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Vibriosis caused by Vibrio alginolyticus has severely affected the development of mariculture industry in recent decades. DctP, a tripartite ATP-independent periplasmic transporter solute-binding subunit, is thought to be one of the virulence factors in Vibrio. In this study, the results displayed no difference in morphological characteristics and growth between ΔdctP (dctP mutant strain) and WT (wild-type strain). Nevertheless, the ability of swarming motility, biofilm formation, ECPase formation, cell adhesion and colonized ability of ΔdctP significantly decreased compared to those of WT. The LD

The liquid components, such as plasticizer, in the charge of solid propellant can potentially migrate into the liner contacting with propellant gradually, causing negative effects on the energetic ...

This study investigates local residents’ attitudes toward shale gas exploitation in China through interviews of 730 residents of Sichuan Province and explores determinants of their support or oppos...

Growing attention has been paid to understanding public risk perceptions of shale gas development. This research has largely been conducted in the United States and Europe. Arguably, the environmental and social risks posed by drilling are potentially more severe in places like China, due to its geography and political system. However, little is known how those constantly exposed to risks (the “affected” public) evaluate these risks. In this study, in-depth interviews were conducted with local residents (n=25) in Weiyuan County, Sichuan Province, the region with the largest shale gas reserves in the country, to identify the perceived risks of the affected Chinese public and to explore underlying factors that impact risk perception. Our results suggest that affected Chinese residents were most concerned about groundwater contamination and air pollution above all other risks, and they tended to link risks to spatial proximity to shale gas wells. The multifaceted nature of perceived benefits played a novel and nuanced role in Chinese residents’ risk perception. Pride and disempowerment were found to attenuate the risk judgments of affected Chinese residents, which has not been observed in previous literature. Our findings provides policymakers with insight into how to improve risk communications to enhance understanding of affected publics, as well as to better design compensation schemes that may address inequities.

Hepatic hemangiomas are usually detected incidentally when investigating for other nonrelated pathologies. When symptomatic, they are usually large and cause symptoms such as abdominal discomfort or other digestive issues. Occasionally, uncommon presentations such as bleeding with coagulopathy (Kasabach-Merritt syndrome) or even fever of unknown origin may occur. As hepatic hemangiomas are benign, they do not result in tumor emboli and pulmonary thromboembolism due to hepatic hemangiomas is extremely rare. This is a case report of a rare case of a female with no known past medical history who presented with sudden death due to pulmonary thromboembolism, possibly as a result of an underlying giant hepatic hemangioma. Incidentally, she also had three other tumors-pancreatic cystic lymphangioma, cerebral capillary telangiectasia, and papillary thyroid carcinoma, and their potential contribution to the cause of death will be discussed.

This study examines an “evaluation nudge” in which consumers' preferences for tourism products are dependent on whether the online information about alternative products is presented jointly ( joint evaluation mode ) or separately ( separate evaluation mode ). Utilizing two studies, relationship between evaluation mode and information processing is examined first. Afterwards, the relationship between preferences and decision-making in the context of evaluating alternatives with positive and negative reviews is examined. Study 1 shows a classical preference reversal effect that consumers prefer a restaurant alternative that is superior in qualitative attribute in separate evaluation mode, while preferring the alternative that is superior in quantitative attribute in joint evaluation mode. Systematic information processing mode is found to mediate the impact of evaluation mode on preference for restaurant alternatives. Study 2 replicates findings of study 1 partially, and reveals the different impacts of evaluation mode on preference for hotel alternatives resulting from negative valence of customers’ reviews.

The purpose of this paper is to identify the key determinants of the information value of enterprises’ micro-blogs, drawing on the consumer’s perspective. This paper examines the effects of such information value on consumers’ purchase intention through the building of online brand equity. The paper also investigates how perceived usefulness intervenes in the relationship between micro-blog information value and consumer purchase intention.,The proposed research model is examined empirically using a survey of 315 users of the Sina micro-blog. The statistical analysis applies a method based on variance using partial least squares.,The results show that online retailers’ micro-blog posts, which are characterized by informativeness and persuasiveness as perceived by customers, positively impact online retailers’ brand equity, which in turn influences consumer purchase intention. In addition, perceived information usefulness is found to be an important contextual factor that moderates the relationship between perceived persuasiveness and online retailer brand equity.,This work adds significance to the literature by extending the research on micro-blog marketing and also provides practical recommendations for online retailers on the operation of micro-blogs.

