Flame retardant finishing of the polyester/cotton blend fabric using a cross‐linkable hydroxy‐functional organophosphorus oligomer

Blend fabrics of cotton and polyester are widely used in apparel, but high flammability becomes a major obstacle for applications of those fabrics in fire protective clothing. The objective of this research was to investigate the flame retardant finishing of a 50/50 polyester/cotton blend fabric. It was discovered previously that N,N′‐dimethyloldihydroxyethyleneurea (DMDHEU) was able to bond a hydroxy‐functional organophosphorus oligomer (HFPO) onto 50/50 nylon/cotton blend fabrics. In this research, the HFPO/DMDHEU system was applied to a 50/50 polyester/cotton twill fabric. The polyester/cotton fabric treated with 36% HFPO and 10% DMDHEU achieved char length of 165 mm after 20 laundering cycles. The laundering durability of the treated fabric was attributed to the formation of polymeric cross‐linked networks. The HFPO/DMDHEU system significantly reduced peak heat release rate (PHRR) of cotton on the treated polyester/cotton blend fabric, but its effects on polyester were marginal. HFPO/DMDHEU reduced PHRR of both nylon and cotton on the treated nylon/cotton fabric. It was also discovered that the nitrogen of DMDHEU was synergistic to enhance the flame retardant performance of HFPO on the polyester/cotton fabric.     

Conductivity and atmospheric aging studies of polypyrrole-coated cotton fabrics

Polypyrrole (PPy) is one of the preferred alternatives among the intrinsically conductive polymers (ICPs). In this study, PPy-coated cotton (PPy-CT) fabrics were synthesized by two step in situ chemical polymerization. The reaction parameters, such as monomer concentration and temperature, were studied in detail. The surface resistivity of PPy-CT fabrics ranged ∼ 15–5000 Ω⁻². To assess long-term usage potential, the atmospheric aging of conductivity characteristics of treated fabrics was monitored over a period of 6 months. It was found that the synthesis temperature had a significant impact on conductivity and atmospheric aging of PPy-CT fabrics. Furthermore, various sulfonic acid sodium salts added as external doping agents during polymerization also had a positive effect. The scanning electron microscopy revealed smoother morphology of sulfonic acid salt doped PPy coatings. The overall study addresses the durability aspect of PPy-CT fabrics in potential applications areas. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

An overview of empty fruit bunch from oil palm as feedstock for bio-oil production

Empty fruit bunch (EFB) from oil palm is one of the potential biomass to produce biofuels like bio-oil due to its abundant supply and favorable physicochemical characteristics. Confirming the assertion, this paper presents an overview of EFB as a feedstock for bio-oil production. The fundamental characteristics of EFB in terms of proximate analysis, ultimate analysis and chemical composition, as well as the recent advances in EFB conversion processes for bio-oil production like pyrolysis and solvolysis are outlined and discussed. A comparison of properties in terms of proximate analysis, ultimate analysis and fuel properties between the bio-oil from EFB and petroleum fuel oil is included. The major challenges and future prospects towards the utilization of EFB as a useful resource for bio-oil production are also addressed.     

EPS与棉花秸秆矿渣复合保温材料研究

在前期石膏、棉花秸秆纤维矿渣等墙体复合材料研究的基础上,通过掺加EPS颗粒研制出一种轻质、隔热、具有一定强度等多功能新型墙体复合材.该材料以EPS颗粒为保温骨料,矿渣为骨料,水泥、石膏为胶凝材料,通过掺加粉碎的棉花秸秆纤维来解决无机、有机材料界面的粘结强度低及EPS颗粒上浮的问题,从而试制出一种性能良好的墙体材料.     

