吸湿剂对吹塑成型聚乙烯微孔薄膜性能的影响

采用普通吹塑方法，以可发性功能母粒与聚乙烯混合料为原料制成微孔薄膜，研究了吸湿剂山梨醇、乙二醇、壳聚糖对聚乙烯微孔薄膜力学性能、透气透湿性能的影响。结果表明：山梨醇、乙二醇和壳聚糖会不同程度地降低薄膜的力学性能，其中壳聚糖降低PE微孔薄膜拉伸的程度最大；但另一方面，三种吸湿剂都能增加PE微孔膜的透湿性和透气性，其中山梨醇改善PE微孔膜的透湿、透气性的作用最大。     

浓缩甲醇用高性能选择渗透膜

日本相膜中央研究所开发了一种新的甲醇选择渗透膜,它的分离性能超过了人们熟悉的分离甲醇和水的膜——硅膜,它使浓度为7～8%的甲醇溶液通过一次渗透即可将浓度提高至62～80%。在聚乙烯类聚合物上接枝了硅氧烷的硅氧烷接枝膜,通过一次渗透可将甲醇的浓度从7%提高至62～65%。厚     

专利文摘

本发明涉及一种清洗剂,其通过二丙二醇甲醚、异构烷、脂肪醇聚氧乙烯醚、失水山梨醇脂肪酸酯、乙二醇丁醚、丙二醇醚、链烷烃以及遮味除味剂以如下质量百分含量的比例进行混合反应而制成：二丙二醇甲醚5～10％;异构烷30～40％;脂肪醇聚氧乙烯醚1～2％;失水山梨醇脂肪酸酯3～5％;乙二醇丁醚5～10％;丙二醇醚5～10％;链烷烃40～50％;遮味除味剂0．2～1％。     

土壤培养条件下控释肥高分子残膜降解特性研究

研究了控释肥高分子残膜在模拟土壤培养条件下的降解特性.采用傅里叶变换红外光谱(FT-IR)、示差扫描量热(DSC)、粘度法等方法,对添加质量分数为0%、15%的淀粉的控释肥高分子残膜的降解性能进行了分析.结果表明,控释肥高分子残膜具有降解性,在土壤培养条件下,含淀粉控释肥聚乙烯残膜较不含淀粉控释肥聚乙烯残膜更易降解.随...     

中国专利

<正>一种透明多因子降解改性聚乙烯膜及其制备方法本发明公开了一种透明多因子降解改性聚乙烯膜及其制备方法,属于高分子新材料制备技术领域。配方包括聚乙烯、磺化聚醚醚酮、苯基磷酸锌、马来酸酐接枝1-辛烯-乙烯共聚物、聚乙烯醇-聚甲基丙烯酸甲酯共聚物、微生物营养添加剂、聚乙二醇(PEG 400)、山梨醇聚醚、硬脂酸锰、甲基乙烯基醚马来酸酐共聚物、壳寡糖、丙交酯、环氧基硅烷偶联剂和叶腊石细粉,通     

静电纺丝法制备聚乙烯吡咯烷酮/含氢硅油复合纤维膜及气体过滤性能的研究

将聚乙烯吡咯烷酮与含氢硅油共混作为纺丝溶液,用静电纺丝法制备了聚乙烯吡咯烷酮(PVP)/含氢硅油复合纤维膜,考察了PVP和含氢硅油用量对空气过滤效率的影响。研究发现,PVP含量7%,硅油含量14%,无水乙醇作为溶剂配制溶液,通过静电纺丝制备的复合纤维膜空气过滤效率达到81%,过滤效率达到最高。同时,利用红外光谱仪(FTIR)和扫描电子显微镜(SEM)对复合材料的结构和形貌进行了表征。通过扫描电子显微镜(SEM)得出结论,随着PVP添加量的增大,纺丝直径显著增大,纺丝的排列方式由缠绕变为交错。含氢硅油可以减少表面缺陷并降低水蒸气和溶剂对纤维膜的破坏。通过红外光谱仪(FTIR)得出结论,PVP含量7%,硅油含量14%对应样本红外图谱,同时具有PVP和含氢硅油的特征吸收峰。     

大马士革工艺中电镀铜层杂质对其性能的影响

分别采用聚醚胺类物质、聚乙烯亚胺类物质和聚酰胺类物质作为大马士革铜互连电镀工艺的整平剂，得到杂质含量不同的Cu膜层，通过计时电位测试分析了不同整平剂对膜层杂质含量的影响机制。研究了杂质含量对Cu膜层自退火速率、应力和电阻率的影响。结果表明，膜层中杂质含量过高会引起Cu膜层的电阻和应力升高。采用聚乙烯亚胺类物质或聚酰胺类物质作为整平剂时电镀所得Cu膜层的杂质含量都较低。     

