蓖麻油聚氨酯／聚取代乙烯互穿网络聚合物作为带锈涂料及粘合剂的可能性

在室温用氧化还原引发剂将蓖麻油、甲苯二异氰酸酯及取代乙烯合成了蓖麻油聚氨酯／聚取代乙烯互穿网络聚合物（ＩＰＮ），研究了不同组成对带锈铁板搭接剪切强度的影响。指出搭接剪切强度随取代乙烯均聚物的玻璃化温度增加而增。ＮＣＯ／ＯＨ之比愈大，搭接剪切强度也愈大。以蓖麻油聚氨酯／（丙烯腈－苯乙烯）共聚物的反应液作为带锈铁板的涂料，其涂膜性能良好。用扫描电镜观察了此种涂料与带锈铁板的结合状态，并讨论其成因。     

超疏水性聚二甲基硅氧烷膜的制备及其表面吸附性研究

采用简单的激光刻蚀方法制备了具有类“菜花”状多级结构的粗糙聚二甲基硅氧烷(PDMS)膜, 并用CCD与高敏感性微电力学天平观察和测量PDMS表面对水的吸附情况. 结果表明, 该膜表面具有超疏水性, 同时对水滴具有超低的吸附力. 还对其表面特殊多级结构产生的机理进行了分析, 并探讨了在化学组成和表面结构对超疏水性以及吸附性产生的影响.     

Thermoanalytische Untersuchung von Baumaterialien Ägyptischer Mumiensärge

Egyptian mural paintings, polychromatic sculptures and mummy coffins exhibit a remarkable durability, ranging over millennia. This phenomenon can be explained by the dry, non-corrosive climate of the Nile valley and/or by the knowledge and experience with which Egyptian craftsmen developed skills to conserve items and materials for eternity. Investigations concerning the timber and covering or protecting layers of mummy coffins are reported. The experimental results were obtained by means of thermal analysis and X-ray diffraction. The interpretation sheds light on the ancient techniques applied.This revised version was published online in November 2005 with corrections to the Cover Date.     

Thin films of polymer mimics of cross-linking mussel adhesive proteins deposited by matrix assisted pulsed laser evaporation

Mussels secrete specialized adhesives known as mussel adhesive proteins, which allow attachment of the organisms to underwater marine environments. Obtaining large quantities of naturally derived mussel adhesive proteins adhesives has proven to date rather problematic, thus, synthetic analogs of mussel adhesive proteins have recently been developed. We report deposition of 1:100 and 1:1000 poly[(3,4-dihydroxystyrene)-co-styrene)] mussel adhesive protein analogs by matrix assisted pulsed laser evaporation (MAPLE) using an ArF* excimer laser source. The deposited films have been evaluated for their antifouling behavior. The MAPLE-deposited synthetic mussel adhesive protein analog thin films are homogenous and adhesive, making the use of these materials in thin film form a viable option.     

Substrate‐Induced Controllable Wrinkling for Facile Nanofabrication

In this work, we report a facile and effective strategy to generate patterned wrinkles. This strategy includes first adhering a thin poly(dimethylsiloxane) (PDMS) film (<82 µm) on porous conductive adhesive tape (CAT), followed by sputter coating of Au onto PDMS under vacuum condition, which results in formation of patterned wrinkles on the Au‐PDMS bilayer. CAT was found to induce local stretching of PDMS thin film, which was the key for controlled wrinkle formation. Compared with previous wrinkling methods, our strategy is simpler and gives smaller feature sizes (down to 300 nm).

     

Formulation and Evaluation af a Novel Adhesive Film for Use in Composite Patch Repair

The current work focuses on the testing of a novel material used as an adhesive film in Composite Patch Repair (CPR). A series of Differential Scanning Calorimetry (DSC) results along with various curing cycles not only led to the optimum material composition but also demonstrated the compatibility to the composite pre-impregnated patches. This in turn was subjected to mechanical testing including shear strength measurements. The substrate was chosen to be 2017 T4 aluminium alloy which is customarily used in the aerospace industry, taking into account that CPR is a technique mainly applied in this field. The subsequent surface preparation of the specimens was investigated for the specified context resulting to the selection of the Ferric Sulphate Sulphuric acid etching process. Finally, a series of specimens representing actual skin repairs were created and subjected to cyclic loading, specifying the suitability of the novel material, compared to commercially available materials.     

