水相悬浮法制备氯化聚氯乙烯新工艺

采用水相悬浮法氯化的一种新工艺以大摩尔质量的SG3型国产聚氯乙烯(PVC)树脂为原料,制备高摩尔质量和高氯含量的氯化聚氯乙烯(CPVC)树脂,考察了工艺条件对CPVC摩尔质量和氯含量的影响。结果表明,氯化后产品CPVC的数均摩尔质量Mn和重均摩尔质量Mw值分别为93 174 g/mol和196 153 g/mol,分别大于PVC的88 487 g/mol和186 607 g/mol;在PVC与盐酸溶液固液比25%,反应温度60℃,1,2-二氯乙烷与PVC质量比0.5,偶氮二异丁腈和紫外光双引发,氯气流量0.4 L/min条件下,产品CPVC氯含量最高可达70.86%。该工艺下SG3型PVC树脂可成功氯化,氯化过程分子链没有发生断裂,氯化效率好,达到国外专用PVC树脂的氯化水平。     

高摩尔质量PPR的非等温结晶性能

在工业化聚丙烯装置上生产了高摩尔质量乙烯无规共聚聚丙烯(UHPPR1)，用差示扫描量热仪、广角X射线衍射仪和偏光显微镜研究了UHPPR1和常规摩尔质量PPR(PPR1)的非等温结晶行为、晶体结构和形态，并测试了力学性能。结果表明，UHPPR1的刚性和韧性均较PPR1好。高摩尔质量的分子链起到成核剂的作用，有较快的结晶速率和较高的结晶温度，球晶变小；另一方面，由于UHPPR1的摩尔质量分布宽，其低摩尔质量部分易于结晶，与PPR1有相近的结晶度。     

直接缩聚法合成聚乳酸的工艺改进

以D，L-乳酸为原料，采用优选催化剂、分步除水、连续通氮气、高真空缩合等工艺，直接缩聚合成了可完全生物降解的材料聚乳酸(PLA)。研究了催化剂的种类和用量、聚合温度、聚合时间、体系真空度、聚合工艺等对聚乳酸摩尔质量的影响。最佳条件为辛酸亚锡催化剂0．5份，聚合温度175℃，聚合时间12h，真空度30Pa。改进工艺后合成的聚乳酸无氧化、变色现象，产物的粘均摩尔质量(Mη)达到20800g／mol。     

用PE改进UHMPE流动性的研究

选用不同牌号的高密度聚乙烯(HDPE)和低密度聚乙烯(LDPE)作为超高摩尔质量聚乙烯(UHMWPE)的流动改性剂，通过对共混物流变转矩、熔体质量流动速率及力学性能的分析；探讨了配比对UHMWPE／PE共混物流动性的影响。结果表明：用中等摩尔质量的PE改善UHMWPE的加工流动性效果较好，流动性越好的中等摩尔质量PE对UHMWPE的流动性改善效果也越显著；但对共混物力学性能的不利影响也越大。     

高摩尔质量聚苯乙烯的合成及反应动力学研究

用阴离子聚合的方法合成了高摩尔质量的聚苯乙烯树脂,并对高摩尔质量聚苯乙烯的聚合反应动力学过程进行了研究。求得不同聚合温度下假一级表观增长反应速度常数kp″,并根据不同温度下的kp″求取了高摩尔质量聚苯乙烯聚合表观增长活化能。对影响偶联反应的因素进行了考察,并对合成的高摩尔质量聚苯乙烯产品进行分析表征。     

不饱和聚酯/聚氨酯弹性体共聚改性的研究

合成了数均摩尔质量为2000-13000g／mol的活性端基聚氨酯弹性体，并与不饱和聚酯树脂进行混合、共固化以改性不饱和聚酯树脂；测试了不饱和聚酯树脂／聚氮酯弹性体共聚物的物理机械性能、马丁耐热和收缩率，并探讨了增韧机理及低收缩机理。结果表明：不饱和聚酯树脂固化前，聚氨酯弹性体与不饱和聚酯树脂相容性好；树脂固化时，聚氨酯弹性体以一定粒径的胶粒析出，均匀分布在树脂中。MAPU弹性体能降低UPR的固化收缩率，MAPU摩尔质量越大，用量越多，对UPR的收缩率补偿越高；MAPU-2的总体改性效果最好，当用量为15％时，UPR的冲击强度可提高55％以上，且拉伸强度、弯曲强度以及马丁耐热温度的保持率也达60％以上。     

“象水一样流动”的功能聚合物CBT

全球新品CBT功能树脂具有大环寡聚酯结构（类PBT结构）。加热时，会变得象水一样，粘度极低；若加入催化剂并在适当的温度下，CBT会聚合成高摩尔质量的PBT树脂。CBT树脂由Cyclics公司制造。     

