Multilayer nonwoven lining materials made of wool and cotton for clothing and footwear

Five types of multilayer nonwovens for clothing and footwear parts were obtained by the adhesive bonding method. The thickest middle layer of the material consists of evenly laid coarse camel or sheep fibers or of reconstituted cotton fibers from flaps, the upper and lower layers consist of knitwear, and polymer adhesive is located between the layers. The layers are bonded by thermal pressing at a temperature of 150 ± 5°C for 2.0 ± 0.2 min. The microstructure and morphology of fibers, polymer adhesive, and multilayer nonwoven fabric were investigated by FT-IR spectroscopy, SEM, and X-ray phase analysis. The chemical interaction between wool fibers and polymer adhesive, the geometric dimensions and shape of the fibers, the structure and morphology of the cross section of the layers of the material, and the change in the degree of crystallinity of the material have been established. The investigated coarse and thick fibers of camel and sheep wool are more suitable for the production of nonwoven textile material. In the process of thermal exposure, the molten polymer diffuses into the structure of the nonwoven layer and knitted fabric. The diffusion and excellent adhesion of the molten polymer to the fibers ensures the solidity and strength of the composite. The developed design provides high strength of the material as a whole and adhesive strength between layers, high heat-retaining properties, and the use of a mesh adhesive film provides sufficient air and vapor permeability.

3D-Printed Polymer-Infiltrated Ceramic Network with Biocompatible Adhesive to Potentiate Dental Implant Applications

The aim of this work was to prepare and characterize polymer–ceramic composite material for dental applications, which must resist fracture and wear under extreme forces. It must also be compatible with the hostile environment of the oral cavity. The most common restorative and biocompatible copolymer, 2,2-bis(p-(2′-2-hydroxy-3′-methacryloxypropoxy)phenyl)propane and triethyleneglycol dimethacrylate, was combined with 3D-printed yttria-stabilized tetragonal zirconia scaffolds with a 50% infill. The proper scaffold deposition and morphology of samples with 50% zirconia infill were studied by means of X-ray computed microtomography and scanning electron microscopy. Samples that were infiltrated with copolymer were observed under compression stress, and the structure’s failure was recorded using an Infrared Vic 2DTM camera, in comparison with empty scaffolds. The biocompatibility of the composite material was ascertained with an MG-63 cell viability assay. The microtomography proves the homogeneous distribution of pores throughout the whole sample, whereas the presence of the biocompatible copolymer among the ceramic filaments, referred to as a polymer-infiltrated ceramic network (PICN), results in a safety “damper”, preventing crack propagation and securing the desired material flexibility, as observed by an infrared camera in real time. The study represents a challenge for future dental implant applications, demonstrating that it is possible to combine the fast robocasting of ceramic paste and covalent bonding of polymer adhesive for hybrid material stabilization.

Pengaruh Asam Itakonat terhadap Properti Polimer Perekat Akrilik Berbasis Air

Acrylic-based polymer adhesive is a type of adhesive that can be used for pressure sensitive adhesive (PSA). Itaconic acid (IA) is a type of acid with 2 (two) OH groups which can form hydrogen bonds. The acrylic base can be used purely from its class. In some cases, however, the acrylic base can be used together with another base. Therefore acrylic-based adhesive with variable addition of itaconic acid was introduced in this study. In this application, the holding power property is one of the important parameters of a PSA. Therefore, holding power is the main parameter in this study. This research includes the preparation of tools and materials, mixing the main raw materials of acrylic monomer and itaconic acid with the types of surfactants and water, and product characterization. The polymerization process is carried out at a pressure of 1 atm with a temperature of 75°C - 80°C accompanied by stirring with a rotation rate of ± 500 rpm. The characterization of this research resulted in a PSA product with a holding power of 2 kg for 30 seconds to 620 minutes. While the resulting peel strength is 1.12 kgf / inc to 0.76 kgf / inc. Keywords: itaconic acid, acrylic PSA, holding power

Wetting characteristics of polymer adhesives with different chain bending stiffness

Polymer adhesives are widely used in daily applications and in industry owing to their flexibility and overall non-toxicity, particularly in interfacial adhesion. The spreading of polymer adhesives on adherend is one of the essential considerations for the interfacial adhesion of polymer adhesives, which is strongly related to their wetting behaviors. While relationships between polymer microstructure and adhesion have been investigated in previous studies, it remains challenging to unveil the effect of polymer microstructure on wettability. To address this issue, here we utilize coarse-grained molecular dynamics (CGMD) simulations to systematically elucidate how the wettability of a polymer adhesive droplet on a surface depends on bending stiffness. The wetting dynamics and the contact angle are studied to show the evolution of morphology of droplets during the wetting process. The results indicate the wettability is weakened by the increase of bending stiffness of polymer chain. Detailed thermodynamic property analysis is further conducted, revealing that the adhesion between the polymer droplet and substrate deteriorates due to the decline of wettability. Interestingly, we observe such deterioration becomes more significant by both increasing the temperature and decreasing the bending stiffness. Our study sheds light on the dependence of chain bending stiffness and temperature on the wetting behavior of polymer adhesive droplets, and offers insights, which, upon experimental validation can then be used for the design of adhesives or hydrogels.

Tailoring of Thermo-Mechanical Properties of Hybrid Composite-Metal Bonded Joints

Metallic substrates and polymer adhesive in composite-metal joints have a relatively large coefficient of thermal expansion (CTE) mismatch, which is a barrier in the growing market of electric vehicles and their battery structures. It is reported that adding carbon nanotubes (CNTs) to the adhesive reduces the CTE of the CNT-enhanced polymer adhesive multi-material system, and therefore when used in adhesively bonded joints it would, theoretically, result in low CTE mismatch in the joint system. The current article presents the influence of two specific mass ratios of CNTs on the CTE of the enhanced polymer. It was observed that the addition of 1.0 wt% and 2.68 wt% of multi-walled CNTs (MWCNTs) decreased the CTE of the polymer adhesive from 7.5×10−5 °C−1 (pristine level) to 5.87×10−5 °C−1 and 4.43×10−5 °C−1, respectively, by 22% and 41% reductions.