Chinese domestic brands have developed rapidly in recent years, and yet few of them have entered global competition as product or service brands brands with exceptions such as Huawei. In addition, ...

The volume phase transition of a hydrogel initiated by shrinking may result in complex patterns on its surface. Based on this unique property of hydrogel, we have developed a novel solvent precipitation method to prepare a kind of novel superabsorbent polymers with excellent hemostatic properties. A porous carboxymethyl chitosan grafted poly (acrylic acid) (CMCTS-g-PAA) superabsorbent polymer was prepared by precipitating CMCTS-g-PAA hydrogel with ethanol. Its potential application in hemostatic wound dressing was investigated. The results indicate that the modified superabsorbent polymer is non-cytotoxic. It showed a high swelling capacity and better hemostatic performance in the treatments of hemorrhage model of ear artery, arteria cruralis and spleen of the New Zealand white rabbit than the unmodified polymer and other commonly used clinic wound dressings. The hemostatic mechanism of the porous CMCTS-g-PAA polymer was also discussed.

A series of promising and novel polyampholyte superabsorbent polymers (CMCTS-g-P(AA-co-LCADMAAC)) were prepared using carboxymethyl chitosan (CMCTS) as skeleton accompanied with graft copolymerization of acrylic acid (AA) and long-chain alkyl dimethyl allyl quaternary ammonium salts (LCADMAAC). The structure of LCADMAAC and prepared superabsorbent polymers were characterized. The optimal conditions for synthesizing polyampholyte polymers with the highest swelling ratio was identified by examining the equilibrium swelling ratio of the polymer prepared under different conditions. Moreover, the unique volume phase transition properties of these polyampholyte superabsorbent polymers were studied. The effects of pH, ionic strength and the ratio of alcohol/water mixture solution on the water absorbency of the polymers were determined.

This study examines the impact of culturally-derived power (i.e., personalized vs. socialized power) on the effectiveness of destination advertising via the moderation of arousal in advertising, by identifying regulatory focus as an underlying mechanism. The findings indicate that high-arousal tourism destination advertisement is more effective for individuals primed with personalized power; low-arousal advertisement is more effective for individuals primed with socialized power. Culturally-derived power is found related to regulatory focus, which interacts with arousal in advertising to influence destination advertising effectiveness. This work not only contributes to the tourism literature by providing a new cultural perspective to the investigation of power, but also informs destination marketers of the importance of designing tailored advertising messages for different tourists.

Shale gas development can negatively impact those residing in close proximity to projects. Evidence from protests in Europe and the United States suggests a growing prevalence of “NUMBYism” (Not Under My Backyard) sentiment. There is little public discourse about the public acceptance, particularly among those directly affected, of shale gas development in China. Moreover, little research has been done examining whether locally affected publics support or oppose shale gas development, putting policymakers at a disadvantage in terms of risk communication and effective energy governance. Through in-depth interviews with local residents (n = 25) in Weiyuan county that has the largest shale gas reserves in China, the present study extends prior literature on the “NUMBY” phenomenon by exploring local residents’ attitudes toward shale gas development, both locally and distantly. Here we find approximately 20% of our interviewees express views that are consistent with NUMBYism – oppose local development but support or are indifferent to development elsewhere. The rest express views that are fully supportive (52%) or opposed (8%) regardless of local or distant development, or indifferent to local development but either supportive or indifferent to development elsewhere (20%). We find interrelated factors such as national identity – not observed in previous studies – playing an important role in how residents view development. Moreover, drawing upon construal level theory, we also examine the role that different dimensions of psychological distance (e.g., social, temporal, uncertainty, and experiential) may play in explaining these views. These findings may inform policy design and risk communication about shale gas development in China.

