助剂对聚氯乙烯辐照改性的影响

本文研究了代表性的增塑剂邻苯二甲酸二丁酯(DBP)、稳定剂硬脂酸铅及多官能团单体三羟甲基丙烷三丙烯酸酯(TMPTA)和季戊四醇四丙烯酸酯(PETA)对聚氯乙烯(PVC)γ辐照改性的影响,测试了不同配方的 PVC 于不同剂量辐照时的凝胶含量、力学性能、热失重性能。结果表明,DBP 和硬脂酸铅对 PVC 的辐照交联是有益的。多官能团单体 TMPTA 和 PETA 对 PVC 的辐射交联有很大的促进作用。加入多官能团单体的 PVC 经辐照后,其拉伸强度、耐热性能和增塑剂束缚性能大大改善。     

SBS/PE-LD共混物的强化辐射交联研究

研究了多官能团单体的用量、官能团数目以及辐射剂量对苯乙烯丁二烯共聚物（SBS）与低密度聚乙烯（PE-LD）共混物的强化辐射交联效应,测试了共混物的辐射交联程度、力学性能与形状记忆性能。结果表明,随辐射剂量的增加,SBS/PE-LD共混物的交联程度增加;多官能团单体的加入能够提高共混物的交联程度;相同辐射剂量时,官能团数目越多,交联程度越高;辐射剂量高于150 kGy时,多官能团单体的加入可以提高SBS/PE-LD共混物的拉伸强度;强化辐射交联SBS/PE LD共混物具有优异的形状记忆性能。     

多官能团单体对甲基乙烯基硅橡胶的辐射交联敏化效应

研究了在γ射线的作用下多官能团单体对甲基乙烯基硅橡胶(MVQ)的辐射交联敏化效应.结果表明,加入多官能团单体的MVQ经过辐射发生交联反应;四甘醇二甲基丙烯酸酯、三烯丙基异氰尿酸酯、三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)3种多官能团单体对MVQ的辐射交联具有明显的敏化作用,其中TMPTMA的敏化效果最好,其最佳用量为2份;加入TMPTMA或者加大辐射剂量,MVQ的损耗因子提高,玻璃化转变温度升高;当辐射剂量为40 kGy时,添加2份TMPTMA的MVQ的物理机械性能达到最佳.     

辐射交联高密度聚乙烯泡沫塑料交联度的研究

与化学交联方法相比辐射交联的高密度聚乙烯泡沫塑料有光滑、均一的表面,闭孔和树脂的内在性质赋予它良好的机械性能、耐冲击性、绝缘性。研究了加入AC发泡剂、EVA、多官能团单体(SR444)的辐射交联高密度聚乙烯泡沫塑料与交联度相关的性质。测试的参数包括辐射剂量、凝胶含量、泡孔尺寸。高密度聚乙烯树脂中在不同辐照剂量条件下加入5～10份发泡剂及多官能团单体,辐射剂量10～50kGy。在泡孔形成和生长阶段,交联度对于凝胶含量、泡孔结构都有重要影响。     

聚乙烯敏化辐射交联研究进展

本文综述了应用辐射敏化剂以促进聚乙烯的辐射交联的研究进展,对敏化剂在聚乙烯辐射交联中的作用,敏化剂尤其是多官能团单体的敏化辐射交联反应机理,以及聚乙烯的链结构,聚焦态结构与敏化辐射交联的关系进行了介绍。同时也简要地叙述了添加剂对聚乙烯敏化辐射交联的影响和聚乙烯共混体系的敏化辐射交联效应。     

聚乙烯敏化辐射交联研究进展

本文综述了应用辐射磁化剂以促进聚乙烯的辐射交联的研究进展，对敏化剂在聚乙烯辐射交联中的作用，敏化剂尤其是多官能团单体的敏化辐射交联反应机理，以及聚乙烯的链结构，聚集态结构与敏化辐射交联的关系进行了介绍，并简单地叙述了添加剂对聚乙烯敏化辐射交联的影响和聚乙烯共混体系的敏化辐射交联效应。     

