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991.
A poly(imide benzoxazole) was prepared directly from trimellitic anhydride chloride and 2,2‐bis(3‐amino‐4‐hydroxyphenyl)hexafluoropropane (BisAPAF) monomers in a two‐step method. In the first step, a poly(hydroxyamide amic acid) precursor was synthesized by the low‐temperature solution polymerization in an organic solvent. Subsequently, thermal cyclodehydration of the poly(hydroxyamide amic acid) precursor at 350°C produced the corresponding poly(imide benzoxazole). The inherent viscosity of the precursor polymer was 0.22 dL/g. The cyclized poly(imide benzoxazole) showed a glass transition temperature (Tg) at 329°C and a 5% weight loss temperature at 530°C in nitrogen and at 525°C in air. The poly(imide benzoxazole) is amorphous as evidenced by the wide‐angle X‐ray diffraction measurement. The structures of the precursor polymer and the fully cyclized polymer were characterized by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance spectroscopy (1H NMR). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2388–2391, 2003  相似文献   
992.
With the population ageing in Taiwan, it is projected that elder care robots incorporating smart technologies will play an essential role in ambient assisted living. This research has two purposes: (1) to investigate whether older adults' colour-emotion associations and colour preferences for robot appearance affect their perceptual judgements; and (2) to explore gender differences in their judgements. Phase I of this research uses a questionnaire to investigate 91 participants' preferences for robot style and their emotional trigger words for the role of robots. Phase II experiments were performed on another 60 older adults to identify whether their colour-emotion associations and colour preferences affect their perceptual judgements. The research results show that, regardless of gender difference, participating older adults prefer a robot with non-human–like features. The results also show that there is no significant difference between males and females in terms of the effect of colour-emotion association on a robot's appearance. Older adults tend to associate warm colours with emotional semantics, such as friendly, comfortable, reassuring, gentle and lively. Preferred colours include red, white and yellow. Black and grey are almost never preferred by older adults. There are significant differences by gender in the preferences for the colours white and purple. Older females prefer purple more, while white is preferred by older males. For the other colours, there were no significant differences between males and females. Colour attributes do not have any effect on colour-emotion association, whereas colour preference is highly positively correlated with b*.  相似文献   
993.
In the early stage of a design process, it is important to create numerous and varied possible color plans for the target consumer group. These color plans help individual designers quickly find a few good color design schemes and give the design team ideas for brainstorming. The color plan of a product consists of the color combinations of its components and decorative patterns, which strongly influence the feelings of customers and thus their desire to purchase. However, very few studies have discussed these issues. In this study, a consultation and simulation system for product color planning that helps designers obtain the optimal color planning for components and decorative patterns of a product is proposed. This system includes two parts: one uses the interactive genetic algorithm to establish a creative evolutionary system that can interact with a designer to explore novel design schemes; the other extends the boundary extract algorithm to establish a color simulation system that can apply colors to the areas of product components and decorative patterns for color simulation. Finally, a case study of color planning for a motorcycle model is used to verify the feasibility of the proposed system. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 375–390, 2013  相似文献   
994.
Everyday millions of tons of eggshells are produced as biowaste around the world. Most of this waste is disposed of in landfills without any pretreatment. Eggshells in landfills produce odors and promote microbial growth as they biodegrade. The present invention provides an environmentally beneficial and cost-effective method of producing calcium phosphate bioceramics (hydroxyapatite or tricalcium phosphate) from eggshell waste. In this investigation, heat treatment produced solid state reactions between eggshell powders and dicalcium phosphate dihydrate (CaHPO4·2H2O, DCPD) or calcium pyrophosphate (Ca2P2O7). When eggshell powders (CaO) and DCPD were heat treated at 1150 °C for 3 h, only a single hydroxyapatite (HA) phase was found; no diffraction peaks of starting materials and no β-TCP were observed. The XRD patterns of the product fabricated from raw eggshell powders (CaCO3) and Ca2P2O7 heat treated at 1100 °C for 3 h showed that almost only pure β-TCP remained with a trace amount of HA. The calcium phosphate ceramic synthesized from eggshell powders contains several important trace elements such as Na, Mg and Sr.  相似文献   
995.
Chitosan with 45% deacetylation (CS45) grafted poly (acrylic acid) (CS45‐g‐PAA) was synthesized and characterized as an adsorbent of paraquat. CS45‐g‐PAA copolymers were prepared using H2O2(aq) as an initiator and NH4OH(aq) as a promoter. The highest grafting percentage of 44.2% was obtained using the traditional kinetic method. However, a maximum grafting percentage of 52.6% was calculated for the central composite design (CCD). Experimental results based on the reaction conditions that were predicted from the CCD are consistent with theoretical calculations. The grafted copolymer was characterized by FTIR, BET, and SEM. A representative CS45‐g‐PAA copolymer was hydrolyzed to a salt type (CS45‐g‐PANa) and used in the adsorption of paraquat. The adsorption equilibrium data correlate more closely with the Langmuir isotherm than with the Freundlich equation. The maximum adsorption capacity of CS45‐g‐PANa is 396.7 mg/g‐adsorbent. This value clearly exceeds that of Fuller's earth and the activated carbon which is the most commonly used binding agent for paraquat. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers  相似文献   
996.
