Significance of Adhesion Theories in Area of Flexible Bonded Structural Joints in Construction Sector

The issue of bonding has been a part of humanity throughout its history. The greatest development in this area occurred in the second half of the 20th century and the issue of bonding has gained a lot of interest from the scientific community. Over the past 80 years, there has been a significant increase in scientific research and grants aimed at defining adhesion. We now know that examining the adhesion of materials, determining the adhesive properties or simply evaluating the test results and assessing the failure of the test specimens is not possible without understanding the basic principles and theories of bonding, i.e. adhesive joining. The presented paper is focused on the description of fundamental adhesion theories and their usage in the field of structural bonding in construction industry. The importance of understanding to adhesive properties of used products is demonstrated on an example of four different surfaces in combination with representatives of high strength flexible adhesive systems intended for façade applications. Representatives with high surface polarity, medium-high polarity and low polarity were deliberately selected. The one-way ANOVA was performed to analyse the impact of surface adhesive properties on adhesion of bonded joints. It was confirmed that the riskiest is bonding of polymer-based materials. For all selected materials it was concluded that the hypotheses of the adsorption theory, which, to some extent, also includes the assumptions of other adhesive theories, seem to be the most fundamental for the presented researched area.

The impacts of sustainable inter-firm collaboration on business performance of shipping companies

PurposeTo gain competitive advantage, shipping companies need the abilities to manage environmental requirements, which this study refers to as sustainable shipping capabilities, including internal resources and external factors such as inter-firm collaboration. However, previous studies mainly focused on the effectiveness of internal resources, leading decision-makers in shipping companies to undervalue the significance of external relationships in managing sustainability issues and their impact on performance. Therefore, this paper aims to identify and examine the impacts of sustainable inter-firm collaboration on shipping companies' business performance (i.e. shippers' loyalty and financial performance).Design/methodology/approachA proposed model that explains the relationships between relation bonding strategies, sustainable inter-firm collaboration and business performance was developed. Accordingly, a survey questionnaire was constructed and sent to 294 shipping companies in Vietnam. Structural equation modeling was deployed to examine the validity of the measurement items and investigate relationships among the latent constructs.FindingsThe findings show that financial bonding strategies have the most significant impact on sustainable inter-firm collaboration, followed by social bonding strategies and structural bonding strategies. Furthermore, sustainable inter-firm collaboration has direct and indirect (via perceived shippers' loyalty) effects on business performance.Research limitations/implicationsRelational bonding strategies provide a unique perspective to sustainable inter-firm collaboration. This study also contributes to allocate external resources and capabilities to improve inter-firm collaboration, thereby maximizing financial performance.Originality/valueThis paper contributes to the literature by applying relational bonding strategies that determine the key factors enabling sustainable inter-firm collaboration.

Inspecting the properties of polypropylene/ poplar wood flour composites with microcrystalline cellulose and starch powder addition

Biocomposites composed of polypropylene (PP) poplar wood flour (WF) (0% and 20%), microcrystalline cellulose (MCC) (0%, 2%, and 6%), and starch powder (SP) (0%, 5%, and 10%) were examined. The mechanical, physical, biodegradability, and morphological properties were assessed. The mechanical properties, water absorption (WA), thickness swelling (TS), and biodegradability were improved by adding WF to PP. By increasing MCC and SP, the composite modulus of rupture (MOR), modulus of elasticity (MOE), tensile modulus, WA, TS, and biodegradability increased. The tensile strength increased by increasing MCC, while the opposite was true for SP. An increase in WA and TS of composite, would decrease static contact angle. The morphological studies indicated that by adding MCC and SP, the composite stress transfer and distribution ability and structural bonding of the composite improved. By increasing the biodegradability and reducing the sample weights, the extent of surface degradability increased.