天然胶乳压敏胶的合成

一、前言 压敏胶粘制品主要用于包装行业,如生产OPP封箱胶带、牛皮纸胶带等。随着我国经济的发展,近几年压敏胶粘制品的产量增长很快。据统计,我国压敏胶带的产量1989年是2.2亿m~2,1991年为8亿m~2,1992年达到15亿m~2。早期的压敏胶粘剂以橡胶溶剂型为主,具有易燃易爆,污染环境,成本高     

沾水胶带及其胶粘剂的研制

一、前言沾水胶带是一种新型压敏胶带,在干燥状态下不具粘附性,但在与湿的基材接触或经水润湿后即刻产生粘接力。这种胶带是由水再生粘性的胶粘剂涂布于基材上干燥而成。它与通用的橡胶型压敏胶带相比有如下优点:(1)橡胶型胶粘剂常用汽油为溶剂,易燃不安全。沾水胶带的的胶粘剂则以水为溶剂,安全易得。(2)橡胶型胶带必须在基材上涂隔离剂,便于解卷。而沾水胶带干燥后不具粘性易于解卷,不必在基材上涂隔离剂。(3)水再生粘性胶粘剂较橡胶型压敏胶粘剂的原料易得,成本较低,     

国外技术情报

<正> 221 VHB 丙烯酸系泡沫压敏胶带这种胶带具有胶粘剂面粘合的各种优点,和双面压敏胶带的使用方便特点。它的结构是以丙烯酸酯共聚体泡沫作基材,其两面涂布耐候优良的压敏胶,一面贴     

乳液型丙烯酸压敏胶带生产技术的进展

以乳液型丙烯酸酯胶粘剂来制造压教胶带，其产量在国内外均日益增加，近来在丙烯酸酯树脂聚合时采用各种共聚，交联，嵌段等工艺或调换乳化剂，改变增粘剂等措施来使乳液颗粒变小，含固量增加，同时胶带制成后持粘力与剥离强度也有改进，乳液型丙烯酸酯压敏胶带的耐水性也随之提高。目前，涂布设备也进行了一系列改进，以提高自动化程度，甚至采取各种新技术，如辐射固化等手段，用来提高产量，降低成本，并预计至本世纪末，丙烯酸酯类胶带将开拓至更多的应用领域。     

对丙烯酸系压敏胶粘剂某些性能的改进

丙烯酸酯类压敏胶粘剂,是目前仅次于橡胶类用得最多的压敏胶粘剂。按其形态分类,有乳液型、溶剂型和无溶剂型三种。它们各自都有不足之处,下面分別谈谈对其改进方法。一、对乳液型压敏胶某些性能的改进乳液型压敏胶是近年来发展较快的品     

亚太地区压敏胶带市场动向

亚太地区经济在急速发展,胶带市场也不例外。本文就日本、台湾、南朝鲜为主的亚太地区胶带市场介绍如下。一、各国胶带产量 1987年亚太地区压敏胶带总产量估计23亿平方米。最大生产国日本占总产量的43.9％,约10亿平方米;其次是台湾,占总     

丙烯酸乳液型胶粘剂的开发动向(一)

近年来,胶粘制品发展很快,已由压敏胶带、标签,发展到汽车工业、电子设备、医疗用品等所有产业领域。在这里着重介绍的是:关于胶粘制品的市场动向及丙烯酸乳液型胶粘剂的质量设计因数、粘弹性的技术动向。一、市场动向日本胶粘制品在1987年就已达到3400亿日元。其中工业用压敏胶带类为1520亿     

弹性体胶粘剂的开发近况

本文介绍了弹性体胶粘剂三大产品(腔粘剂、压敏胶带和密封剂)的开发近况,其胶粘剂产品中主要介绍了结构型、非结构型、水基型和橡胶加工工艺用胶粘剂四种类型。     

日推出改性丙烯酸酯粘合剂

近年来美国的胶粘带行业与胶粘剂其他各分支的表现是基本一致的，环境问题、经济问题和降低成本的问题仍是影响经济效益和产品性能的三大主要因素。胶粘带是压敏胶粘剂(PSA)的两大基本应用之一。据美国一家市场研究公司Freedonia的统计预测，到2004年，美国压敏胶带产量将以超过6%的速度增长，达到近250亿m^2，价值205亿美元。     

PS—4型电影接片专用压敏胶带

我所研制成功PS—4型电影接片专用压敏胶带,介绍如下: 一、特性与用途: PS—4型电影接片专用胶带是用聚酯薄膜为基材,丙烯酸酯共聚物为胶粘剂的新型压敏胶带。它具有无色、无味、透明度高、粘性强、耐热、耐老化等特点,适用于电影制片厂、胶片厂及电影放映部门等单位剪接影片或录音带之用。二、技术条件: 1、胶带规格: 长度: 10米±0.1米 20米±0.2米     

Preparation and surface-active properties of the sodium soaps,mono- and diethanolamides and diol and triol sulfates of cycloaliphatic C21 Di- and C22 Tricarboxylic acids