多官能团单体对聚乙烯的增感辐致凝胶效应

研究了典型的多官能团单体三羟甲基丙烷三甲基丙烯酸酯（TMPTMA）对不同种类聚乙烯辐致凝胶效应的促进作用，实验表明：多官能团单体对聚乙烯早期的辐射交联有显著的促进作用，但随着剂量的增加，作用逐渐减弱直至消失，它对聚乙烯的极限凝胶分量几乎没有贡献，这种作用对聚乙烯的品种没有选择性，依据对实验事实的分析，多官能团单体对聚乙烯辐射交联的促进机理应是：辐射引发单体聚合，在聚合的同时向大分子链频繁发生链转移，从而形成大分五－单体聚合物之间的交联网络，由于更高的剂量率能够引发更多的聚合反应动力学链，所以有助于单体对交联促进作发挥。     

辐射增强PP/TAIC(TMPTMA)/PE共混体系相界面反应的研究——(Ⅰ)多官能团单体对形态结构及力学性能的影响

本研究中采用三烯丙基异腈脲酸酯(TAIC)和三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)为PP/PE共混体系的多官能团单体。研究了辐照剂量,多官能团单体种类和多官能团单体用量对共混物形态结构及力学性能的影响。发现TAIC及TMPTMA对PP/PE体系有较好的增容作用,共混物具有好的相容性,力学性能得到改善。     

聚合物辐射交联的强化技术探讨及其促进剂体系的研究进展

介绍了聚合物辐射交联的特点,探讨了聚合物辐射交联的强化技术,综述了多官能团单体强化聚合物辐射交联技术的研究进展.     

辐射引发界面反应改善PP/LDPE体系力学性能

利用辐射引发的界面反应来改善聚丙烯/低密度聚乙烯(PP/LDPE)共混体系的力学性能.研究了多官能团单体三聚异氰酸三烯丙酯(TAIC)、三羟甲基丙烷三甲基丙烯酸酯(TMPTMA)对PP/LDPE共混体系的相态结构、力学性能的影响.结果表明,引入多官能团单体后,PP,LDPE两相界面模糊,经过35 kGy的辐照,含有多官能团单体的共混体系的拉伸强度、拉伸断裂能、断裂伸长率均得到了大幅度提高.     

Shape‐memory behaviors of sensitizing radiation‐crosslinked polycaprolactone with polyfunctional poly(ester acrylate)

The sensitizing effects of polyfunctional poly(ester acrylate) on the radiation crosslinking of polycaprolactone (PCL) were studied. The influences of the use of the polyfunctional material, the number of functional groups, and the radiation dose on the radiation crosslinking, dynamic mechanical properties, and shape‐memory behaviors of PCL, respectively, were investigated. The radiation crosslinking of PCL, under the conditions in which the polyfunctional material was applied, did not follow the classic Charlesby–Pinner equation but instead followed the Chen–Liu–Tang relation. The efficiency of the radiation crosslinking of PCL was distinctly improved with the polyfunctional material. The greater the usage and functional group number were, the greater gel content and the more distinctive the radiation‐crosslinking effects were. This also indicated that the polyfunctional material directly participated in the crosslinking reaction. Dynamic mechanical analysis indicated that enhanced radiation crosslinking better raised the heat deformation temperature of PCL and presented a higher and wider rubbery‐state plateau; it also produced greater strength at temperatures higher than the melting temperature and provided greater force for recovering the deformation than pure PCL. The shape‐memory results revealed that sensitizing crosslinked PCL presented 100% recoverable deformation and a quicker recovery rate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 634–639, 2005     

The effect of peroxide crosslinking on thermal,mechanical, and rheological properties of polycaprolactone/epoxidized natural rubber blends