聚苯硫醚树脂的反应挤出扩链研究

为了提高聚苯硫醚(PPS)树脂的摩尔质量,从PPS分子端基结构出发,提出了对树脂进行扩链的研究思路。考察了扩链剂环氧树脂(EP)和二苯基甲烷二异氰酸酯(MDI)的扩链效果及对PPS树脂基础性能的影响规律。研究发现,EP的加入能显著地降低PPS的熔体质量流动速率,提高扩链PPS的拉伸强度和冲击强度。EP扩链PPS的拉伸强度提高了近20 MPa,冲击强度提高了1倍以上。MDI的加入也可使PPS发生扩链反应,使得PPS的熔体质量流动速率降低及冲击强度增加,但MDI扩链PPS的拉伸和弯曲性能并没有明显提升。相比MDI,EP是PPS的优选扩链剂。     

端乙烯基聚二甲基硅氧烷合成反应动力学的研究

以八甲基环四硅氧烷(D4)、四甲基四乙烯基环四硅氧烷为单体，端乙烯基硅油为封端剂，四甲基氢氧化铵[(CH3)4NOH]为催化剂，合成了端乙烯基聚二甲基硅氧烷(Vi—PDMs)和端乙烯基聚甲基乙烯基硅氧烷(Vi—PMVS)；并对其反应动力学进行了研究。结果表明，在以(CH3)4NOH为催化剂、D4和端乙烯基硅油为原料合成Vi-PDMS的反应中，110℃下反应速度较快，平均摩尔质量略低；在95℃和110℃下的单体转化率均为85％左右；产物的粘度与聚合物的数均摩尔质量的关系为lg17=4．351g-↑Mn-16．24。合成Vi—PMVS的反应在110℃时的反应动力学规律与Vi—PDMS基本一致，其摩尔质量随反应时间的延长出现更明显的峰值。     

聚酯的摩尔质量与机械性能研究——Ⅰ.动态力学性能

应用粘弹谱仪考察了不同摩尔质量的聚酯(PET、PBT、PBT/PET)的动态力学性能,结果表明摩尔质量增大将提高其模量,但亦导致结晶速度变慢,使测得的模量反而比摩尔质量较低的试样小.     

Rheological and morphological properties of thermal-aged poly(phenylene sulfide) resin

This paper discusses the morphological properties of thermal-aged poly(phenylene sulfide) (PPS) resin by Fourier-transform infrared spectroscopy (FT-IR) and solid-state ¹³C-NMR. Also included is a method of applying the dynamic melt viscoelastic properties to determine the molecular weight distribution of the PPS resin. For virgin PPS resin, two resonance peaks were detected by NMR magic angle spinning (MAS) and cross polarization (CP) studies. However, four additional peaks can be seen for heat-treated PPS resin, indicating that the aromatic ring in PPS resin was attacked by sulfur-containing species or by the aryl ether group. The two most important reactions are crosslinking and chain extension. However, the chain extension is predominant when PPS is heated in nitrogen. The results coincide with the phenomenon observed in FT-IR studies. The molecular weight distribution of thermal-aged PPS resin was determined from dynamic melt viscoelasticity data. Results show that the longer the preheated time the broader the molecular weight distribution. It indicates that crosslinking and chain-extension reaction may have occurred when PPS resin was heated in air.     

火焰喷涂改良型聚苯硫醚涂层研究

为了能将聚苯硫醚（ＰＰＳ）用于现场涂装，本文采用火焰喷涂法制得了改良型ＰＰＳ涂层，初步考察了不同类型，不同分子量的ＰＰＳ以及喷涂工艺对涂层性能的影响，结果表明，在一定的喷涂工艺条件下，中等分子量和高分子量的改良型ＰＰＳ比通用型ＰＰＳ涂层的成膜性，韧性和附着力都好。     

聚苯硫醚的差示扫描量热分析

通过 DSC法测定不同聚苯硫醚 (PPS)树脂的热性能。结果表明 ,不同 PPS树脂的玻璃化转变温度、最快结晶速率温度和熔融温度相近时 ,树脂的加工和纺制的纤维的性能与结晶性能有明显关系。PPS相对分子质量对结晶性能的影响很敏感。采用新的数据处理方法获得了整个可结晶温度区间的结晶动力学参数。     

Thermal analysis of poly(phenylene sulfide) polymers. I: Thermal characterization of PPS polymers of different molecular weights

Thermal properties of Fortron®

1 ®Registered trademark of Hoechst Celanese Corporation.

poly(phenylene sulfide) (PPS) polymers of different molecular weights were studied by DSC. Crystallization studies revealed that the ability of these polymers to crystallize decreases with increasing molecular weight. The Avrami equation poorly describes the isothermal crystallization of PPS. Lamellar crystallization was observed for the lowest molecular weight sample. For the other, higher molecular weight polymers the Avrami exponent is always between 2 and 3, suggesting development of distorted spherulites with heterogeneous nucleation. The temperature dependence of the solid and melt heat capacities have been determined. The solid specific heat capacity did not exhibit a molecular weight dependence. The heat capacity increase at the glass transition, T_g, has been calculated to be 28.1 J°C^?1 mole^?1. The equilibrium melting point of PPS has been estimated to be 348.5°C using the Hoffman–Weeks method. The T_g of PPS increases with molecular weight. The T_g of the highest molecular weight evaluated is 92.5°C. A DMA relaxation peak corresponding to the onset of the phenylene ring rotation occurs at ?92°C. Only the highest molecular weight could be quenched to a completely amorphous state.     