A novel method to prepare the macrocyclic compound locating substitution derivatives of chitosan was investigated, by using cyclodextrin as the model of macrocyclic compound. The method combines the advantages of activated 6-OH of chitin and high efficiency of click reaction. Chitin C6-OHp-toluenesulfonate (CTN-6-OTs) was generated and subsequently transferred to chitin C6-N3via nucleophilic substitution. Afterwards,β-cyclodextrin was immobilized at 6-OH of chitin via click reaction to afford CTN-6-CD. Ultimately, CTS-6-CD was obtained by removing the acetyl group of chitin unit. The structures and properties of these products were characterized by FTIR, TG, and XRD, respectively. It was found that CTN-6-CD synthesized at the optimum conditions has an immobilized loading of1.6126×10-4 mol/g and that of the corresponding CTS-6-CD, generated by removal of the acetyl group, was1.6891×10-4 mol/g.

Magnetic nanoparticle-embedded polymeric micelles (MNP-PMs) prepared with amphipathic polymers are an important sustained-release carrier for hydrophobic drugs. The amphipathic chitosan derivatives (ACDs) based stimuli-responsive slow-release carriers have attracted considerable attentions because of the bioactivities and modifiability of chitosan. In the current study, a series of ACDs including alkylated N-(2-hydroxy) propyl-3-trimethyl ammonium chitosan chloride (alkyl-HTCC) and alkylated polyethylene glycol N-(2-hydroxy) propyl-3-trimethyl ammonium chitosan chloride (alkyl-PEG-HTCC) were prepared by the reductive amination of HTCC and PEG-HTCC, and their structures and properties were characterized. Octyl-HTCC/O-Fe3O4 and octyl-PEG-HTCC/O-Fe3O4 MNP-PMs were prepared by the hydrophobic interactions between the corresponding ACDs and oil soluble Fe3O4 magnetic nanoparticles (O-Fe3O4 MNPs), and characterized for the structure, magnetic performance and surface charge state. Their potential application as a drug delivery carrier was investigated upon the embedding efficiency and pH dependent sustained-release performance using the hydrophobic drug, paclitaxel (PTX), as a model drug. Our work has provided a new application strategy of ACDs in the multi-functional drug delivery carrier.

Prior studies of public behavioral responses to air pollution mostly treat respondents as a homogenous group, an assumption that limits our ability to design tailored messages to mobilize actions. This paper employs segmentation techniques to examine the heterogeneity of individuals’ adaptive and mitigation behaviors in response to air pollution. We administered a survey in Beijing and obtained a valid sample of 979 respondents. Using hierarchical cluster analysis, we identified three distinct segments of respondents: Activists (50.5%) who are most active in adaptation and mitigation; Mitigators (33.1%) who are fairly active in mitigation but inactive in adaptation; and Adaptors (16.4%) who are fairly active in adaptation but inactive in mitigation. They are distinguishable in terms of age, gender, education, smoking habits, and having respiratory diseases. Two important factors, i.e., risk perception and causal attribution, show different patterns in their influence on the different types of resonsive behaviors across the three segments. Risk perception is a positive predictor of adaptive behaviors and an insignificant predictor of mitigation behaviors; causal attribution has different influences on mitigation behaviors of the respondents in the different segments. Our study highlights the need to design tailored messages to motivate different segments of the population to adapt to and mitigate environmental risks.