Cycloaliphatic C₂₁ di- and C₂₂ tricarboxylic acids were prepared by the Diels-Alder reaction of dehydrated castor oil (DCO) fatty acids (containing 48% conjugated and 42% nonconjugated dienes) with acrylic and fumaric acids, respectively. The reaction temperature, time, catalyst concentration, and mole ratio of reactants were varied to get maximum yields of the di- and tricarboxylic acids. The unreacted DCO fatty acids were removed from the products by partition between aqueous methanol and n-hexane. The products were converted to methyl esters and characterized as the substituted cyclohexene derivatives before and after dehydrogenation with Pd/C in xylene, hydrogenation with Pd/C in decalin and oxidation with periodate-permanganate reagent and by mass and proton nuclear magnetic resonance spectrometry. The acids were converted to sodium soaps, mono- and diethanolamides and the corresponding diol and triol sulfates, and the resulting products were evaluated for their surface-active properties. The sodium soaps showed better calcium tolerance and poorer foaming power than sodium oleate. The diethanolamides were inferior to lauroyl diethanolamide in wetting and emulsifying power. The monoethanolamides were better than the respective diethanolamides and lauroyl diethanolamide in wetting property. The diol and triol sulfates were poorer in wetting and emulsifying ability and better in calcium tolerance than sodium lauryl sulfate.     

民用工业中复合材料桁架的应用和发展

本文叙述了复合材料桁架的构造、分类和计算方法,突出了复合材料桁架的优越性能和在民用工业中的应用前景;在分析大量文献资料的基础上阐述复合材料桁架杆件的多种加工工艺,并比较不同截面形式对杆件性能的影响;探讨复合材料杆件的破坏机理和分析方法,介绍节点的类型和各自的特点,提出节点及连接部位存在的关键问题;根据国内外复合材料桁架的研究和应用现状,阐述了复合材料桁架的性能和不同的设计方法,总结归纳影响复合材料桁架性能的关键因素和设计中存在的一些问题,并提出改进杆件设计、节点设计和优化复合材料桁架的建议。     

熟料岩相试样制作方法及典型岩相特征的形成原因

熟料的岩相分析有助于熟料质量的判断及生产过程控制调整。根据多年实践经验,总结了手工和机械磨制岩相试样的方法及注意事项,并对几种熟料岩相特征(孔洞、游离氧化钙、A矿包裹B矿和f-Ca O、晶体尺寸不均和矿巢)进行了举例和形成原因分析。     

Enzymes-Assisted Extraction of Plants for Sustainable and Functional Applications

The scientific community and industrial companies have discovered significant enzyme applications to plant material. This rise imparts to changing consumers’ demands while searching for ‘clean label’ food products, boosting the immune system, uprising resistance to bacterial and fungal diseases, and climate change challenges. First, enzymes were used for enhancing production yield with mild and not hazardous applications. However, enzyme specificity, activity, plant origin and characteristics, ratio, and extraction conditions differ depending on the goal. As a result, researchers have gained interest in enzymes’ ability to cleave specific bonds of macroelements and release bioactive compounds by enhancing value and creating novel derivatives in plant extracts. The extract is enriched with reducing sugars, phenolic content, and peptides by disrupting lignocellulose and releasing compounds from the cell wall and cytosolic. Nonetheless, depolymerizing carbohydrates and using specific enzymes form and release various saccharides lengths. The latest studies show that oligosaccharides released and formed by enzymes have a high potential to be slowly digestible starches (SDS) and possibly be labeled as prebiotics. Additionally, they excel in new technological, organoleptic, and physicochemical properties. Released novel derivatives and phenolic compounds have a significant role in human and animal health and gut-microbiota interactions, affecting many metabolic pathways. The latest studies have contributed to enzyme-modified extracts and products used for functional, fermented products development and sustainable processes: in particular, nanocellulose, nanocrystals, nanoparticles green synthesis with drug delivery, wound healing, and antimicrobial properties. Even so, enzymes’ incorporation into processes has limitations and is regulated by national and international levels.     

Effects of Extraction Temperature and Preservation Method on Functionality of Soy Protein

The effects of extraction temperature and preservation method on the functional properties of soy protein isolate (SPI) were determined. Four extraction temperatures (25, 40, 60, and 80 °C) were used to produce SPI and yields of solids and protein contents were determined. Three preservation methods were also tested (spray-drying, freeze-drying, and freezing–thawing) and compared to fresh (undried) samples for each extraction temperature. No differences in yields of solids and protein were observed among SPIs extracted at 25, 40, and 60 °C; however, SPI extracted at 80 °C yielded significantly less solids and protein. Extraction temperature significantly affected SPI functionality. As extraction temperature increased, solubility and emulsification capacity decreased; surface hydrophobicities, emulsification activities and stabilities, and dynamic viscosities increased; and foaming properties improved. Preservation method also significantly affected SPI functionality. Drying method did not affect the denaturation enthalpies of SPIs, but spray-dried SPIs had higher solubilities, surface hydrophobicities, and emulsification stabilities, and lower viscosities, emulsification activities and rates of foaming than freeze-dried SPI exhibited. Emulsification and foaming capacities and foaming stabilities were similar for both methods of drying. There was significant interaction between extraction temperature and preservation method for all functional properties except emulsification capacity.     