Cellulose furoate. I. Synthesis in homogeneous and heterogeneous systems

Cellulose furoate was synthesized via heterogeneous and homogeneous reactions. Cotton cellulose and wood cellulose were used. Lithium chloride/dimethylacetamide solvent was used to dissolve the cellulose for the homogeneous reaction. The esterification reaction between cellulose and 2‐furoyl chloride was systematically studied. It revealed that the activation of cellulose was important for its esterification reaction. Activation by solvent exchange decreased the crystallinity and increased the accessibility of cellulose. X‐ray diffraction analysis showed no significant change in the spectrogram after activation of cellulose. The degree of substitution of cellulose furoate was influenced by the molecular weight of the cellulose, the stoichiometry of the reagents, the acid scavenger, and the reaction time. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2649–2655, 2001     

Structural change in mercerized cotton fibers on cellulase treatment

Cotton fibers treated with liquid ammonia and sodium hydroxide were hydrolyzed with crude cellulase. The structural change in the fibers due to the cellulase treatment was examined in relation to the apparent affinity of Congo Red. The cellulose III crystalline structure collapsed and generated intermediate‐molecular‐ordered regions on cellulase treatment. Adsorption of Congo Red occurred on the crystallite surfaces of cellulose II and cellulose III that was transformed from cellulose II. The fiber, the dominant crystallite phase of which was cellulose III that was transformed from cellulose II, had a considerably increased apparent affinity after cellulase treatment. The intermediate structure on the crystallite surface was associated with the adsorption of Congo Red in the cases of cellulose II and cellulose III. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1675–1680, 2001     

城市化背景下的城市表皮设计策略与国际实践

城市表皮不仅仅是可视的建筑立面,更是可接触的地表和可支持城市活动的场所。在全球快速城市化发展进程中,城市在全方位地日益改变。为更好地促进城市和谐发展,城市表皮设计的策略调整成为必然。本文通过对城市化背景下城市新特质的再认识和对城市表皮设计策略的再理解,总结提炼了对解决城市问题行之有效的城市表皮设计策略。并在此基础上,进一步分析比较了不同策略在国际实践中的应用情况,深入探讨了城市表皮设计策略的灵活性和多样性。     

棉纤维在NMMO溶液中的溶胀与溶解

用不同质量分数的N-甲基吗啉-N-氧化物(NMMO)溶液,在不同的温度和时间条件下,探究棉纤维的溶胀和溶解情况,并利用X射线衍射和红外光谱对纤维素溶胀前后的结构变化进行表征。结果表明:NMMO质量分数低于80%时,棉纤维只溶胀不溶解;在质量分数分别为83%、85%、87%的NMMO溶液中,棉纤维出现溶解现象;随着NMMO质量分数的增大、温度的升高、时间的延长,棉纤维的溶胀程度不断增加。在质量分数为83%的NMMO溶液中,棉纤维先溶胀后溶解;在质量分数为87%的NMMO溶液中,棉纤维不溶胀直接溶解;在质量分数为85%的NMMO溶液中,棉纤维的溶解存在先溶胀后溶解和直接溶解两种形式。质量分数为80%以下的NMMO水溶液处理后的棉纤维,结晶结构和化学结构均没有变化。     

Wet‐driven shape‐memory behaviors and thermal adaptability of cotton knitted fabrics containing crosslinked poly(ethylene glycol) moieties

Cotton knitted fabrics were treated with poly(ethylene glycol) (PEG) in the presence of polyhydric alcohol etherified dimethylol dihydroxy ethylene urea as the crosslinker and magnesium chloride hexahydrate as the catalyst. In wet–dry cycles, the fabrics treated with 30% PEG1500 in the presence of 15% crosslinker and 3% catalyst showed obvious wet‐driven shape‐memory behaviors in terms of a 12% shrinkage rate in the wet state and a 80% shrinkage‐recovery rate in the dry state. The results of weight gain, morphological structures, Fourier transform infrared spectra, and X‐ray diffraction pattern tests confirmed PEG deposits on the surface of the treated fabrics, demonstrated the crosslinking of cotton cellulose with PEG and crosslinker, and also explained the wet‐driven shape‐memory mechanism. The results from differential scanning calorimetry show that the treated fabrics with wet‐driven shape‐memory behaviors had a phase‐change enthalpy and heat‐storage capacity. The crosslinking of cotton cellulose with PEG had a strong influence on the mechanical performance and air permeability of the cotton knitted fabrics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43473.