聚乙烯接枝马来酸酐／聚氯乙烯共混体系的研究

研究聚乙烯与马来酸酐单体接枝反应，探讨反应条件对接枝率的影响，通过红外光谱对接枝率结构进行表征；研究接枝物及聚氯乙烯含量对共混体系拉伸强度的影响规律，用扫描电子显微镜观察共混物中的界面形态。结果表明，低密度聚乙烯接枝马来酸酐／聚氯乙烯共混体系的相容性和力学性能均有较大提高，接枝率为10％左右，PVC含量为40%时，共混物的拉伸强度可达13．80MPa。     

接枝率对PVC/PA6-g-SMA共混物结构与性能的影响

采用熔融共混方法制备了聚氯乙烯（PVC）与不同接枝率苯乙烯-马来酸酐共聚物(SMA）接枝改性聚酰胺6（PA6-g-SMA）的共混物,研究了PA6-g-SMA接枝率对PVC/PA6-g-SMA共混物力学性能及凝聚态结构的影响。结果表明,接枝率越高,PA6-g-SMA与PVC的相容性越好,在PVC基体中能以更小的相畴均匀分散,对PVC的增韧增强作用越明显;当PA6-g-SMA的接枝率为5.12 %,添加量为15 ％（质量分数,下同）时,共混物的冲击强度为64.7 kJ/m2,拉伸强度为55 MPa。     

聚氯乙烯／聚丙烯酸钠增混体系研究

本文采用化学反应制备了ＰＶＣ接枝共聚物,用此作为高吸水性树脂聚丙烯酸钠（ＰＡＡＮａ）与聚氯乙烯体系的增混剂,研究了接枝共聚物组成,接枝率等因素对该体系力学性能的影响,实验结果表明,所合成的接枝共聚物能显著提高聚氯乙烯与聚丙烯酸钠的相容性;当共聚物接枝率约为２５％时,接枝共聚物组成ＭＭＡ∶ＡＡ为３０∶７０时增混效果最佳,共混物的拉伸强度及断裂伸长率达到最大值;接枝共聚物分子量越高,增混效果越好研究聚氯乙烯的化学反应,制备接枝共聚物,有望推出ＰＶＣ与其它高分子材料共混的增混剂。     

LDPE接枝MMA及与高岭土共混

本文研究在水介质中，以过氧化苯甲酰为引发剂，ＬＤＰＥ与ＭＭＡ的技枝共聚反应，并用它制备了与高岭土的共混物。探讨了单体用量，反应时间对接枝度的影响规律，用红外光谱验证了接枝物的存在，还探讨了接枝度及高岭土填充量对拉伸强度的影响。结果表明在接枝度为１５％，高岭土填充量为１０％时，体系具有较高的拉伸强度。     

SAN及MBS改性氯化聚氯乙烯的研究

研究了稳定体系、ＳＡＮ及ＭＢＳ对氯化聚氯乙烯共混物力学性能、耐热性及加工行为的影响。结果表明：采用钡／镉复合稳定体系可获得较好的综合性能；提高ＭＢＳ用量可以增加共混物的冲击强度和断裂伸长率，耐拉伸强度下降；ＳＡＮ用量增加，共混物的拉伸强度上升，而冲击强度和断裂伸长率下降，加入ＳＡＮ和ＭＢＳ。共混物的耐热性略有下降，但能改善共混物的辊上加工行为。     

MAH熔融接枝LDPE及其产物在PC／HDPE共混物中的应用研究

利用熔融接枝的方法对于马来酸酐（MAH）接枝低密度聚乙烯（LDPE）的反应规律进行了研究，并对接枝产物（LDPE－g-MAH)在聚碳酸酯／高密度聚乙烯（PC／HDPE）（80／20）共混物的影响进行了研究。探讨了MAH用量在1.25-10份，DCP用量为0.125-1份范围内接枝产物中接枝率和凝胶的变化规律。接枝产物在PC／HDPE（80／20）共混物应用结果表明，接枝率为0.8%的接枝产物对PC／HDPE（80／20）共混物的增容作用优于0.3%的接枝产物。PC／HDPE（80／20）共混物的断裂伸长率和冲击强度随着接枝产物的用量的增加而增大。而拉伸强度在接枝产物用量为1.2份时出现极大值。扫描电子显微镜观察表明LDPE－g-MAH能够有效改善PC／HDPE（80／20）共混物的相分散形态。     