Polycaprolactone (PCL)/epoxidized natural rubber (ENR) blends (PCL/ENR = 70/30, 50/50 wt/wt) were prepared by a melt mixing in an internal mixer in the presence of a small amount (0.5 and 1 phr) of dicumyl peroxide. The effect of peroxide crosslinking on thermal, mechanical, and rheological properties of the blends was investigated by means of DSC, tensile test, and small amplitude oscillating rheometer, respectively. It was revealed that peroxide crosslinking enhanced degree of crystallinity of PCL phase and its non-isothermal melt crystallization temperature. The crosslinked blends behave like a thermoplastic elastomer exhibiting high elongation-at-break and fairly good elastic recovery as well as melt processibility. From melt rheological analysis, the peroxide crosslinked blends showed more pronounced shear thinning effect and higher elasticity compared to simple blends.     

Crystallization behavior and mechanical properties of poly(ε‐caprolactone)/cyclodextrin biodegradable composites

The poly(ε‐caprolactone) (PCL)/α‐cyclodextrin (α‐CD) inclusion complex (PCLIC) was successfully prepared, and its effect on the thermal behavior and mechanical properties of PCL was thoroughly studied. It is shown that the addition of PCLIC greatly increased the crystallization rate and thermal stability of the PCL. The Young's modulus and yield strength of PCL/PCLIC composite are about 2 and 1.3 times of the pure PCL, and the elongation at break of the PCL/PCLIC composites kept above 350%, when the PCLIC composition is 15 wt %. It is shown that PCLIC is a good enforcing biofiller for the PCL. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

过氧化物交联聚烯烃弹性体的性能

采用过氧化物交联，讨论了交联剂、共交联剂、补强填充剂以及增地采用茂金属催化剂合成的乙烯－辛烯共聚物（ＰＯＥ）的物理机械性能的影响。和过氧化物交联后，ＰＯＥ的拉伸强度、扯断伸长率和扯断永久变形大幅度下降。加入共交联剂，可以提高交联程度，缩短硫化时间。加入炭黑，可以起到补强作用。提高１００％定伸应力、撕裂强度、伸强度和硬度，减小扯断伸长率和扯断永久变形。加入增塑剂降低了某些力学性能，但扯断伸长率增加，     

纳米羟基磷灰石增强聚己内酯/明胶纤维膜的制备及其性能

引导组织再生膜在引导组织再生术中发挥着关键作用,高性能的引导组织再生膜能更好地促进组织再生修复。本文以纳米羟基磷灰石（n-HA）、聚己内酯（PCL）、明胶（Gel）为原料,通过静电纺丝法制备了不同含量n-HA增强的PCL/Gel/n-HA纤维膜,并对其形貌、组成、力学性能及降解性能进行了研究。SEM结果表明,纤维膜中的纤维形态良好,纤维直径大致分布于200～400nm之间,交联后纤维直径明显增加;TEM结果表明,n-HA较均匀分散在纤维中,随着n-HA含量的增加,n-HA在纤维膜表面发生聚集。力学测试结果表明,随着n-HA含量的增加显著提高了纤维膜的拉伸强度和断裂伸长率,当n-HA含量约为15%时,其拉伸强度和伸长率分别达到9.18MPa和180%。n-HA加入后,纤维膜的降解速率明显降低,n-HA含量约为15%的复合纤维膜体外降解12周以后约降解25%。本文制备的PCL/Gel/n-HA纤维膜的力学性能和降解速率能满足临床对引导组织再生膜的性能要求。     

电子束辐照对聚对苯二甲酸丁二醇酯的影响

采用电子加速器对聚对苯二甲酸丁二醇酯(PBT)进行辐照,研究了吸收剂量、交联助剂及辐照气氛对PBT凝胶含量的影响,以及辐照交联对PBT力学性能及结晶行为的影响。结果表明,PBT树脂对电子束辐照相对稳定,交联助剂TMPTA能有效促进PBT的辐照交联;辐照后的PBT拉伸强度较未辐照时明显提高,断裂伸长率相应地略有降低;而同一吸收剂量下,交联助剂的添加量对PBT的拉伸强度及断裂伸长率无明显影响;PBT辐照交联后熔点降低,熔融焓减小,形成尺寸较小、结构不完善的晶体。     