Background: The National Cancer Institute (NCI) PREVENT Cancer Program (PREVENT) is a peer-reviewed R&D pipeline with the core emphasis on preclinical development and clinical translation of novel cancer preventive interventions. One of the latest PREVENT-supported projects include cGMP production and IND enabling studies of a broad spectrum experimental human papillomavirus (HPV) vaccine- HPV16 RG1-VLP. This monovalent chimeric virus-like particle (VLP) displays 360 copies of the highly conserved epitope RG1 (aa 17-36 of minor capsid protein HPV16 L2) in the DE loop of HPV16L1 VLP backbone, and is capable of eliciting broadly neutralizing antibodies that target several clinically relevant HPV genotypes. RG-1 induced cross-neutralizing titers are typically lower than anti-L1 antibodies generated by currently licensed HPV vaccines. Hence, durability of protection has been cited as a cause of concern. Here, using engineering-run cGMP grade HPV16-RG1VLPs formulated with alhdyrogel®, the durability of protection 6 month post-vaccination of HPV16 RG1-VLPs against Gardasil-9®, a licensed HPV vaccine was evaluated using an established papillomavirus disease model. Methods: New Zealand white rabbits (n=15 per treatment group) were administered three intra-muscular vaccinations of HPV16-RG1 (80 µg), human doses of Gardasil-9®, or no vaccine (adjuvant only). Following vaccination, in vivo protection was assessed against 8 high-risk oncogenic HPVs utilizing methods from an established cottontail rabbit papillomavirus (CRPV) disease model. Within each treatment group, 5 rabbits were challenged two weeks post-final vaccination (at peak serum ELISA titer), while another 5 were challenged six months post-final vaccination to assess durability of protection. The remainder 5 rabbits will be challenged one year post final vaccination. Results: During the peak-titer period, rabbits vaccinated with monovalent HPV16-RG1VLP were protected from disease development, which was comparable to the protection afforded by Gardasil-9®. Six months after final vaccination, despite lower serum titers, HPV16-RG1VLP immunized rabbits were still protected from disease development with vaccine efficacy comparable to that of Gardasil-9®. And, in some instances, HPV16-RG1VLP vaccine demonstrated a superior cross-protection. Conclusions: Even as a monovalent formulation, HPV16 RG1 VLP vaccination was able to provide comparable protection against a number of high-risk oncogenic HPV types, including types not covered by Gardasil-9®, even after six months post-vaccination. As a monovalent VLP, HPV16 RG1 VLP holds promise as a broad-spectrum preventative vaccine candidate that could potentially provide broader protection at lower production costs. Studies evaluating protection one-year-post vaccination is currently in progress. Citation Format: Jiafen Hu, Karla Balogh, Ken Matsui, Huimin Tan, Pola Olczak, George Buchman, Brian Howard, Jonathan White, Michelle Kennedy, Shizuko Sei, Elizabeth Glaze, Sarah Brendle, Christina Schellenbacher, Reinhard Kirnbauer, Richard Roden, Robert Shoemaker, Neil Christensen, Joshua Weiyuan Wang. A cGMP-grade chimeric papillomavirus candidate vaccine (HPV16 RG1-VLP) confers long term cross-protection compared to a nonavalent hpv vaccine in a pre-clinical papillomavirus animal model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-200.

The synthesis of chitosan 6-OH immobilized cyclodextrin (CTS-6-CD) via click chemistry was investigated. After protecting the 2-NH2 group of chitosan by forming a Schiff base (BCTS) with benzaldehyde, the protected chitosan C6-OH p-toluenesulfonate (BCTS-6-OTs) was generated by treating with p-toluenesulfonyl chloride. Afterwards, nucleophilic substitution of the sulfonate with NaN3 furnished the Schiff base protected chitosan C6-N3 (BCTS-6-N3). On the other hand, alkynylic β-cyclodextrin (CD-OPg) was obtained by alkynylation of β-cyclodextrin (β-CD). With these two substrates in hand, β-CD was immobilized at the Schiff base protected chitosan 6-OH position via click chemistry between CD-OPg and BCTS-6-N3 to afford BCTS-6-CD, and then chitosan 6-OH immobilized cyclodextrin derivates (CTS-6-CD) was obtained by deprotecting the Schiff base of BCTS-6-CD. The structures of these products were characterized by FTIR, and their crystal properties and thermal stabilities were studied by XRD and TG respectively. By using UV spectroscopy to determine the immobilized amount, we also investigated the effect of the click reaction conditions on the immobilized loading of the synthesized BCTS-6-CD. It was found that the immobilized loading was 197.61 µmol·g−1 in the BCTS-6-CD that was synthesized under the optimum conditions, and it went up to 223.17 µmol·g−1 in CTS-6-CD by deprotecting the Schiff base group.