聚砜平板超滤膜的制备及性能优化

采用相转化法制备聚砜(PSF)平板超滤膜,通过正交试验确定了较佳制膜条件和各影响因素对膜性能的影响程度(PSF含量>溶剂种类>PVP含量>蒸发时间).在综合考虑经济性和膜性能优化的前提下,由单因素试验探讨了PSF含量、添加剂聚乙烯吡咯烷酮(PVP)含量及第2种溶剂N-甲基吡咯烷酮、二甲基亚砜的添加量对膜性能的影响.结果表明,最优化制膜条件为:PSF和PVP的质量分数分别为13.5%和3%,溶剂为二甲基亚砜和二甲基甲酰胺混合物且体积比为1:5,蒸发时间为10 s.在此条件下,膜将保持原有高截留率并使纯水通量得到较大提高.     

复合载体扩散/阻隔特性的调控与乙烯聚合反应器的强化

为在单一反应器中生产宽/双峰分子量聚乙烯,强化乙烯聚合反应过程,实现分子尺度混合的原位化学合成,并有效降低投资、生产成本和能耗。本工作提出制备一种具有扩散/阻隔特性的核壳结构颗粒作为聚烯烃催化剂的载体,并进行动力学特性的调控。即采用相转化制膜的方法,制备以硅胶(SiO2)为核、聚苯乙烯丙烯酸(PSA)为壳的核壳结构颗粒,然后通过浸渍法,将具有不同反应特性的催化剂活性分子分别组装在核壳结构颗粒中,获得负载型双功能催化剂。其关键技术是以PSA膜为小分子传递扩散的控制开关,利用乙烯、氢气分子和-烯烃分子在膜中扩散特性的差异,以及Cp2ZrCl2、TiCl3和TiCl4等活性组分在动力学上的差异,构建膜内、膜外两种微化学环境,使得活性组分在不同的气氛下分别制备低分子量、低支化的聚合物链和高分子量、高支化度的聚合物链,形成高性能双峰聚乙烯的新工艺。比较三种双峰聚乙烯反应器组合的能耗,表明在单一流化床中采用复合催化剂生产双峰聚乙烯产品能够强化乙烯聚合反应器,能耗大幅下降。同时,通过活性组分和膜厚的调节,实现对聚乙烯分子量分布的调控。     

非溶剂添加剂对聚醚砜中空纤维膜的结构调控

采用非溶剂致相分离法，以聚醚砜(PESU)为膜材料、N，N-二甲基乙酰胺(DMAc)为溶剂、水为非溶剂添加剂、聚乙烯吡咯烷酮(PVP)为改性致孔剂，纺制了不同非溶剂水含量(质量分数)以及不同湿态壁厚的PESU中空纤维膜，通过改变纺丝溶液配方中水含量和膜丝湿态壁厚来研究中空纤维膜结构的调控机制，考察了膜丝的外表面孔径及分布、内部孔隙率、干燥收缩比、爆破压力等参数。结果表明，纺丝溶液配方中水含量的提升以及湿态壁厚的增加均可以增大膜丝外表面平均孔径，在湿态壁厚为60 μm、水含量为7%时，可以使得中空纤维膜外表面平均孔径达到最大值0.557 2 μm，相较于湿态壁厚45 μm、水含量0%时的外表面孔径0.267 4 μm，增加了约108.4%；同时，随着水含量从0%提升至7%，膜丝的内部从相对松散的海绵状孔结构趋于形成更加致密的海绵状孔结构，膜丝孔隙率从90.1%下降到79.9%，平均干燥收缩比从25.2%下降到16.3%，爆破压力从0.34 MPa升高至0.44 MPa。     

Accelerated photo-oxidation of polyethylene. II. Further evaluation of selected additives

A number of additives previously observed to promote photo-oxidative degradation of polyethylene films have been evaluated with respect to their relative photoinitiating effectiveness at wavelengths near 300 nm and their effects on thermal-oxidative stability of polyethylene. Depending on the nature of the additive, the photo-oxidation process may display autoretarding or autoaccelerating behavior. Thermomechanical analyses and gel content measurements on UV-exposed films containing substituted anthraquinones suggest that at short exposure times, photo-oxidative degradation is accompanied by photochemical crosslinking.     

