the Queensland University of Technology conducted a design charrette to research design concepts for liveable subtropical neighbourhoods characterised by higher-density, mixed-use, family orientated housing. Subsequent analysis of the proposed designs evaluated how well these typologies support economic, environmental and social sustainability. The study was led by Ms Rosemary Kennedy, Director of the Centre for Subtropical Design and QUT School of Design Adjunct Professor Peter Richards, Chair of the Centre for Subtropical Design Board and director of Deicke Richards Architects and Urban Designers.

A subtropical urban community. Investigating medium to high density residential typologies. Recommendations from the design charrette

In June 2009 the Centre for Subtropical Design at the Queensland University of Technology conducted a design charrette to research design concepts for liveable subtropical neighbourhoods characterised by higher-density, mixed-use, family orientated housing. Subsequent analysis of the proposed designs evaluated how well these typologies support economic, environmental and social sustainability. The study was led by Ms Rosemary Kennedy, Director of the Centre for Subtropical Design and QUT School of Design Adjunct Professor Peter Richards, Chair of the Centre for Subtropical Design Board and director of Deicke Richards Architects and Urban Designers.

Case study 1 : a subtropical urban community : investigating medium to high density residential typologies by design charrette

The public transport corridor bordering the study site runs NW to SE and is perceived as a source of noise and pollution. The key urban planning strategies adopted by this team were: • Acoustic separation from transport corridor noise source, • A regular grid pattern of urban blocks, and • A clear hierarchy of accessible open space throughout the development.

Report : Case study 2 : a subtropical urban community : investigating medium to high density residential typologies by design charrette

The case study site is physically disconnected from its surrounding community by the rail corridor and future bus lanes and is unlikely to be able to sustain its own commercial retail centre. As a result, it may also be socially disconnected from surrounding suburbs. However, it does offer proximity and access to an extensive „natural‟ area, and this is seen as key opportunity for the proposed development to develop a strong relationship with surrounding suburbs...

A subtropical urban community : medium to high density residential typologies - case study 4

On the case study site, using these strategies, the site density achieved was approximately 180 dwellings per hectare. According to ASK consulting engineers‟ acoustic report (in Ecolateral‟s report) the design gives solid consideration to the environmental noise issues associated with the site. The subject structure not only provides significant shielding of transport corridor noise to the suburb, it also minimises the potential for adverse impact on residential amenity within the building itself...