在振动磨中PVC的降解及与MMA共聚反应的研究

考察了温度、振幅、钢球直径等对ＰＶＣ在振动磨中降解的影响，确定ＰＶＣ力化学降解为无规断链过程。用力化学方法在振动磨中合成了ＭＭＡ－ＰＶＣ共聚物，通过ＩＲ和ＮＭＲ对ＭＭＡ－ＰＶＣ共聚物结构进行了鉴定，研究了ＰＶＣ／ＭＭＡ配比和振磨时间对共聚反应产率及共聚物组成的影响。热失重分析、ＳＥＭ观察和冲击强度测定结果表明，ＭＭＡ－ＰＶＣ共聚物比ＰＶＣ具有较高的热稳定性；ＭＭＡ－ＰＶＣ共聚物对ＰＶＣ／ＰＨＭＡ（聚甲基丙烯酸己酯）体系有增容作用     

超声波辐照下PVC的降解及与丙烯酸丁酯共聚反应的研究

研究了在超声波辐照下，聚氯乙烯（ＰＶＣ）在环己酮溶液中的降解及与丙烯酸丁酯（ＢＡ）的共聚反应。结果表明，ＰＶＣ在超声波辐照下可降解成低分子量产物，其分子结构与玻璃化温度基本未变。ＰＶＣ的超声降解符合一般力降解规律，降解动力学方程为（２１．５ｋＨｚ，３８０Ｗ，２５℃１．０％ＰＶＣ）ｌｎ＝１．５６×１０~（－４）ｔ。经ＩＲ、ＸＰＳ、ＮＭＲ等分析表明，ＰＶＣ与ＢＡ的超声共聚产物主要为嵌段共聚物。所得共聚物可以明显提高ＰＶＣ的冲击强度。     

振磨降解制得的低分子量PVC对PVC增塑作用的研究

通过振靡降解制得了低分子量聚氯乙烯（ＰＶＣ）。通过Ｂｒａｂｅｎｄｅｒ塑化仪和力学性能测试研究了振磨降解制得的低分子量ＰＶＣ对高分子量ＰＶＣ的增塑作用和力学性能的影响，提出了增塑机理。实验结果表明，振靡降解制得的低分子量ＰＶＣ能增塑ＰＶＣ，显著改善ＰＶＣ的加工性能，提高ＰＶＣ的力学性能。     

挤压铸造短纤维增强金属基复合材料浸渗过程分析

在分析挤压铸造金属基复合材料浸渗条件的基础上，建立了液态金属在短纤维预制件中的浸渗和压力分布模型，计算结果表明：（１）当外加压力不足以使短纤维预制件产生变形之前，其浸渗距离和浸渍前端的压力分别为：Ｘｆ＝１－Ｆ／１－Ｖ＇ｆ∫＾ｔ０ｕｄｔ和Ｐｓ＝μｕ／Ｋ＇０·１－Ｆ／１－Ｖ＇ｆ∫＾ｔ０ｕｄｔ－４Ｖｆ０γｃｏｓθ／ｄｆ（１－Ｖｆ１０）（２）当外加压力使短纤维预制件产生变形之后，其浸渗距离和浸渗前端的压力     

双噁唑啉化合物对PBT的增粘作用

以２．２＇－双（２－唑啉）和双（２－唑啉基）苯作扩链剂，用焙融挤出的方法，对聚对苯二甲酸丁二酯（ＰＢＴ）进行扩链，考察扩链剂的用量、反应时间和反应温度对ＰＢＴ的特性粘度及端羧基含量（ＣＶ）的影响。结果表明，当用２，２＇－双（２－唑啉）作扩链剂时，ＰＢＴ的特性粘度［η］从０．７９９提高到０．９２６ｄＬ／ｇ，ＣＶ降至５ｅｑ／１０￣６ｇ以下；当用双（２－　唑啉基）苯作扩链剂，［η］从０．７６３增至０．９２５ｄＬ／ｇ，ＣＶ降至１０ｅｑ／１０￣６ｇ以下，达到了较满意的扩链效果。     

在高速气流粉碎作用下PVC的力化学降解及形态变化的研究

通过ＧＰＴ、ＦＴ－ＩＲ、ＳＥＭ和力学性能测试，研究了在高速气流作用下聚氯乙烯（ＰＶＣ）的力化学降解反应、颗粒形态和微晶结构变化及其对ＰＶＣ物理、力学性能的影响。实验结果表明，经过高速气流处理ＰＶＣ，分子量将有所降低，晶体结构发生变化，颗粒尺寸和表观密度降低，比表面积增大，加工性能和力学性能得到明显改善。     