In this study, we explored a new method for preparing C6 quaternary ammonium chitosan (CTS) derivatives. The C2NH2 of CTS was first protected by benzaldehyde. The C6OH of CTS was then transformed into a sulfonyl ester, which was then reacted with NaN3 through nucleophilic substitution to introduce the N3 group at the CTS C6 position. This intermediate was reacted in a click chemistry reaction with a terminal alkynyl quaternary ammonium salt; this was followed by the deprotection of C2NH2 with acid to furnish the C6 quaternary ammonium CTS derivative. The structures and properties of synthesized products in the reactions were characterized by Fourier transform infrared spectroscopy, NMR, X-ray diffraction, and thermogravimetric analysis, respectively. The effects of the reaction conditions on the degree of Schiff-base CTS quaternization were evaluated by elemental analysis. The largest inhibition zone test and the minimum inhibitory concentration test showed that compared with CTS, the prepared CTS derivative had significantly improved antibacterial activity toward Staphylococcus aureus and Escherichia coli. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

A novel method was developed for the preparation of chitosan derivative with a high substitution of cyclodextrins at 6-OH positions. Tosylated chitin at 6-OH positions (6-OTs-Chitin) was prepared and then displaced by a monoamino β-cyclodextrin derivative (Mono-[6-(2-aminoethyl)-amino-6-deoxy]-β-cyclodextrin, CDen) via nucleophilic substitution of the tosyl group to afford the 6-OH substituted cyclodextrin derivatives (Chitin-en-CD). Further removal of acetyl groups on the chitin main chain yielded the C6 substituted cyclodextrin derivatives (CTS-en-CD). The structures of the products were characterized by FTIR and their crystallinity properties were studied by XRD. The thermal stability of the product was studied by TGA. The optimal conditions for nucleophilic substitution of CDen to 6-OTs-Chitin were evaluated and the highest substitution capacity of Chitin-en-CD was found to be 93.97 μmol/g. Substitution capacity of the corresponding CTS-en-CD was 128.68 mol/g, which is much higher than the literature value. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Regulatory restrictions have increased in recent years on organisms produced using recombinant DNA and asexual gene transfer, a process commonly called genetic engineering or genetic modification. Regulatory agencies have raised special concerns and required additional scrutiny for perennial grasses and woody plants of interest for biofuels; these plants have incomplete domestication, invasive capabilities, and the ability to mate with wild or feral relatives. Regulations on these plants require extremely stringent containment through all phases of research and development, regardless of the source of the gene, the novelty of the trait, or the plants' anticipated economic or environmental benefits. We discuss the extent to which these requirements conflict with the realities of practical crop breeding, and prevent meaningful agronomic and environmental studies, thus hampering—and in most cases, precluding—the use of recombinant DNA breeding methods for perennial crop improvement. We propose regulatory ref...

Against the Cartagena Protocol and widespread scientific support for a case-by-case approach to regulation, the Convention on Biological Diversity has become a platform for imposing broad restrictions on research and development of all types of transgenic trees.

A novel superabsorbent polymer was prepared by graft copolymerization of sodium acrylate and 1-vinyl-2-pyrrolidone onto the chain of N,O-carboxymethyl chitosan. The molecular structure of the product was confirmed by FTIR. The surface morphologies before and after the polymerization were examined by SEM. By studying the water absorption of the polymer synthesized under different conditions, the optimal conditions for synthesizing the polymer with the highest swelling ratio was defined. We showed that the water absorption rates of the prepared polymers were high, the swelling processes of the polymers showed first-order kinetics, and the swelling ratio of the polymer was pH dependent.

