Nanoscale surface roughening of mulberry silk by monochromatic VUV excimer lamp

Surface treatment of mulberry silk was carried out using a VUV excimer lamp (172 nm). The changes occurring in morphology and physical properties of silk were studied. The nanopores created on the surface of treated samples were quantitatively analyzed using a high resolution scanning electron microscope. The physical and chemical changes taking place in silk fabric on irradiation were studied through measurement of wetting and wicking time, weight loss, crystallinity, and strength. Effect of irradiation time and distance from the lamp on these properties was also studied. Results show that wettability and wickability of silk improved significantly on exposure before stabilizing at 5 min irradiation time while the weight loss continued to increase. The effect of irradiation was negligible when the distance of the sample from the lamp became >15 mm. The effect of irradiation on tensile strength was found to be insignificant. Presence of moisture in silk hindered the effect of irradiation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 4102–4106, 2007     

Printing flax/polyester blends—a new approach

Work at the University of Ulster has been carried out to investigate methods of achieving startling print colour effects. It has been realised that by arranging fibre blends and distribution, pleasing aesthetic results are made possible. In this article Brian Hill and George Gray give a brief account of their research.     

Study of unsaturated polyester and vinylester morphologies using excimer laser surface treatment

A technique based on the use of an ArF excimer laser (193 nm) to analyze the morphology of the unsaturated polyester and vinylester networks has been developed. This method is based on the use of the differences between the thresholds at which ablation of the various constituent phases of the materials occurs. After having determined the ablation threshold of a polystyrene, various surface treatments using excimer lasers fluence around this threshold were applied to unsaturated polyesters and vinylester. In the latter case, a two-phase structure consisting of microgels in a polystyrene phase was shown by scanning electron microscopy observations, allowing us to conclude that the mechanisms by which vinylester and unsaturated polyester networks are formed are similar. We also observed that the two-phase structure of the vinylester matrixes, unlike that of the unsaturated polyesters, is organized rather than random-structured, which could represent a major parameter contributing to the very good hydrolysis stability of these materials. In the event of degradation by osmotic mechanisms, the organized structure network would enable limiting of the development of the osmotic pressures by distributing the forces within the material, thus avoiding crazing. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 1703–1714, 1997     

Chemical grafting of curcumin at polyethylene terephthalate woven fabric surface using a prior surface activation with ultraviolet excimer lamp

Durable curcumin‐treated antibacterial polyethylene terephthalate (PET) fabrics (against Staphylococcus aureus) were produced by dyeing with curcumin after surface activation using vacuum ultraviolet excimer lamp at 172 nm. Surface change properties of the exposed fabrics were characterized by surface analysis methods such as wettability, atomic force microscopy, and X‐ray photoelectron spectroscopy. Results show an increase in surface hydrophilicity with a water contact angle of the PET fabric reaching 24° after 10 min excimer irradiation, which could be attributed to an increase in carboxyl group formation as confirmed by X‐ray photoelectron spectroscopy measurements. Varying concentrations of curcumin were immobilized onto untreated and vacuum ultraviolet‐irradiated PET samples using diffusion method at 90°C, and the treated fabrics characterized using K/S (color strength) values at 440 nm. K/S values increased when the PET surface was subjected to a prior excimer irradiation, because of grafting of curcumin at the PET surface. Increased excimer irradiation time increased grafting of curcumin because the inner fabric fiber surfaces were also more thoroughly treated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

The printing of polyester/cellulose blends-a new approach

This paper introduces a new dye system for the printing of polyester/cellulose blends. The new system is based on a combination of disperse dyes containing diester groups and reactive dyes containing a monochloro-s-triazinyl reactive group. By reference to published work on the reaction mechanism of monochloro-s-triazinyl reactive dyes with cellulose the development of a new approach to bring about reactive dye fixation in essentially neutral pH conditions is discussed. Practical application details of the new dye system are emphasised.     

灯箱布用涤纶工业丝纺丝工艺研究

利用正交试验和单因子试验,对影响灯箱布用涤纶工业丝的断裂强度和干热收缩率指标的工艺因素进行了研究。优化了灯箱布用工业丝的纺丝工艺,物理指标满足灯箱布使用要求。     

Afterclearing by ozonation: a novel approach for disperse dyeing of polyester

A set of trials has been conducted to examine the efficiency of ozonation afterclearing on poly(ethylene terephthalate) fibres dyed with disperse dyes. The afterclearing process was performed in neutral distilled water at room temperature with 12.8 ± 0.3 mg/min ozone at 400 ml/min ozone gas flow rate. The results indicate that 1 min ozonation time is adequate to achieve wash fastness results comparable with conventional reduction clearing without significant colour yield losses. Ozonation periods greater than 1 min not only caused significant colour yield losses, but also caused a severe decrease of the breaking load of the fabric. The advantages of ozonation afterclearing are: savings in energy and time, as it is performed at room temperature for only 1 min, and decrease of environmental load as it avoids the use of the harsh chemicals used in conventional reduction clearing.     