Poly(methyl methacrylate) (PMMA) is known to be immiscible with poly(styrene) (PS) in the bulk state. Poly(ethyl methacrylate) (PEMA), poly(propyl methacrylate) (PPMA), and poly(n‐butyl methacrylate) (PBMA) are also known to be immiscible with PMMA (or PS). Therefore, PMAs (PMMA, PEMA, PPMA, and PBMA) are predicted by the mean field theory to be immiscible with poly(styrene‐b‐methyl methacrylate) (PS‐b‐PMMA) in the bulk state. However, the miscibility of PMAs with PS‐b‐PMMA may be different in the two‐dimensional state. Therefore, the mixed monolayer behavior of PMAs and PS‐b‐PMMA was investigated from the measurements of surface pressure‐area per molecule (π‐A) isotherms at three different temperatures (10°C, 25°C, and 40°C). Calculation of compressibility from isotherms provided the inflection data from maximum and minimum peaks. The miscibility and nonideality of the mixed monolayers were examined by calculating the excess area as a function of composition. Mostly, negative deviations from ideality were observed in the mixed monolayers. This is likely because of favorable interaction between PMMA and PMAs in the monolayer state. The positive deviations occurred at 40°C with PBMA at a high surface pressure. Therefore, with confinement in the two‐dimensional state, the miscibility between PMAs and PS‐b‐PMMA was greatly improved in comparison with the bulk state. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers  相似文献   
997.
Random or tapered solution styrene–butadiene copolymer (SSBR) is very difficult to prepare in an isothermal batch process without the use of polar modifiers because of the diverse reactivity ratios of the styrene and the butadiene in hydrocarbon solvents. In the presence of polar modifiers, the random SSBR can be synthesized by anionic living polymerization with the variety of microstructures, which results in the change of glass transition temperature (Tg). This article will discuss the use of sodium dodecylbenzene sulfonate as a polar modifier in isothermal batch process that controls the microstructure of the SSBR resulting in a random as well as tapered SSBR with low Tg (?67°C to ?80°C). The Tg of SSBR was controlled by the styrene content rather than the microstructure of polybutadiene. Physical properties of SSBR compounding were discussed for tire tread applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   
998.
This article describes an approach toward improving the characteristics of a photopolymer for holographic data storage application. The maximum diffraction efficiency (ηmax) and dynamic range (M#) of 9,10‐phenanthrenequinone (PQ)‐doped poly(methyl methacrylate; PMMA) both improved significantly after co‐doping with one of three nitroanilines—N,N‐dimethyl‐4‐nitroaniline (DMNA), N‐methyl‐4‐nitroaniline (MNA), and 4‐nitroaniline (pNA). In particular, the value of ηmax increased from 38% for the PMMA/PQ system to 72% for the PMMA/PQ/DMNA system (a 1.89‐fold improvement) and the value of M# increased accordingly from 2.7 to 7.3 (a 2.70‐fold improvement). Thus, the holographic data storage characteristics of PMMA/PQ photopolymers can be improved through co‐doping with nitroaniline compounds. We also investigated the mechanism of the nitroaniline‐induced improvement in optical storage performance using proton nuclear magnetic resonance and X‐ray photoelectron spectroscopy. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   
999.
In this study, we developed a foaming control system using the Gas Counter Pressure (GCP) combined with mold temperature control during the microcellular injection molding (MuCell) process and investigated its influence on the parts' surface quality and foams structures. The results revealed that under GCP control alone when GCP is greater than 10 MPa, part surface roughness for transparent polystyrene (PS) improved by 90%. When GCP increased, the skin thickness also increased, the weight reduction decreased and the average cell size reduced to about 30 μm. For black PS parts, when GCP is greater than 10 MPa, the part gloss reaches the same value as that molded by conventional injection molding. By increasing gas holding time, the cell density decreased and the cell size distribution became more uniform. The increase in amount of supercritical fluid foaming agent also increased the cell density. Applying mold temperature control alone with temperature in the range of 90–120°C (near Tg), the surface roughness improved by 65%. Increasing mold temperature decreased the skin thickness; however, the cell size distribution became significantly nonuniform. It was found that thin skin, small and uniform cell size as well as good surface quality can be achieved efficiently by simultaneous combining of GCP and mold temperature control. The proposed innovative approach may lead to a significant improvement and a more broad application for MuCell process. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   
1000.
Poly(lactic acid) (PLA) is a biodegradable aliphatic polyester, but its brittleness makes it unsuitable for many packaging and appliance applications. The goal of the work reported was to create novel poly(ester urethane)s that incorporate biodegradable poly(lactic acid) diols (PLA‐OHs) and good mechanical properties of increased molecular weight via crosslinked network formation for engineering plastics applications. Three kinds of polyols (PLA‐OHs, PLA‐OHs/poly(tetramethylene ether) glycol or PLA‐OHs/poly(butylene adipate) glycol (PBA)) and two kinds of diisocyanates (4,4‐diphenylmethane diisocyanate (MDI) or toluene 2,4‐diisocyanate (TDI)) were chosen for the soft and hard segments to compare their mechanical properties. In addition, 1,4‐butanediol and trimethylolpropane were each used as chain extender agents. Results showed the PLA/PBA‐polyurethanes (PLA/PBA‐PUs) of the MDI series and the PLA/PBA‐PUs of the TDI series had improved thermal stability and enhanced mechanical properties. Degradation behavior showed the PLA‐based polyurethanes could be degraded in phosphate‐buffered saline solution and enzyme solution. © 2012 Society of Chemical Industry  相似文献   
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