Photoprotection of Wood Using Polyester-Type UV-Absorbers Derived from the Reaction of 2-hydroxy-4(2,3-epoxypropoxy)-benzophenone with Dicarboxylic Acid Anhydrides

Abstract

Polyester-type UV absorbers were created by reacting the epoxy-functionalized UV absorber 2-hydroxy-4(2,3-epoxypropoxy)-benzophenone (HEPBP) with maleic, phthalic, or succinic anhydride. The ability of the UV absorbers to photostabilize wood was then examined. Fourier transform infra-red (FTIR) spectroscopy confirmed that HEPBP reacted with phthalic anhydride to create a polyester that preserved the UV-absorbing benzophenone group. There was less evidence that the polyester was formed when HEPBP was reacted with maleic or succinic anhydride. HEPBP-phthalic anhydride was the most effective UV absorber at photostabilising wood. This UV absorber showed increased UV absorption around 270 nm, formed a leach-resistant film at wood surfaces and was able to restrict both weight and tensile strength losses of thin wood veneers during accelerated weathering, unlike chromium trioxide and a UV absorber-hindered amine light stabilizer. We conclude that polymeric polyester-type UV absorbers show promise as a way of photostabilizing wood and briefly discuss how more effective systems could be developed in future.     

Accelerated weathering of pectin/poly(vinyl alcohol) blends studied by spectroscopic methods

The blends of pectin (PEC) and poly(vinyl alcohol) (PVA) at different components ratios were prepared by mixing in water. Thin polymeric films of PEC/PVA blends and pure polymers were obtained by casting method. All samples were then artificially aged using Suntest apparatus (Atlas) up to 780 h. The changes in chemical structure during sample ageing have been monitored by infrared and ultraviolet‐visible absorption spectroscopies. The first stage of weathering (up to ～ 300 h) was very slow and alteration of chemical structure was negligible in all samples. Prolonged ageing (>300 h) caused more significant degradation processes. FTIR spectra exhibited the highest changes in hydroxyl and carbonyl band ranges indicating the efficient photooxidation of macromolecules. The mechanisms of the observed processes have been discussed. It was found that PVA undergoes faster photoxidative degradation than pectin aged at the same conditions. The PEC/PVA blends exhibited the improved resistance to weathering comparing with both polymers aged individually. Mutual stabilization effect can be explained by intermolecular interactions between PEC and PVA confirmed by spectroscopic methods. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

风化细粒钛铁矿及伴生金红石的选矿试验研究

就云南某地风化严重的细粒钛铁矿及伴生金红石进行了选矿试验研究,在采用弱磁选—强磁选工艺不能获得理想的指标后,采用弱磁选—强磁选—还原焙烧—弱磁选—浮选—重选—酸浸的工艺流程,获得了理想产品,铁精矿品位61.08%,回收率6.23%;钛铁精矿TiO2品位49.69%,回收率87.33%;金红石精矿TiO2品位86.57%,回收率11.77%。     

鄂尔多斯盆地东部奥陶系风化壳古地貌特征嬗变及地质意义

鄂尔多斯盆地奥陶系风化壳气藏的发育与前石炭纪古地貌格局密切相关,目前主要认为发育西高东低的古地貌格局,自西向东依次发育岩溶高地、岩溶斜坡及岩溶盆地的古地貌单元。但随着勘探的深入,在盆地东部地区奥陶系早期认为的岩溶盆地区已经发现了大量代表了较强岩溶作用的岩溶角砾岩等地质现象,因此有必要从古地貌动态演化角度重新认识影响岩溶古地貌发育的内外因素,研究地质历史中奥陶系风化壳古地貌的性质嬗变,指导对区域储集空间发育规律的进一步研究与预测。以盆地东部奥陶系顶部风化壳古地貌恢复为目的,综合研究了古地理背景、残留地层厚度、古岩溶特征等因素。认为早期在盆地中东部存在一个大范围的岩溶古高地,形成了岩溶型储集空间,但后期盆地东部逐渐演变为古岩溶盆地,形成了现今的前石炭纪古地貌格局,并造成早期形成的溶蚀类储集空间被大量充填,整体储层较致密,但由于溶洞塌陷形成的裂缝网络沟通了白云岩晶间孔储集空间,局部仍然可以保留有较好的储层,是值得重视的勘探目标。     

PE基木塑复合材料的光稳定化及其耐候性能研究

以高密度聚乙烯为树脂基体,同时并采用两种自主开发的木塑专用耐候母粒对其进行光稳定化改性,制备了PE基木塑复合材料,并对其耐候性能进行了研究。结果表明,耐候母粒LS-1和LS-2均对PE基木塑复合材料有较好的抗老化作用。经1000h的氙灯加速老化后,光稳定化改性前后的木塑复合材料的拉伸性能变化不大;改性后的木塑复合材料的冲击强度保持率明显提高,色差明显减小,其中LS-2的效果更佳。     

水泥稳定炉渣碎石的强度性能

以生活垃圾焚烧炉渣集料替代部分天然集料制备水泥稳定炉渣碎石试件,然后通过无侧限抗压强度试验和劈裂试验测试试件的强度性能,分析了炉渣集料熟化时间及粒径、混合料养生龄期和养生温度、水泥用量对水泥稳定炉渣碎石强度性能的影响,并比较了水泥稳定炉渣碎石强度性能与水泥稳定碎石的差异.结果表明：炉渣集料压碎值随其熟化时间的延长而降低,水泥稳定炉渣碎石7d无侧限抗压强度随炉渣集料熟化时间的延长而提高;掺熟化30d炉渣集料(0～95mm)的水泥稳定炉渣碎石7d无侧限抗压强度达到40MPa;炉渣集料粒径越大,水泥稳定炉渣碎石7d无侧限抗压强度越低;水泥稳定炉渣碎石养生龄期越长、水泥用量越大、养生温度越高,其无侧限抗压强度和劈裂强度越高.     

山区地基设计探讨

通过对山区地基的综合分析,介绍了山区地基设计的主要内容,并分析了地基设计中常见问题的应对措施,指出挡土墙设计是影响地基稳定性设计的重要内容,对减少工程隐患,避免工程质量问题的发生以及延长工程的使用寿命具有重要意义。     

宁波湾头大桥氟碳面漆使用调查

考察宁波湾头桥氟碳面漆使用1年后的表面状态与耐候性能,并对大桥所使用的常温固化氟碳面漆的设计依据与配方性能进行介绍.     

地铁工程球状风化专题勘察方案研究

球状风化(俗称"孤石")对地铁盾构工程施工极为不利.本文结合工程实例,论述了地铁工程开展球状风化专题勘察的必要性,并以深圳某地铁工程为例,通过分析球状风化对地铁工程不同工法的影响以及处理孤石的方法,合理地推荐了球状风化专题勘察的实施范围;通过对不同类型勘察方案进行多因素综合比较,推荐了专题勘察布置方案,并就专题勘察的实...