木质纤维/塑料复合材料的发展现状及应用

木质纤维/塑料复合材料是以木质纤维材料为基本体,与塑料通过不同的复合途径制成的一种新型复合材料,综合了木质纤维与塑料的性能特点,因而用途广泛.作者介绍了木质纤维/塑料复合材料的复合工艺、界面特性和改性处理以及产品的应用前景.     

工程塑料泵叶轮强度计算

针对目前广泛使用的工程塑料泵叶轮，对叶片和盖板进行受力分析，得出不同比转数叶轮叶片所对应的系数k1。根据简化模型并应用轮盘理论，详细推导了塑料泵叶轮强度计算公式。结合应用实例，对几种常用工程塑料泵叶片和盖板的强度进行了校核。计算和分析表明：工程塑料中，UHMWPE和PP的部分牌号可以满足强度要求；而PPO和PVDF由于性能优良，可以满足强度要求，从而为泵用工程塑料的选择和使用提供了理论依据。     

二氧化碳基塑料降解性能的研究

[目的]研究二氧化碳基塑料的降解性能.[方法]以PPC为原料,通过生物降解、热氧化降解和光降解研究了PPC的降解性能.利用乌式粘度计测定了降解过程中PPC塑料的分子量变化;利用傅里叶变换红外光谱仪表征了降解过程中PPC的红外光谱特性.[结果]PPC薄膜在27℃恒温培养箱中生物降解15 d后,降解效果明显.180℃热氧化降解36 h,PPC塑料的分子量减少了63％.光氧化降解5d后,PPC塑料的分子量减少了约85％.[结论]与生物降解相比,PPC塑料的热氧化和光降解程度更为明显.     

染色木塑复合材料—茶合板制造工艺研究

采用正交试验方法，在不同试验条件下压板，分析讨论了单板染色，酚醛树脂的种类，单板浸渍和热压工艺参数对染以木塑复合材料－茶合板物理力学性能的影响，确定了所考察因素中最佳工艺条件。     

泡沫塑料雕塑技术在鸵鸟形态标本制作中的应用研究

传统的形态标本制作是用棉花稻草等物做填充,或用钢筋、木头、石膏做成假体,存在着形态不逼真、易变形、易发霉、假体的制作工艺复杂、耗材多、重量重、易破损等缺点。本试验采用塑料泡沫雕塑技术成功制作出鸵鸟形态标本,具有形态逼真、不易变形、不易霉变、不易损坏、重量轻、易加工、工艺简单等优点。本试验对鸵鸟养殖业的生产、教育、科研及科学普及都具有积极的意义,对动物形态标本的制作也起到了积极作用。     

棉花机械辅助去雄新方法的探讨

通过试验表明，采用塑料管去雄法较传统的徒手去雄法，成铃率提高21％，畸形铃率下降28．7％，制种产量显著提高，且提高了制种效率。     

滇中地区塑料温室光温环境的测试分析

 针对滇中地区广泛使用的塑料温室类型的温度、湿度、光照强度进行了全年的观测研究,其中以温度为测试重点,并对测试所得的大量数据进行了统计分析。结果表明:滇中地区冬季夜晚普通单栋塑料大棚内最低温度低于5 ℃的天数超过2／3,1,2月份则达到94.9%;冬季单栋塑料大棚白天升温作用明显,处于封闭状态时室内气温可超过40 ℃,而夜间保温效果不明显,最低气温等于或低于室外气温;冬季太阳辐射强,有利于大棚蓄热升温。夏季室外最高气温基本低于30 ℃,因此大棚的最便捷的散热方式就是利用室外较低温度的空气进行通风散热。     

Factors (type,colour, density,and shape) determining the removal of marine plastic debris by seabirds from the South Pacific Ocean: Is there a pattern?

1. While floating near the sea surface plastic debris interacts with a number of external factors, including many different organisms. Seabirds have the most extensive documented history of interactions with plastics, through ingestion, entanglement, and nest construction.
2. In the present study, eight seabird species from the South Pacific Ocean were used as a proxy to determine potential patterns of removal of marine plastic debris, and three hypotheses were tested in relation to their feeding habits and nesting areas.
3. Plastics from abiotic compartments (Chilean continental coast, South Pacific Gyre, and Rapa Nui beaches) and biotic compartments (surface-feeding seabirds, diving seabirds, and nesting areas) were compared, according to their type, colour, shape, and density.
4. Continental beaches had a relatively wide range of colours and shapes, with many non-buoyant plastics. Samples from the South Pacific Gyre (SPG) and Rapa Nui (Easter Island) beaches comprised mainly hard, rounded, buoyant, and white/grey plastics.
5. These results indicate that the composition of floating plastics from terrestrial sources changes during transport with oceanic currents, reducing the proportion of prey-like plastics present in the subtropical gyres.
6. The stomach contents of surface-feeding and diving seabirds were dominated by hard, white/grey, and round plastic items, similar to plastics from the SPG, suggesting non-selective (accidental or secondary) ingestion.
7. Nesting areas had a more variable composition of brightly coloured plastics, suggesting a pattern of selective removal of plastics by seabirds, probably from oceanic sources.
8. The present study reveals extensive interactions of seabirds with plastics on a broader scale, which is highly relevant given that the impacts of plastics on seabirds are increasing worldwide, compromising their efficient conservation.

     

木粉丁二酰化改性制备生物基塑料

[目的]制备出具有较好力学性能的注塑级生物基塑料.[方法]以胡桑枝条木粉为原料,经球磨预处理后,于二甲亚砜-四乙基氯化铵复合溶剂体系中部分溶解后,以丁二酸酐为酯化试剂,对二甲氨基吡啶为催化剂,进行酯化改性,制备出具有较好力学性能的注塑级生物基塑料.[结果]通过试验对比,得出最好的试验参数为:当木粉原料与丁二酸酐的质量比为1∶1,在60℃下溶解1h后再反应1h.在此条件下改性产物的增重率为103.7％,可以达到最优的力学性能,其拉伸强度和弯曲强度分别能达到33.4和41.9 MPa,已经达到一般塑料的力学性能.[结论]研究可为木质纤维类生物质全组分综合高值利用提供参考.