1,3-戊二烯阳离子聚合引发体系(CH3)3SiCl/EtAlCl2的研究

研究了阳离子引发体系Ｍｅ３ＳｉＣｌ（ＴＭＳＣｌ）ＥｔＡｌＣＬ２在正己烷中引发的１,３－戊二烯（ＰＤ）聚合反应。研究结果表明,在ＥｔＡｌＣｌ２引发的ＰＤ聚合反应中引入ＴＭＳＣｌ后大幅主提高了聚合物产率,同时使聚合反应速率明显提高,在「ＴＭＳＣｌ」／「ＥｔＡｌＣｌ２２」＝０－１范围内,ＴＭＳＣｌ／ＥｔＡｌＣｌ２体系制备的聚合物分子量高于ＥｔＡｌＣｌ２引发制备的聚合物,这些结果表明Ｍｅ３ＳｉＣｌ／ＥｔＡ     

用微波等离子体CVD制备C3N4薄膜

采用微波等离子体化学气相沉积法（ＭＰＣＶＤ）,使用高纯Ｎ２（９９．９９９％）和ＣＨ４（９９．９％）作反应气体,在多晶Ｐｔ（９９．９９％）基片上沉积Ｃ３Ｎ４薄膜。Ｘ射线能谱（ＥＤＸ）分析结果表明Ｎ／Ｃ原子比为１．０～１．４,接近Ｃ３Ｎ４的化学比;Ｘ射线衍射谱（ＸＲＤ）说明薄膜主要由β－和α－Ｃ３Ｎ４组成;Ｘ射线光电子谱（ＸＰＳ）、傅立叶变换红外谱（ＦＴ－ＩＲ）和喇曼（Ｒａｍａｎ）谱说明在Ｃ３Ｎ４薄膜     

氯化聚乙烯及其接枝氯乙烯悬浮液粘度的研究

本文采用搅拌法测量氯化聚乙烯（ＣＰＥ）及氯化聚乙烯（ＣＰＥ）接枝（－ｇ－）氯乙烯（ＶＣ）悬浮液的粘度，与含固率建立关系，用Ｍｏｏｎｅｙ和Ｒｏｂｉｎｓｏｎ方程式进行关联。由悬浮液表观粘度ηａ与含固率ψｖ的关系曲线得出临界含固率ψｃ，结果发现ψｃ与悬浮液沉降层体积Ｖｐ呈线性关系：ＣＰＥ：ψｃ＝－０．４５５Ｖｐ＋１．４５６；ＣＰＥ－ｇ－ＶＣ：ψｃ＝－０．１８６Ｖｐ＋０．７５２     

DBM-g-PE与PVC的相互作用研究EI

采用固相接枝法制备了ＤＢＭ－ｇ－ＰＥ，用红外光谱分析证明了接枝物确实存在。ＰＶＣ／ＣＰＥ＝１００／５合金性能测定结果表明，添加５份接枝物的合金（Ａ），缺口冲击强度、拉伸强度分别为１８．２ｋＪ／ｍ２和５３．０ＭＰａ；而添加５份ＰＥ的合金（Ｂ），其相应性能为５．１ｋＪ／ｍ２和３３．８ＭＰａ。不加接枝物的合金（Ｃ），虽有高韧性，但拉伸强度却由５３．０ＭＰａ降至５０．２ＭＰａ。ＤＳＣ、ＳＥＭ的结果均表明，ＰＥ接枝ＤＢＭ后与ＰＶＣ的相互作用增强，与ＣＰＥ协同作用能增韧、增强ＰＶＣ，并探讨了其机理。     

聚苯乙烯在应力作用下的降解动力学及降解机理研究

了聚苯乙烯在振动磨中的力降解动力学和降解机理，对Ｂａｒａｍｂｏｉｍ所推导的聚合物力降解动力学方程进行了修正。修正方程可更准确地描述本乙烯在振动磨中降解时的分子量变化过程。实验结果表明，聚苯乙烯在振动磨中的降解机理依赖于聚苯乙烯所受的应力强度。当应力强度较不时的聚苯乙烯的降解机理是人规断链过程；在应力强度较大时，聚苯乙烯的降解机理则是分子链多和同时发生断裂的一个非无规断链过程。     

分子结构对增塑聚氯乙烯性能的影响

研究了聚合度、分子量分布和支化结构对增塑聚氯乙烯加工流变性能和物理力学性能的影响。结果表明，增塑ＰＶＣ的加工流变性能随聚合度的增加而恶化；拓宽分子量分布和引入支化结构均有利于加工流变性能的提高；增塑ＰＶＣ的拉伸强度随聚合度的增加而提高，而压缩永久变形却随之减小；分子量分布对物理力学性能的影响不大；支化ＰＶＣ的拉伸强度略有下降。     