Compatibility and physical properties of a new polyester blend

The compatible nature of a new polyester blend, polybutylene-terephthalate (PBT) and a copolyester of bisphenol-A-neopentyl glycol-terephthalate (CP-350), has been inferred from the single T_g by DSC and dynamic mechanical studies. Compatibility is further confirmed from the progressive melting point depression of PBT, and the increasingly coarse and open spherulitic morphology of the blends as the weight percent of CP-350 increases. At and above 40 weight percent of CP-350, crystallization of PBT is impeded by the presence of high concentrations of CP-350 which results in a low degree of PBT crystallinity (0-8 percent) in such blends. The melt viscosity as a function of blend composition shows a good fit to the Hayashida model.     

Dyeing of woven polyester fabric with curcumin: effect of dye concentrations and surface pre‐activation using air atmospheric plasma and ultraviolet excimer treatment

Dyeing of polyester fabric with curcumin was studied at 90 and 130 °C without and with a prior surface activation of polyester fabric using two different ecotechnologies: air atmospheric plasma treatment and ultraviolet excimer lamp at 172 nm. Without surface activation, dyeing with curcumin followed classical disperse dye behaviour, with higher dye uptake at 130 °C than at 90 °C, and saturation was readily reached at 2% dye owf at 130 °C with a colour yield of 22. Surface‐sorbed curcumin molecules extracted with ethanol seemed to increase the colour yield values at 90 °C dyeing, while at 130 °C they decreased the colour yield values. When dyeing was carried out after a prior surface activation of the polyester fabrics, increased colour yield was observed at both dyeing temperatures for the ultraviolet excimer lamp only (with colour yield increasing from 2 to 10 at 90 °C and from 22 to 28 at 130 °C for a 2% dye owf). Indeed, both surface activation methods yielded hydrophilic species at the polyester fabric fibre surface, which were confirmed by water contact angle, X‐ray photoelectron spectroscopy measurements and atomic force microscopy. However, the surface of the polyester fabric activated using plasma lost all of its hydrophilic species, reaching the water contact angle of untreated polyester when subjected to the dyeing conditions. The excimer treatment yields hydrophilic species that are more resistant to high temperature and pressure dyeing.     

The quasi‐yarn‐dyed effect: triple dyeing of woven polyester/cationic dyeable polyester/viscose rayon blend fabrics by chemical treatments in the laboratory and on a pilot and an industrial scale

The aim of this study was to carry out triple dyeing of woven polyester/cationic dyeable polyester/viscose rayon blend fabrics with the required colour fastness and physical properties. The feel and final appearance of the fabric were achieved by partial removal of the viscose rayon moiety of the fabric through optimised causticisation treatments. The results of the triple dyeings obtained from laboratory and small‐scale experiments were successfully scaled up in authentic processing equipment. The final product, which has a yarn‐dyed effect, readily satisfied the requirements related to the colour fastness and physical properties.     

ESOA modified unsaturated polyester hybrid networks: A new perspective

Hybrid polymer networks based on unsaturated polyester (UPE) and epoxidized soybean oil acrylate (ESOA) were synthesized by reactive blending through free radical addition polymerization reaction. ESOA was prepared by acrylation of epoxidized soybean oil (ESO). The physical, mechanical, thermal and electrical properties of the cured blends were compared with the neat resin. ESOA resin bearing reactive functional groups showed good miscibility and compatibility with the UPE resin. The co‐cured resin showed substantial upgrading in the toughness, impact resistance, thermal properties, and downgrading brittleness up to the addition of 20 wt % of ESOA content. The muddled phase structure was corroborated by Fourier transform infrared spectroscopy, scanning electron microscope, and transmission electron microscopy and proved the formation of excellent hybrid polymer network. An improvement in overall properties has been achieved without seriously affecting any other properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44345.     