PET纤维热老化的研究

测量了聚对苯二甲酸乙二醇酯(PET)纤维在不同温度下经不同时间热老化后的特性粘数、端羧基含量和断裂强度。PET纤维的特性粘数降和端羧基含量增长基本符合一级反应的规律。建立了PET纤维断裂强度变化的动力学方程,断裂强度随时间的变化为三级反应,断裂强度变化的表观活化能为135.7 kJ·mol-1。     

Photo-oxidation of phenoxy resin

A study has been made of the photolysis and photo-oxidation of phenoxy resin. Photolysis results in the evolution of hydrogen, methane, ethane, propene, propane, toluene, and the oxides of carbon. Also observed are increased yellowing, a rapid rise in gel content, and a decrease in intrinsic viscosity and elongation. Photo-oxidation causes similar changes, but produces oxidized chain fragments, more gel, and less yellowing as well as broad absorptions in the hydroxyl and carbonyl regions of the infrared spectrum. A free-radical mechanism is proposed in which both chain scission and crosslinking occur.     

The kinetics and mechanism of polyethylene photo-oxidation

The kinetics of the natural and accelerated photo-oxidation of low-denisty polyethylene (LDPE) films have been studied; different geographical locations have been selected for the natural tests, and a range of temperatures used in the accelerated experiments in a specially built temperature-controlled ultraviolet radiation enclosure. A meaningful correlation between natural and accelerated weathering results was established, by means of an adequate superposition of the effects of UV radiation exposure and temperature. Reasonably detailed and accurate, lumped-parameter, kinetic models of the photo-oxidation process have also been developed, to interpret and predict the results of measurements of carbonyl, hydroperoxide and vinyl absorbances as functions of time and temperature; the models predict the general experimental behaviour, and also that both the formation of hydroperoxides and carbonyl Norrish-I reactions are important initiation steps. More complex models have the potential of interpreting other fine details of the degradation behaviour, namely the generation of other chemical species, and the chain scission and cross-linking process which are directly related to changes in the mechanical properties.     

Effect of ferric salt of orange peel solid fraction on photo-oxidation and biodegradability of LDPE films

The present study is concerned with accelerating photo-oxidation and biodegradability of low-density polyethylene (LDPE) film in the presence of orange peel solid fraction (OPS), especially its ferric salt (OPSFe). Orange peel was made free from essential oils and pigments and then turned into a fine powder. The rate of photo-oxidative degradation of pure LDPE film and the blend samples, containing OPS/OPSFe at 0?C5?wt% in combination with PE-g-MA as a compatibilizer at 1?wt% of LDPE, in exposure to artificial sunlight was monitored by determination of carbonyl index derived from FTIR spectroscopy and the variations in mechanical properties in terms of UV-irradiation time. The original and irradiated samples (300?h) were buried in agricultural soil simultaneously and their biodegradation was evaluated by weight loss measurement, optical microscopy, and also calculation of carbonyl index derived from FTIR spectroscopy. The results obtained revealed that OPSFe acts as a significant accelerator in photo-oxidation and subsequent biodegradation of LDPE in soil enviornment. It is concluded that by incorporating small amount of Fe³⁺ ions into the polymer blend, photo-oxidative degradation of LDPE film is much more developed. Increase in OPSFe loading contributes to enhance the rate of photo- and biodegradability of LDPE films.     

Thermal degradation of polyethylene in a nitrogen atmosphere of low oxygen content. III. Structural changes occuring in low-density polyethylene at oxygen contents below 1.2%

Samples of low-density polyethylene, free from additives, were kept at temperatures between 284° and 355°C under nitrogen containing 1.16% oxygen or less. Changes in molecular weight distribution (MWD) and degree of long-chain branching (LCB) were followed by gel chromatography (GPC) and viscosity measurements. Other structural changes were investigated by infrared spectroscopy and differential scanning calorimetry (DSC). Both chain scission and molecular enlargement occur simultaneously. Chain scission accounts for the formation of low molecular weight material and volatiles. Molecular enlargement reactions cause an increase in LCB and ultimately the formation of insoluble material. At lower temperatures (284°C) an increase in the high molecular weight end of the MWD is observed. The amount of olefinic unsaturation, carbonyl, and ether groups increase with degradation. Conjugated systems are formed. The formation of thin discolored and insoluble surface layers indicate that the attack of oxygen is diffusion controlled. The DSC thermograms undergo large changes at 333° and 355°C, increasing with time and oxygen content. A reaction scheme for the thermo-oxidative degradation of polyethylene is discussed. Both inter- and intramolecular hydrogen abstractions by peroxy radicals are suggested to occur. Thus, the formation of trans-vinylene and ether groups results from intramolecular abstraction, while internal carbonyl groups are formed by intermolecular abstraction. Chain scission will be accomplished by both routes and together with “back-biting” is suggested to accoun for the formation of volatiles. The formation of conjugated sequences causing discoloration is correlated with the formation of trans-vinylene groups. Because of the restricted accessability of oxygen under our conditions, the reactions discussed previously for pure thermal degradation¹ are also considered to be important. The molecular enlargement observed is thus proposed to be mainly due to the combination of alkyl radicals even when oxygen is present.     