Overall Investigation of Poly (Phenylene Sulfide) from Synthesis and Process to Applications—A Review

Poly (phenylene sulfide) (PPS) is one kind of high‐performance polymer with high thermal stability that can be used widely in different industrial domains. However, according to an investigation of the literature, few reviews have comprehensively focused on the continuous development of PPS applications in the past decade. To meet this demand, this paper provides an overall investigation of PPS polymer and PPS‐based composites from synthesis and process to applications. Briefly, this paper introduces PPS materials according to the following topics. First, the molecular weight distribution and morphology of PPS, as well as their reinforced parts, are introduced. Afterward, the topic is focused on the synthesis, process, and blending of PPS. In the next part, this paper investigates the key points regarding PPS as a high‐performance polymer, focusing on the aspect of thermal behavior and mechanical properties. Finally, PPS composite applications are emphasized and overviewed from a wide range of aspects.     

Synthesis and characterization of poly(phenylene sulfide), poly(2-methylphenylene sulfide), and poly(2,6-dimethylphenylene sulfide)

A facile synthesis of poly(phenylene sulfide) (PPS), poly(2-methylphenylene sulfide) (PMPS), and poly(2,6-dimethylphenylene sulfide) (PDMPS) from the respective copper (I) bromothiophenoxides is described. Polymerization was effected in a 10:1 quinoline:pyridine mixture at atmospheric pressure and conditions optimized for the preparation of high-molecular-weight materials. The preparation of PPS in pyridine under pressure at 250°C has been investigated for comparative purposes. Yields and the properties of materials produced by solution polymerization are comparable to or better than those produced in the autoclave reaction. Properties have been investigated as a function of reaction time and molecular weight, and the deficiencies of the molecular-weight assessment methods are discussed. PMPS and PDMPS have been similarly studied and their properties evaluated. The use of heat of crystallization determinations for molecular-weight studies on PPS are described and critically evaluated.     

Plane strain fracture toughness of polyphenylene sulfide

The plane strain fracture toughness of polyphenylene sulfide (PPS), tested with different molecular structures such as linear PPS, heat-treated PPS, and branched PPS, was investigated over a wide range of melt viscosity and crystallinity and compared with other mechanical properties. The fracture toughness of linear PPS increased with increasing melt viscosity, and it reached the highest fracture toughness calculated from linear elastic fracture mechanics (LEFM) observed in this study. In this high melt viscosity region, the linear PPS specimen showed slow crack growth instead of brittle fracture. Although the tensile properties of heat-treated PPS and branched PPS are the same as those of linear PPS, the fracture toughness of linear PPS is superior. The fracture toughness is affected by the crystallinity of the specimen, and the effect of crystallinity on fracture toughness is smaller than that of melt viscosity and molecular structure.     

CPPS/PA1010/EMG合金的制备与性能表征

采用(乙烯/马来酸酐/甲基丙烯酸缩水甘油酯)三元共聚物(EMG)为增容剂,与PA1010和化学处理的PPS(CPPS)熔融共混制备了CPPS/PA1010/EMG合金。当EMG含量为9份时,制备的高刚性、高韧性合金在保持其它力学性能基本不变的情况下其冲击强度提高了4.5倍;并研究了该合金的熔融结晶行为和热降解行为。     

Hydrolytic Stability of Polyphenylene Sulfide/Polyarylate Blends

In the immiscible blends of poly(phenylene sulfide) (PPS) and polyarylate (PAR), absorbed moisture partitioned into each phase according to the equilibrium value of the homopolymers. The water diffusivity was observed to decrease with increasing PPS concentration and at >45%, when PPS became the major component in the skin region, the diffusivity was equal to that of neat PPS. The molecular weight of the PAR fraction was found to degrade linearly with time due to hydrolysis.     

国产聚苯硫醚基本性能研究

分析测定了ＰＰＳ基本性能指标，并研究指出流变，结晶，热解动力学与其分子结构的关系。流变分析表明，分子量是影响粘度，加工性的重要指标；当热历程不同时，结晶度，结晶形态会有变化，热解动力学结果表明，ＰＰＳ适合作耐高温材料。