Cure kinetic study of organoclay‐unsaturated polyester resin nanocomposites by using advanced isoconversional approach

Curing behavior of an unsaturated polyester (UP) resin containing 3 wt % Cloisite 10A (UP/10A) and 3 wt % Cloisite 30B (UP/30B) catalyzed with methyl ethyl ketone peroxide (MEKP) as initiator and promoted by cobalt naphthenate as accelerator was investigated by dynamic differential scanning calorimetry (DSC) at heating rates of 2, 2.5, 3, and 3.5°C min⁻¹. X‐ray diffraction and transmission electron microscopy were utilized to evaluate the morphology of UP/10A and UP/30B nanocomposites. Kinetic parameters of cure reactions were evaluated using the advanced isoconversional method. The addition of nanoclay resulted in a decrease in the activation energy of the redox reaction compared to that of the neat UP resin. The pre‐exponential factor of the redox reaction for UP/10A and UP/30B was less than that of the neat UP. Results showed an increase in the concentration of styrene between Cloisite 10A platelets leading to a decrease in the intralayer styrene content. The high concentration of styrene between nanoclay layers may lead to the formation of polystyrene chains grafted on the alkyds chains. This homo‐polymerization was also observed in the variation of activation energy of UP/10A specimen versus the degree of conversion for 0.42 ≤ α ≤ 0.6 which is very close to the activation energy of free radical homo‐polymerization of styrene. POLYM. COMPOS., 34:1824–1831, 2013. © 2013 Society of Plastics Engineers     

A new two-stage curing system: Thiol-ene/epoxy homopolymerization using an allyl terminated hyperbranched polyester as reactive modifier

An allyl terminated hyperbranched polyester (HBP) was added to an epoxy formulation containing a trithiol compound to perform a thiol-ene click reaction. By this procedure a flexible thioether network was formed. The photoirradiation of the reactive mixture, which contained a cationic photoinitiator, converted the thioether network in a multifunctional thermal macroinitiator, capable to initiate the cure of the cycloaliphatic epoxy resin(CE) in a second thermal stage. Depending on the proportion of HBP, thermal or photocuring of the epoxy resin took place in different extent, leading to networks with different structures. The photocuring procedure was followed by FTIR and the thermal second stage by DSC. The materials obtained were characterized by DMTA, TGA and SEM. The addition of HBP-Allyl and the trithiol to the formulation allowed increasing the T_g on comparison with the neat epoxy thermoset. The system proposed constitutes a new two-stage dual photo-thermal curing procedure for cycloaliphatic epoxy resins with a thermal latent character.     

合成不饱和聚酯树脂的新型催化剂

介绍用自制催化剂合成通用型不饱和聚酯树脂的新工艺,克服了传统工艺的缺点,使反应速度加快,树脂质量提高,讨论了该催化剂存在下,工艺条件对反应的影响,给出了适宜的催化剂用量。     

Three-element mixed oxides: a new approach to basic catalysts

A series of three-element mixed oxides (IA)_x(IIA)_yAlO_z was prepared by sol–gel method, adopting a multivariate experimental design strategy in order to explore in a rational way the effects of preparation parameters on textural and basic properties. The textural properties were determined from N₂ adsorption/desorption isotherms, the basicity distribution by CO₂ chemisorption and temperature programmed desorption. Besides, the reactivity of toluene in the side-chain alkylation with methanol was taken as a measure of the acid–basic character of these oxides. The prepared three-element mixed oxides showed good basicity (>300 μmol/g) and textural properties among the mesoporous materials. Density and strength of the basic sites of the materials were related to the synthesis parameters by applying the multivariate analysis to data modelling. For example, the presence of large amount of alkali metals, IA/Al=0.30, was related to the increased density of medium-strong basic sites. The product distribution of the model reaction confirmed the presence of weak and very strong basic sites, the former responsible of aromatic ring alkylation and the latter of styrene synthesis.     

A new approach to batch process optimization using experimental design

Empirical and mechanistic experimental design methods are combined to construct partial models, which are, thus, used to design a process. The grid algorithm restricts the next experimental point to potential process optima, according to the confidence intervals around the optimal points, and works with any experimental design algorithm such as D‐optimal. Two case studies show the advantages of implementing the grid algorithm. On average the improvement due to the grid algorithm was 15–20% in the first case study. The second case study is based on thin film growth using four potential models, with the most probable model used for experimental design. The grid algorithm balances the trade‐off between two extremes: D‐optimal designs and sampling at the predicted optimal point. The methodology presented shows that the experimenter does not have to decide ahead of time on purely empirical or mechanistic experimental design methods, since both may be useful. © 2008 American Institute of Chemical Engineers AIChE J, 2009