Role of Douglas fir (Pseudotsuga menziesii) carbohydrates in resistance to budworm (Choristoneura occidentalis)

The current year's growth of Douglas fir contains galactose, unusual in that this carbohydrate makes up 78.7% of the total carbohydrate fraction. An agar diet study was undertaken to determine the effects of galactose, other carbohydrates, and terpenes on western spruce budworm larval mortality, growth rate, and adult biomas production. All concentrations of the carbohydrates and terpenes tested, as well as other mineral elements not tested, were typical of the current year's foliage of Douglas fir. In experiment I, the diet containing 5.61% total carbohydrate did not significantly affect larval mortality when compared to the control diet. However, diets containing 9.45% and 15% total carbohydrate concentrations significantly increased larval mortality 64% and 96.1%, respectively, when compared to the control. Also in experiment I, terpenes alone (78.9% morality) and terpenes in combination with 9.45% and 15% total carbohydrates significantly increased larval mortality (97.2% and 100%, respectively) when compared to mortality on the control diet (44%). To determine which carbohydrate was causing the adverse effect, 6% glucose, 6% fructose, and 6% galactose were placed individually and in combination with terpenes in diets in experiment II. The 6% galactose diet significantly increased larval mortality and reduced growth rate when compared to the control, glucose, and fructose diets. Glucose resulted in 16% less larval mortality, significantly enhanced female larval growth rate and pupal weight, but did not affect male larval growth rate and pupal weight, when compared to the control. Fructose resulted in a significant decrease in larval mortality and a general trend of enhanced female and male larval growth rate and pupal weight. Larval mortality on terpenes alone was not significantly different from the control, but terpenes with 6% galactose increased larval mortality and decreased female and male growth rate and pupal weight significantly when compared to glucose-terpene and fructose-terpene diets. No significant interactions were found between carbohydrates and terpenes in either experiment.     

COMBINED INNOVATIVE HEAT PUMP DRYING TECHNOLOGIES AND NEW COLD EXTRUSION TECHNIQUES FOR PRODUCTION OF INSTANT FOODS

There is an increased demand for convenient foods including ready-to-eat and instant products. These products are desired with minimum concentration of synthetic chemicals. This creates challenges for the food industry and dryers manufactures to develop new technologies to process difficult-sensitive materials and to supply final products with high quality and improved properties. Fruits and vegetables are mainly composed of water, carbohydrates, proteins and lipids. Due to modification of chemical and physical bonds the compounds the material becomes viscous and sticky during processing. Conventional dryers have limitations in handling such sensitive materials. Heat pump dryers have been applied in the production of a diversity of ready-to-eat foods and dried instant products for the last five years at SINTEF-NTNU. Besides being energetically efficient and environmentally friendly, the heat pump drying technology provides a wide range of drying conditions as required to produce powders with improved characteristics. This work describes the new technologies and processing line for the production of instant foods as well as the measurements on the properties and quality attributes for raw, intermediate and final instant products.     

Environment and colour: The technological interface

Technology and colour are viewed as interfaces between the environment, humans and human activity. Examples are provided of ways of facilitating and improving access to and use of colours by commercial users of colour coatings through improvements in the accuracy of measuring and displaying colour. By analogy, the task of providing effective interfaces within the coatings industry, between the coatings industry and the environment and between the coatings industry and the public and political domain are discussed. Examples of information shortfalls are cited to illustrate how distortions arise. Examples of more effective, integrated technological, organisational and political interfacing are culled from the author's experiences.     

毒死蜱、联苯菊酯在室内和室外土壤中的消解动态及土壤化学屏障研究

[目的]探讨毒死蜱和联苯菊酯在室内外土壤中的消解动态,并预测2种农药作为土壤化学屏障防治白蚁的有效期。[方法]采用气相色谱法测定不同时期土壤中毒死蜱和联苯菊酯的残留量并采用土壤穿透法测定2种农药在土壤中的生物活性。[结果]毒死蜱在室内和室外的半衰期分别为51.3、39.5 d,联苯菊酯在室内和室外的半衰期分别为31.3、44.5 d。毒死蜱和联苯菊酯抗白蚁穿透的最低有效质量分数分别为6.15、5.78 mg/kg,并结合消解动态方程预测出毒死蜱和联苯菊酯作为土壤化学屏障中有效成分的有效期在室内分别为195、29.1 d,在室外则分别为158.4、56.1 d。[结论]得到的白蚁防治有效期结果较好,为白蚁的化学防治提供理论依据。     

工业纯锆产品的性能和应用

1前言锆(Zirconium)的元素符号为Zr,位于元素周期表中第IV-B族元素,银白色金属。它具有熔点高、密度适中、良好的强度和塑性匹配,而且热中子吸收