吸氧EMA共混物的制备及性能研究

将乙烯-丙烯酸甲酯共聚物（EMA）与四氢化苯甲醇（CM）经溶液酯交换制备了四氢化苯甲氧基接枝EMA（EMA-g-CM），再将EMA-g-CM与紫外光引发剂、钴催化剂熔融共混制备了吸氧EMA共混物。研究了CM用量、吸氧反应对EMA-g-CM和吸氧EMA共混物的结构与性能的影响。结果表明：增加酯交换反应中CM用量可提高EMA-g-CM的接枝量和吸氧量，当MA：CM物质的量比中CM比例大于1．5，接枝量和吸氧量变化趋缓。但CM用量增加会降低吸氧EMA共混物的拉伸强度和断裂伸长率，经紫外光引发吸氧后，EMA—g-CM被氧化生成醇类化合物，使断裂伸长率大幅下降。     

EPDM增韧PET的研究

在引发剂过氧化二异丙苯(DCP)的作用下，通过添加少量界面增容剂苯乙烯(St)提高接枝率，使甲基丙烯酸缩水甘油酯(GMA)与(乙烯／丙烯／二烯)共聚物(EPDM)反应，得到接枝物EPDM—g—GMA，将EPDM—g—GMA与PET共混，以提高共混体系的冲击强度。探讨了不同含量的EPDM—g—GMA对共混体系力学性能的影响。结果表明，随着EPDM—g—GMA含量的增加，共混体系的缺口冲击强度显著提高，当其含量为50％时，材料的缺口冲击强度为344．9J／m，约为纯PET的12倍；拉伸强度、弯曲强度和弯曲弹性模量出现一定程度的下降；EPDM—g—GMA含量为20％～30％时．材料的综合力学性能较好。     

HIPS-g-PMMA的合成及其在HIPS/PVC共混体系中的增容作用

采用自由基引发的溶液聚合法合成了高抗冲聚苯乙烯接枝聚甲基丙烯酸甲酯(HIPS-g-PMMA)增容剂，考察了引发剂用量、反应温度及反应时间对增容剂的接枝率及支链摩尔质量的影响；同时对增容剂对HIPS／PVC共混体系的增容效果作了考察。结果表明：最佳反应条件是反应温度80℃，反应时间4h，引发剂用量以0．2～0．25g为宜；增容剂HIPS-g-PMMA对HIPS／PVC共混体系表现出较好的增容效果，共混物的拉伸强度、屈服强度及断裂伸长率明显增加，冲击强度增大，电镜照片显示两相界面变得更加模糊。     

聚氯乙烯增韧改性剂的合成及共混改性研究

采用传统的乳液接枝聚合方法合成了以交联聚丙烯酸酯弹性体为核，聚氯乙烯（PVC）直接为壳层的新型聚氯乙烯复合改性剂，用于通用聚氯乙烯的增韧改性。通过粒径分析仪、透射电镜、动态力学分析等手段对复合粒子及其共混改性PVC材料进行了表征与测试。结果表明复合粒子具有核壳结构，粒径分布较窄；动态力学分析显示；改性剂的加入有效地改善了改性剂与PVC基体问的相容性；当改性剂加入量为6％（核壳质量比为50／50）时，改性PVC材料的缺口冲击强度为纯PVC的5倍。     

Synthesis of amphiphilic graft copolymers of SBS with acrylamide and study of their properties