Mechanical and swelling properties of thermoplastic elastomer blends

The mechanical behavior, microhardness and abrasion resistance of acrylonitrile butadiene rubber (NBR) vulcanizate loaded with 40 phr fast extrusion furnace (FEF) carbon black nanopowder and different concentrations of suspension polymerization polyvinyl chloride (PVC) were studied. The measured parameters (i.e., the Young’s modulus, tensile strength, and elongation at break) varied with the concentration of PVC. Both the elastic modulus and the tensile strength increased with increasing PVC loadings while the elongation at brake recorded a linear decrease. The hardness degree and the abraded mass increased as the concentration of PVC increased. The classical theory of rubber elasticity was used to calculate the rubbery modulus, the number of effective chains per unit volume and the average molecular weight. Swelling measurements were done on the mentioned samples. Addition of PVC was found to decrease the maximum degree of swelling, the penetration rate and the average diffusion coefficient. Swelling was found to slightly affect the degree of hardness and elastic modulus.     

MBS树脂相相对分子量变化对PVC/MBS力学性能的影响

通过调控分子量合成了系列树脂相相对分子量变化的MBS树脂.将其与PVC树脂进行熔融共混,并测试PVC/MBS合金的力学性能.测试结果表明,分子量转移剂TDDM用量越多,MBS树脂相的相对分子量越低,PVC/MBS合金熔体流动速率越高、加工流动性越好、冲击强度越高,但对拉伸强度影响不大.这对开发系列MBS树脂具有重要指导意义。     

Fabrication and characterization of porous calcium polyphosphate scaffolds

Porous calcium polyphosphate (CPP) scaffolds with different polymerization degree and crystalline phases were prepared, and then analyzed by scanning electron microscopy (SEM), Thermmogravimetry (TG) and X-ray diffraction (XRD). Number average polymerization degree was calculated by analyzing the calcining process of raw material Ca(H₂PO₄)₂, as a polycondensation reaction. Amorphous CPP were prepared by the quenching from the melt of Ca(H₂PO₄)₂ after calcining, and CPP with different polymerization degree was prepared by controlling the calcining time. Meanwhile, CPP with the same polymerization degree was prepared to amorphous or different crystalline phases CPP which was made from crystallization of amorphous CPP. In vitro degradation studies using 0.1 M of tris-buffered solution were performed to assess the effect of polymerization degree or crystalline phases on mechanical properties and weight loss of the samples. With the increase of polymerization degree, the weight loss during the degradation decreased, contrarily the strength of CPP increased. The degradation velocity of amorphous CPP, α-CPP, β-CPP and γ-CPP with the same polymerization degree decreased in turn at the same period. The full weight loss period of CPP can be controlled between 17 days and more than 1 year. The results of this study suggest that CPP ceramics have potential applications for bone tissue engineering.     

Highly permeable membrane prepared by phase inversion of mechanochemically modified polyvinylchloride

Polyvinylchloride (PVC) powders containing (or not) calcium carbonate were mechanochemically modified using a ball mill. Membranes prepared by phase inversion of the modified PVC were tested by scanning electron microscopy, infrared spectroscopy, thermogravimetry, and differential scanning calorimetry to compare the structure and properties before and after mechanochemical modification. The results showed that after mechanochemical modification, pure water flux of the phase inversion PVC membrane reached up to 378.6 L/(m² h), significantly higher than that before modification [123.3 L/(m² h)]; calcium carbonate enhanced the dechlorination effect of mechanochemical modification and further increased pure water flux of the membrane to 454.2 L/(m² h). Mechanochemical modification increased the tensile strength of the PVC membrane by 4.1 % and decreased crystallinity of the PVC powder by about 34 %.     

结晶度对高密度聚乙烯热氧老化特性的影响

研究了结晶度对高密度聚乙烯(HDPE)在110℃人工热氧老化条件下老化特性的影响,分别采用力学实验、衰减全反射红外光谱技术、凝胶渗透色谱、扫描电子显微镜和X射线衍射技术比较了不同结晶度HDPE的热氧老化特性,研究了结晶度对聚乙烯力学性能、化学结构、相对分子质量、表面微观结构和晶体结构的影响规律。结果表明,结晶度越高,HDPE拉伸强度、拉伸模量和弯曲模量下降越快,抗冲击性能提高;不饱和度增长越剧烈,支化作用和断链作用更明显,羟基指数增长更快,且区别主要集中于老化后期;相对分子质量分布下降越快;表面微观形貌老化程度越严重;主要晶面衍射角和晶胞参数变化越显著。结晶度越高,HDPE缺陷也就越多,在热氧环境中越容易发生氧化,老化现象更严重。