Thermal degradation of polyethylene in a nitrogen atmosphere of low oxygen content. III. Structural changes occurring in low-density polyethylene at oxygen contents below 1.2%

Samples of low-density polyethylene, free from additives, were kept at temperatures between 284° and 355°C under nitrogen containing 1.16% oxygen or less. Changes in molecular weight distribution (MWD) and degree of long-chain branching (LCB) were followed by gel chromatography (GPC) and viscosity measurements. Other structural changes were investigated by infrared spectroscopy and differential scanning calorimetry (DSC). Both chain scission and molecular enlargement occur simultaneously. Chain scission accounts for the formation of low molecular weight material and volatiles. Molecular enlargement reactions cause an increase in LCB and ultimately the formation of insoluble material. At lower temperatures (284°C) an increase in the high molecular weight end of the MWD is observed. The amount of olefinic unsaturation, carbonyl, and ether groups increase with degradation. Conjugated systems are formed. The formation of thin discolored and insoluble surface layers indicate that the attack of oxygen is diffusion controlled. The DSC thermograms undergo large changes at 3333° and 355°C, increasing with time and oxygen content. A reaction scheme for the thermo-oxidative degradation of polyethylene is discussed. Both inter- and intramolecular hydrogen abstractions by peroxy radicals are suggested to occur. Thus, the formation of trans-vinylene and ether groups results from intramolecular abstraction, while internal carbonyl groups are formed by intermolecular abstraction. Chain scission will be accomplished by both routes and together with “back-biting” is suggested to account for the formation of volatiles. The formation of conjugated sequences causing discoloration is correlated with the formation of trans-vinylene groups. Because of the restricted accessability of oxygen under our conditions, the reactions discussed previously for pure thermal degradation¹ are also considered to be important. The molecular enlargement observed is thus proposed to be mainly due to the combination of alkyl radicals even when oxygen is present.     

生物质水煤浆流变特性研究

以福建无烟煤、水葫芦、添加剂等制备生物质水煤浆,研究了其流变特性。结果表明：添加3％～3．5％的水葫芦及1％的分散剂制得的生物质水煤浆粘度在0．8～1．2Pa·s之间,且稳定性较好。生物质含量提高,生物质水煤浆的粘度逐渐上升;分散剂含量为1％时,能够制得流变性较佳的生物质水煤浆;搅拌强度的增加能够使生物质水煤浆的粘度降低;当温度低于60℃时生物质水煤浆的粘度随温度升高而下降;当温度高于60℃时,生物质水煤浆的粘度随温度升高而上升。     

The kinetics of photo-oxidation of low-density polyethylene films

The kinetics of the accelerated photo-oxidation of low-density polyethylene (LDPE) films has been studied within a range of temperatures, using an ultraviolet radiation enclosure. A simple, lumped parameter, kinetic model was developed to interpret the results of measurements of carbonyl and hydroperoxide absorbances as functions of time; the model predicts, with reasonable accuracy, the general experimental behavior and also that both the formation of hydroperoxides and carbonyl Norrish-I reactions are important initiation steps. Slightly more complex models may thus have the potential of interpreting other fine details of the degradation behavior, namely the generation of other chemical species and the chain scission and cross-linking processes, which are directly related to changes in the mechanical properties.     

FeSt_3对煤基聚乙烯薄膜光-热降解性能的影响

通过拉伸强度和断裂伸长率、TG以及FTIR的测试分析,研究硬脂酸铁(FeSt_3)含量不同的4种煤基聚乙烯薄膜在模拟自然先条件下的光.热降解性能.结果表明:光照时薄膜中添加的煤粉在FeSt_3作用下发生自由基反应,引发聚乙烯大分子断链,产生羰基;羰基指数随薄膜中FeSt_3含量的增加而增大,但薄膜力学性能相应降低,热稳定性则有所增强;聚乙烯大分子链结构在光照作用下发生脱羰基反应,断裂成小分子链;降解薄膜在光照72小时前处于衰变期,72小时后进入脆变期.