Trimethylsilyl hydroxypropyl cellulose (TMS-HPC) was synthesized from hydroxypropyl cellulose and hexamethyldisilazane in dimethyl formamide. The structure of TMS-HPC was characterized by infrared spectroscopy, 1H NMR and 13C NMR. The obtained TMS-HPC achieved solubility in a variety of organic solvents, such as chloroform, acetone, and xylene so that the lyotropic liquid crystal mesophase can be formed in concentrated acetone. The critical concentration (C∗) in acetone confirmed by PLM photographs is approximately 36%. The relationship between the structure and solubility was analyzed using XRD. With the partial protection technique of the hydroxyl group via the TMS group and the solubility of TMS-HPC in organic solvents and the easy deprotection of TMS groups, a new amphiphilic biodegradable graft poly(e-caprolactone) (PCL) with water-soluble HPC as a backbone was obtained by homogeneous graft copolymerization. The structure of the graft copolymer (HPC-g-PCL) obtained was confirmed by 1H NMR.

Microporous cellulose membranes were prepared from novel cellulose/aqueous sodium hydroxide solutions by coagulation with aqueous H2SO4 solutions. The free and glass-contacting surface morphology of the microporous cellulose membranes showed an asymmetric porous structure. The morphological structure, tensile properties, and permeability of the microporous cellulose membranes could be controlled by changes in the coagulation conditions such as the coagulant concentration and the coagulation time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 920–926, 2006

Different cellulosic materials were treated with different extraceller microbial enzymes. Changes in structure and properties of the cellulose caused by enzymatic treatment depend on the composition, the type of enzyme and the type of cellulosic materials. Both endoglucanase and crude cellulase have pronounced effects on the structure of cellulose. The variation of crystal structure was found to attack preferentially the (0 0 2) crystal planes for cellulose I during enzymatic hydrolysis.

The nonisothermal crystallization process has been investigated by Fourier transform infrared (FTIR) micro-spectroscopy for the 40/60 wt % blends of metallocene linear low density polyethylene (m-LLDPE) and ethylene/vinyl acetate copolymer (EVA) at the molecular level. In the cooling process, thermal spectra of mLLDPE/EVA blends were collected between 150°C and 67°C at 1°C interval. According to the van't Hoff equation at constant pressure, the changes of absorbance ratio corresponding to high and low vibrational states were calculated; hereby, apparent enthalpy differences of vibration energy states transformation (▵Hv) of characteristic groups could be obtained. Combining with DSC analysis, two exothermal peaks were examined in the crystallization process, corresponding to mLLDPE-rich and EVA-rich domains, respectively; while in comparison of the ▵Hv values of various characteristic groups corresponding to the two exothermal peaks, the bending vibrational mode of methylene groups has been found to make a prominent contribution to the movement and regular arrangement of mLLDPE and EVA chain segments towards each rich domain in the crystallizing process. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 261–267, 2005

Different cellulosic materials were treated with different extraceller microbial enzymes. Changes in structure and properties of the cellulose caused by enzymatic treatment depend on the composition, the type of enzyme and the type of cellulosic materials. Both endoglucanase and crude cellulase have pronounced effects on the degree of polymerization and the structure of cellulose. The variation of supramolecular structure was found to wide variations in conformation caused by the change of the hydrogen bonding energy.

In an attempt to elucidate the effect of mixing in high‐shear regimens on the extent of enzymatic hydrolysis of cellulosic substrates, cellulose was hydrolyzed using a commercial cellulase preparation at various enzyme concentrations and by three agitation regimens. The activity of cellulase decreased with increasing agitation rate and elapsed mixing time. The effect of shear on enzyme denaturation decreased with increasing enzyme concentration.

The relation between burning rate and pressure was obtained for the monopropellant HNIW with some metal oxides and organometallic salts added. It was found that PbO, Fe 2 O 3 , CuO, etc. did not decrease the exponent for the dependence of burning rate on pressure; but some organometallic salts did. The combustion characteristics of HTPB/HNIW composite solid propellants were also studied. Photographs of the flame structure of HNIW propellants were taken. The thermal decomposition of these propellants with organometallic salts added were studied using DSC and in situ FTIR. Some additives inhibit the thermal decomposition of HNIW.

