Use of water-based carbonyl-functional polymers on a cross-linker-free highperformance leather finish

The present paper aims to study a new high-performance coating formulation while avoiding the use of cross-linkers. By using acrylic polymers with carbonyl functional groups, the negative environmental effects of the finishing process can be minimized. These new polymers can give very good physical properties without losing the inherent properties of flexibility and elasticity needed in upholstery leatherPostprint (published version

Biopigment Tracing of Mangrove Rhizophora mucronate Leaf an Bark Waste and Its Application for Batik Dyeing by Multiple Fixations

The purpose of this research is to determine the pigments in the bark and leaves of mangrove (Rhizophora mucronata), to analyze rate of color fastness in batik, level of consumer interest, and most effective pricing for the resulting batik products. The research was conducted between June 2015 and February 2016, and took place in Mangunharjo village, Tugu district, Semarang city, Indonesia. The pigment identification tests were performed in Laboratorium Terpadu Universitas Diponegoro, Indonesia. This research focused on the leaves and barks of mangrove plants. The leaves and barks were extracted to be used as dyeing agents, after which the batik fabrics were fixated using alum, limestone and lotus. This descriptive research employed UV-Vis spectrophotometry to identify pigment and Adobe Photoshop computer program to perform color fastness analysis. The result showed that chlorophyll is a pigment which contributes to the color green in leaves. Photochemical test results also show that the pigment associated to the blackish-green hue was tannin, andthat which was associated with red was flavonoid and quinone. The various colors were applied in batik dyeing process, which resulted in a range of color from yellow to dark brown. Color fastness test of batik dyed with mangrove-derived pigments on wash air dry, wash press dry, and wash sun dry using calico as fabric showed that alum and limestone fixated fabric had the least color fastness, while conversely, lotus-fixated fabric displayed good color retention. Levels of consumer interest naturally-dyed batik fabric by alum fixation was 20%. Of all the respondents, 46.67% showed interest in limestone-fixated batik, whereas 40% responded well with the lotus-fixated batik. Consumer acceptance levels for the mangrove-dyed batik fixated by alum, limestone, and lotus were 6.67%, 16.66% and 13.33% respectively. High consumer interest in fabric fixated by limestone and lotus was attributed to darker and stronger hues. The most effective price point suggested per 2.1 x 1 m of fabric was between IDR 200,000 to IDR 350,000

Disk Accretion onto Magnetized Neutron Stars: The Inner Disk Radius and Fastness Parameter

It is well known that the accretion disk around a magnetized compact star can penetrate inside the magnetospheric boundary, so the magnetospheric radius \ro does not represent the true inner edge \rin of the disk; but controversies exist in the literature concerning the relation between \ro and \rin. In the model of Ghosh & Lamb, the width of the boundary layer is given by \delta=\ro-\rin\ll\ro, or \rin\simeq\ro, while Li & Wickramasinghe recently argued that \rin could be significantly smaller than \ro in the case of a slow rotator. Here we show that if the star is able to absorb the angular momentum of disk plasma at \ro, appropriate for binary X-ray pulsars, the inner disk radius can be constrained by 0.8\lsim \rin/\ro\lsim 1, and the star reaches spin equilibrium with a relatively large value of the fastness parameter ($\sim 0.7-0.95$). For accreting neutron stars in low-mass X-ray binaries (LMXBs), \ro is generally close to the stellar radius \rs so that the toroidal field cannot transfer the spin-up torque efficiently to the star. In this case the critical fastness parameter becomes smaller, but \rin is still near \ro.Comment: 7 pages, 2 figures, to appear in Ap

The Effects of Finish Type on Permeability and Organoleptic Properties of Python (Python Reticulatus) Skin Finished Leather

In the leather industry, there are many different types of finish, i.e. two-tone, transparent, semi aniline and opaque/solid color. The composition formulation of each finish type is different so each will impact not only on the performance but also on the properties of the finished leather. The objective of this research was to investigate the effects of finish type (natural, aniline, semi-aniline, and two-tone) on permeability and organoleptic properties of python skin finished leather. This research focused on the finishing process with various finish types. The results showed that the effect of semi-aniline (I,II) finish type on water vapor permeability reduction is the highest when compared with natural (I, II); aniline (I,II) and two-tone finish types. Otherwise, the effect of semi-aniline (I,II) finish type on organoleptic properties is the lowest compared with natural (I, II); aniline (I,II) and two-tone finish types. The aniline I finish type has better organoleptic properties

Development auxiliaries for dyeing polyester with disperse dyes at low temperatures

High-molecular weight organic compounds known as carriers are widely used to expedite polyester dyeing at atmospheric pressure at 100 °C. However, carriers are usually poorly biodegradable and can partially plasticize fibres. Also, dyeing at temperatures above 100 °C in the absence of a carrier entails using expensive equipment. In this work, we developed an alternative method for dyeing polyester at temperatures below 100 °C that reduces energy expenses, dispenses with the need to invest in new equipment and avoids the undesirable effects of non-biodegradable carriers. The method uses disperse dyes in a microemulsion containing a low proportion of a non-toxic organic solvent and either of two alternative development auxiliaries (coumarin and o-vanillin) that is prepared with the aid of ultrasoundPostprint (published version

The role of Hall diffusion in the magnetically threaded thin accretion discs

We study role of the Hall diffusion in the magnetic star-disc interaction. In a simplified steady state configuration, the total torque is calculated in terms of the fastness parameter and a new term because of the Hall diffusion. We show the total torque reduces as the Hall term becomes more significant. Also, the critical fastness parameter (at which the total torque is zero) reduces because of the Hall diffusion.Comment: Accepted for publication in Astrophysics and Space Scienc