本体和悬浮聚氯乙烯搪塑粉的熔融性能

采用热板实验和HAAKE流变实验，研究了聚氯乙烯搪塑粉的熔融致密厚度和熔融温度。结果发现，用本体聚合树脂制备得到的搪塑粉比悬浮聚合树脂制备得到的搪塑粉更易熔融，更适合搪塑工艺的需要；搪塑粉熔融性能与树脂颗粒粒径无关。本文还通过扫描电镜从形态角度对两类搪塑粉熔融性能的差异进行了分析探讨。     

Low-temperature crystallization of silicate dust in circumstellar disks.

Silicate dust in the interstellar medium is observed to be amorphous, yet silicate dust in comets and interplanetary dust particles is sometimes partially crystalline. The dust in disks that are thought to be forming planets around some young stars also appears to be partially crystalline. These observations suggest that as the dust goes from the precursor clouds to a planetary system, it must undergo some processing, but the nature and extent of this processing remain unknown. Here we report observations of highly crystalline silicate dust in the disks surrounding binary red-giant stars. The dust was created in amorphous form in the outer atmospheres of the red giants, and therefore must be processed in the disks to become crystalline. The temperatures in these disks are too low for the grains to anneal; therefore, some low-temperature process must be responsible. As the physical properties of the disks around young stars and red giants are similar, our results suggest that low-temperature crystallization of silicate grains also can occur in protoplanetary systems.     

聚氯乙烯的辐射交联

ＰＶＣ经交联后，其热性能、电性能、机械性能均大幅度提高，材料使用耐温等级亦相应提高．与传统的化学交联相比，采用高能电子射线进行的辐射交联方法具有产品质量好、生产工艺简单、生产效率高、能耗低、环境污染小等优点．文中综述了在多官能团单体交联剂存在下，以高能电子射线对ＰＶＣ进行辐射交联的基本原理、交联产品的性能及交联生产的工艺特点，比较了辐射交联与化学交联之间的优缺点，总结了近年来ＰＶＣ辐射交联技术在理论及工业应用中的最新进展，并介绍了辐射交联ＰＶＣ材料在电线电缆、建筑材料等领域的应用．     

PVC粉料的混合

研究了如何获得均一性更好的ＰＶＣ干混粉料，ＰＶＣＤ粉料在混合过程中押料量，加料顺序，混曙度等控制因素对ＰＶＣ粉料的影响，阐述了ＰＶＣ粉料混拿产量的因素。     

LQ型填充剂在PVC圆网涂覆制品中的应用

ＬＱ型填充剂是一种新型的塑料填充剂，将它用在ＰＶＣ圆网涂覆制品中，可部分替代ＰＶＣ树脂，达到保证产品质量，降低成本的目的。     

Detection of carbonates in dust shells around evolved stars.

Carbonates on large Solar System bodies like Earth and Mars (the latter represented by the meteorite ALH84001) form through the weathering of silicates in a watery (CO3)2- solution. The presence of carbonates in interplanetary dust particles and asteroids (again, represented by meteorites) is not completely understood, but has been attributed to aqueous alteration on a large parent body, which was subsequently shattered into smaller pieces. Despite efforts, the presence of carbonates outside the Solar System has hitherto not been established. Here we report the discovery of the carbonates calcite and dolomite in the dust shells of evolved stars, where the conditions are too primitive for the formation of large parent bodies with liquid water. These carbonates, therefore, are not formed by aqueous alteration, but perhaps through processes on the surfaces of dust or ice grains or gas phase condensation. The presence of carbonates which did not form by aqueous alteration suggests that some of the carbonates found in Solar System bodies no longer provide direct evidence that liquid water was present on large parent bodies early in the history of the Solar System.     

PVC材料与产品对环境影响及其废物管理

分析了PVC材料的生产过程、添加剂的使用情况以及PVC材料与产品的生命周期期间可能导致的各种环境问题,并提出了一些可行措施来减少PVC材料与产品对人体健康和环境的影响,并对各类方法进行了分析,对PVC材料与产品的生产和过程和PVC废物的管理提出了可行方法.     

PVC增塑糊塑化及其制品迁移机理的研究

采用IR、DLI(解偏振光)等技术手段,研究了PVC增塑糊的塑化机理及其制品中影响增塑剂迁移的因素.结果表明,不论PVC中的H-C-Cl基团是否处于晶态,其塑化过程的本质就是增塑剂中的CO与H-C-Cl基团不断形成氢键的过程,由此可解释不同增塑剂与PVC的作用强弱.决定PVC糊制品中增塑剂迁移的主要因素在于增塑剂分子的大小,即分子越大,迁移越小.增塑剂与PVC的相互作用及增塑剂中苯环对降低迁移也有一定的影响.     

G.SHDSL接口卡多PVC的设计与实现

G.SHDSL利用现有双绞线支持最大5.7Mbps的对称接入速率,可以解决现有DSL上下行速率不对称和传输距离近的缺点,满足双向对称的商用宽带需求。描述了在PPPOEOA协议模式下,通过硬件逻辑及软件设计,增加以太网私有协议头,用户端设备G.SHDSL接口卡实现配置条多条PVC的方式,详细阐述了其关键技术的设计与实现。验证结果表明本系统每条PVC均可承载流量,且能完全满足对称高速率的远距离传输要求。     

马来酸酐改善聚氯乙烯色泽的机理研究

聚氯乙烯(PVC)在加工过程中受热脱HCl逐步形成共轭多烯烃,往往导致PVC颜色加深.为了抑制PVC颜色的变化,引入马来酸酐(MAH),马来酸酐与共轭双键发生Diels-Alder加成反应,阻断了共轭多烯烃的增长,导致共轭双键的长度和共轭双键的数量减少,抑制了PVC颜色的加深.     

GPC法测定MBS／PVC共聚树脂中PVC相对分子质量及其分布

采用GPc(凝胶渗透色谱)测定了MBS/PVC共聚树脂中PVC的相对分子质量及其分布,考察了样品质量浓度在0.05～0.4 mg/L之间时质量浓度的变化对测定结果的影响,以及溶剂溶解时间对测定结果的影响.结果表明:随着质量浓度的增加,测得的相对分子质量逐渐减小,分布逐渐变宽;相同测定条件下,溶剂溶解时间越长,测得的相对分子质量越大.分布越窄.     

聚氯乙烯消雾型无滴膜的研制

本文阐述了消雾剂的消雾机理，确定了消雾剂的品种及用量，介绍了聚氯乙烯消雾型无滴膜的配方设计、生产工艺及其优于普通无滴膜的多项性能指标。