PEO-b-PBA [PEO: poly(ethylene oxide); PBA: poly(butyl acrylate)], an amphiphilic block copolymer, prepared by redox radical polymerization, was characterized by infrared and 1H nuclear magnetic resonance spectroscopy. The result revealed the existence of PEO and PBA segment in purified block copolymer. The thermal behavior of the block copolymer was determined by differential scanning calorimetry. With the introduction of PBA noncrystalline segment, the crystallinity of PEO was decreased. The emulsifying and water absorptive properties of PEO-b-PBA were also examined. It was found that the emulsifying volume and type were dependent on the amount of block copolymer and the PEO content in block copolymer. Under a certain range, the emulsifying volume increases with an increase of PEO content. The more the PEO content in block copolymer, the stronger the water absorptivity was. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3432–3436, 2003

Novel thermoplastic polyurethane (TPU) elastomers based on copolyether (tetrahydrofuran ethylene oxide) as soft segments, isophorone diisocyanate and 1,4-butanediol as hard segments were synthesized for the purpose of using as propellant binders. In order to increase the miscibility of thermoplastic polyurethane elastomers with nitrate ester, polyethylene glycol (PEG) is incorporated in the co-polyether (tetrahydrofuran ethylene oxide) as soft segment. When the molecular weight and content of polyethylene glycol are controlled to 4000 and 6% of soft segments, respectively, the properties of thermoplastic polyurethane elastomers are most perfect. If plasticizing ratio of nitrate ester to thermoplastic polyurethane elastomers exceeds 4 no crystallinities are determined at room temperature. The propellant samples were prepared by a conventional absorption-rolling extrusion process and the mechanical and combustion properties evaluated afterwards. The maximum impulse reaches up to 265∼270 s which is a little bit higher than that of a HTPB propellant. The measured results reveal a promising TPE propellant candidate which shows good processing temperature (

Two commercial polymer materials, metallocene linear low density polyethylene (m-LLDPE) and ethylene/vinyl acetate copolymer (EVA) have been used to form binary blends of various compositions. The mechanical properties, morphology, rheological behavior, dynamic mechanical properties, and crystallization of m-LLDPE/EVA blends were investigated. It was found that with the addition of EVA, the fluidity and processability of m-LLDPE were significantly improved, and the introduction of polar groups in this system showed no significant changes in mechanical properties at lower EVA content. As verified by morphology observation and differential scanning calorimetry analysis, miscible blends were formed within certain weight ratios. Dynamic mechanical property studies showed that flexibility of the blends was enhanced in comparion with pure m-LLDPE, where the peak value of loss modulus shifted to lower temperature and its intensity was enhanced as EVA content increased, indicating the existence of more amorphous regions in the blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 905–910, 2004

After the protection of partial hydroxyl groups with trimethylsilyl (TMS) groups, hydroxypropyl cellulose becomes soluble in organic solvents, and the number of hydroxyl groups as initiating groups can be controlled. As a result, a new brushlike graft poly(ϵ-caprolactone) can be prepared with hydroxypropyl cellulose as the backbone polymer by homogeneous ring-opening graft polymerization and deprotection. The protection and deprotection of the TMS group during the entire procedure were carefully monitored with Fourier transform infrared (FTIR) and NMR, and the final graft copolymers were characterized with FTIR, 1H NMR, 13C NMR, gel permeation chromatography, and differential scanning calorimetry. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 273–280, 2003

A water-swellable rubber (WSR), compatibilized by the amphiphilic block copolymer, has been prepared by blending a natural rubber (NR) matrix with crosslinked sodium polyacrylate (CSP), poly(ethylene oxide)-b-poly(butyl acrylate) (PEO-b-PBA), poly(ethylene glycol) (PEG), reinforced filler, and vulcanizing agents. The preparation process was described. The microphase structure of WSR was characterized by a scanning electron microscopy (SEM) photograph. The dependence of the degree of the water-absorbing and the water-swelling, the water-absorbing and water-swelling rates on CSP, PEG, and PEO-b-PBA contents were investigated. The compatibilizing mechanism of PEO-b-PBA on WSR was studied. And the optimum composition range was identified: CSP (30–60 phr), PEG (10–20 phr) PEO-b-PBA (PEO/PBA = 0.36, 5 phr). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3120–3125, 2002