Evaluation of polyblends of cottonseed protein and polycaprolactone plasticized by cottonseed oil

Recently, there has been an increasing trend toward replacing conventional fossil-based plastics with bioplastics that are eco-friendly and biodegradable. In this work, blends of polycaprolactone (PCL) and cottonseed protein plasticized with cottonseed oil were made and analyzed for their mechanical, adhesive, and thermal properties. The addition of water-washed cottonseed meal (WCSM) to PCL increased the Young’s modulus but decreased the tensile strength and elongation-at-break of PCL. The addition of cottonseed oil to the PCL/WCSM blend kept the tensile strength about the same but enhanced the elongation. The PCL blends with WCSM and cottonseed protein isolate gave about the same mechanical properties, both somewhat better than the PCL/soy protein isolate blend. As plasticizers, cottonseed oil performed slightly better than coconut oil, both better than poly(ethylene glycol). The addition of WCSM and cottonseed oil (up to a PCL:WCSM:plasticizer ratio of 60:40:20) did not change the adhesive performance of PCL on fiberboard. Thus, the combination of PCL/cottonseed protein/cottonseed oil seems to be a viable bioplastic, and one possible application for this material may be in the hot melt adhesive area.     

Multi-frequency dynamic-mechanical thermal analysis of methyl methacrylate adhesive (MMA)

The paper presents the results of Dynamic-Mechanical Thermal Analysis (DMTA) for a selected methacrylate adhesive at the frequency range from 1 to 50?Hz and the heating rate of 1 and 3?°C/min, in the range from –70?°C to 180?°C. On the basis of the test results, the glass transition temperature was evaluated for three calculation methods. Master curves were also designated for three different reference temperatures: –20, +20 and +60?°C. Master curves were calculated using shift factors a_T - calculated by numerical method.     

Ambient curable latex films and adhesives based on natural rubber bearing Acetoacetoxy functionality

The study described in this paper first demonstrates that a newly modified form of natural rubber, namely graft copolymers of natural rubber with poly (acetoacetoxyethyl methacrylate), NR‐g‐PAAEM, is able to undergo a cross‐linking reaction at room temperature by reaction with a water dispersible polyisocyanate based on hexamethylene diisocyanate (poly‐HDI). Attenuated total reflectance Fourier transform infrared (ATR‐FTIR) analysis indicated that amide groups were formed by the reaction of the acetoacetyl groups (AcAc) present in the grafted poly (acetoacetoxyethyl methacrylate) (PAAEM) chains with the poly‐HDI. This observation was accompanied by a noticeable increase in the tensile strength of the NR‐g‐PAAEM latex films when adding poly‐HDI to the latex prior to film formation. DMTA analyses also revealed a shift in the tan δ peaks, corresponding to the transitions of both NR‐g‐PAAEM and free PAAEM phases, to higher temperatures. These results provide firm evidence of cross‐linking between NR‐g‐PAAEM chains by reaction with poly‐HDI during film formation under ambient conditions. Adhesives for bonding wood to wood based on the NR‐g‐PAAEM latex were then prepared, using poly‐HDI as the cross‐linker. The lap shear strength of the resulting adhesives exhibited a maximum value of 2657 KPa when a poly‐HDI:AAEM molar ratio of 3:1 was employed. It was also observed that the adhesive attained about approximately 89% of the highest lap shear strength after it was allowed to set at 30°C for 24 hours. Hence, the use of poly‐HDI in cross‐linking NR particles bearing grafted PAAEM offers great potential for developing latex adhesives and coatings capable of curing under ambient conditions.     

Biofunctionalized Electrospun PCL‐PIBMD/SF Vascular Grafts with PEG and Cell‐Adhesive Peptides for Endothelialization

Artificial small‐caliber vascular grafts are still limited in clinical application because of thrombosis, restenosis, and occlusion. Herein, a small‐caliber vascular graft (diameter 2 mm) is fabricated from poly(ε‐caprolactone)‐b‐poly(isobutyl‐morpholine‐2,5‐dione) (PCL‐PIBMD) and silk fibroin (SF) by electrospinning technology and then biofunctionalized with low‐fouling poly(ethylene glycol) (PEG) and two cell‐adhesive peptide sequences (CREDVW and CAGW) with the purpose of enhancing antithrombogenic activity and endothelialization. The successful grafting of PEG and peptide sequences is confirmed by X‐ray photoelectron spectroscopy. The suitable surface wettability of the modified vascular graft is testified by water contact angle analysis. The surface hemocompatibility is verified by platelet adhesion assays and protein adsorption assays, and the results demonstrate that both platelet adhesion and protein adsorption on the biofunctionalized surface are significantly reduced. In vitro studies demonstrate that the biofunctionalized surface with suitable hydrophilicity and cell‐adhesive peptides can selectively promote the adhesion, spreading, and proliferation of human umbilical vein endothelial cells. More importantly, compared with control groups, this biofunctionalized small‐caliber vascular graft shows high long‐term patency and endothelialization after 10 weeks of implantation. The biofunctionalization with PEG and two cell‐adhesive peptide sequences is an effective method to improve the endothelialization and long‐term performance of synthetic vascular grafts.