Crystallization,mechanical properties,and enzymatic degradation of biodegradable poly(ε‐caprolactone) composites with poly(lactic acid) fibers

Biodegradable polymer composites based on poly(ɛ‐caprolactone) (PCL) and poly(lactic acid) (PLA) fibers were prepared by melt compounding. The effects of PLA fibers on the crystallization, mechanical properties, and enzymatic degradation of PCL composites were investigated. The addition of PLA fibers enhanced the crystallization of PCL due to the heterogeneous nucleation effect of fibers. However, the final crystallinity of the PCL in the composites was little changed in the presence of PLA fibers. With the addition of PLA fibers, significant improvement in storage modulus (E′) of PCL in the composites was achieved. A significant increase in E′ was 173% for the composites as compared to that of the neat PCL at 20°C. With the increase in PLA fibers content, the PCL composites showed decreased elongation and strength at break; however, the tensile yield strength and modulus were increased significantly, indicating that PCL was obviously reinforced by adding PLA fibers. Although the PLA fibers retarded the enzymatic degradation of PCL, it was possible to be completely degraded without much degradation time for PCL blending with suitable amounts of PLA fibers. POLYM. COMPOS., 34:1745–1752, 2013. © 2013 Society of Plastics Engineers     

舰船用辐射交联无卤阻燃电缆护套料的研究

应用γ射线辐射交联技术,制备出以乙烯－醋酸乙烯/茂金属聚烯烃弹性体/纳米级改性氢氧化铝（EVA/POE/ ATH）为基材的舰船用无卤阻燃电缆护套料,探讨了共混物配比、ATH的种类与用量以及辐射剂量对材料力学性能和阻燃性能的影响。结果表明,随着POE用量的增加,材料的拉伸强度和断裂伸长率增加,耐热老化性能提高,但硬度降低;纳米ATH的加入使材料具有较好的阻燃性能;材料的辐射交联工艺可弥补阻燃剂对材料力学性能的影响,在辐射剂量为80 kGy的条件下,采用EVA /POE/ATH ＝90/10/60（质量份数,下同）的共混体系可制备出综合性能优异的护套料。     

PLA/PCL/滑石粉复合材料的制备与性能

在聚乳酸(PLA)中添加不同含量的聚己内酯(PCL)和滑石粉,同时添加增容剂柠檬酸三丁酯(TBC),通过熔融共混制备一系列PLA/PCL/滑石粉复合材料。主要研究了PCL、滑石粉以及TBC对PLA力学性能和结晶性能的影响。结果表明,PCL提高了PLA的韧性,但降低了强度,滑石粉主要起到了增强作用,但降低了PLA韧性,而将两者共同添加到PLA中可以起到一定的增强增韧作用,其异相成核作用也提高了PLA的结晶度。增容剂TBC的加入,改善了PLA和PCL的相容性,提高PCL的增韧效果以及复合材料的结晶度,但略微降低了PLA的拉伸强度。当PCL和滑石粉质量分数均为10%且加入0.5份的TBC后,PLA/PCL/滑石粉复合材料的断裂伸长率、拉伸强度、结晶度分别为13.3%,61.6 MPa,43.0%,相比纯PLA分别提高了533%,2%,73.4%。     

PTFE的辐射交联及其应用

利用电子束高温辐照PTFE,制备出交联PTFE样。通过红外光谱法（IR）、差示扫描量热分析法（DSC）等各种方法研究辐射交联PTFE的性能。结果表明：与未辐照PTFE相比,交联PTFE的透明度明显增加,熔点下降,耐磨性能明显提高。