Graft copolymerization of SBS in the form of sodium ionomer with acrylamide in emulsion using benzoyl peroxide as initiator and sodium ionomer of maleated SBS as a self‐emulsifier, which can form a stable cyclohexane/water emulsion with AM without using any other emulsifier, was carried out. Factors affecting the graft copolymerization were studied. The grafting % can reach about 15%. Emulsifying properties of sodium ionomer of maleated SBS and the graft copolymer, as well as the compatibilizing effect of the graft copolymer in blending polyvinyl chloride (PVC) with SBS, were studied. The sodium ionomer of maleated SBS, the graft copolymers, and the blends were characterized with IR and DSC. The results showed that water absorbency and emulsifying volume increase obviously after graft copolymerization with AM. 0.2 g of the graft copolymer containing 14 wt % PAM grafts can emulsify a mixture of 30 mL toluene and 70 mL water completely. The graft copolymer can be used as an effective compatibilizer in the blending of PVC and SBS, more effective than the sodium ionomer of maleated SBS. Only 2 wt % of the copolymer based on the blend used in blending is enough to raise the tensile strength three times. The blends with weigh ratios of PVC/SBS at 3/7–4/6 in the presence of the graft copolymer behave as thermoplastic elastomers with a tensile strength of 14 MPa, an ultimate elongation of 750%, and a permanent set of 17%. Glass transition temperatures of the blend shifted inward in the presence of the graft copolymer. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1248–1253, 2005     

氯化锂对聚乙烯醇材料性能的影响

通过熔融共混挤出的方式,采用氯化锂(LiCl)对聚乙烯醇(PVA)进行改性,制备了PVA/LiCl复合材料,并运用傅里叶红外光谱法、差示扫描量热法和X射线衍射法等分析方法,研究了不同含量的LiCl对PVA的结晶行为和力学性能的影响。结果表明:LiCl中的Li+与PVA中的羟基产生络合作用,破坏了PVA中原有的氢键,降低了PVA分子链排列的规整性。随着LiCl含量的增加,复合材料的熔点、拉伸强度降低,断裂伸长率略微上升。     

The toughness and morphology of (chlorinated poly[vinyl chloride])/(methyl methacrylate‐butadiene‐styrene) blends

A series of methyl methacrylate‐butadiene‐styrene (MBS) graft copolymers were synthesized via seeded emulsion polymerization techniques by grafting styrene and methyl methacrylate on poly(butadiene‐co‐styrene) (SBR) particles. The chlorinated poly(vinyl chloride) (CPVC)/MBS blends were obtained by melting MBS graft copolymers with CPVC resin, and the effect of the core/shell ratio of MBS graft copolymer and SBR content of CPVC/MBS blends on the mechanical properties and morphology of CPVC/MBS blends was studied. The results showed that, with the increase in the core/shell ratio, the impact strength of the blend increased and then decreased. It was found that, when the core/shell ratio was 50/50, the impact strength was about 155 J/m, and the tensile strength evidently increased. The toughness of the CPVC/MBS blend was closely related to the SBR content of the blend, and with the increasing of SBR content of blend, the impact strength of the blend increased. The morphology of CPVC/MBS blends was observed via scanning electron microscopy. Scanning electron microscopy indicated that the toughness of CPVC/MBS blend was consistence with the dispersion of MBS graft copolymers in the CPVC matrix. J. VINYL ADDIT. TECHNOL., 22:501–505, 2016. © 2015 Society of Plastics Engineers     

PP-g-AM的制备及其应用

用熔融接枝方法制备了聚丙烯接枝丙烯酰胺（ＰＰ－ｇ－ＡＭ）,用经我谱、化学滴定方法对接枝物进行了定性和定量的表征,讨论了单体,引发剂用量、接枝温度、反应坚接枝率的影响,并将接枝物应用于成ＰＡ６共混。结果表明当ＣＤＰ用量为０．１５％、ＡＭ为６％、挤出机转速为４０ｒ／ｍｉｎ,可获得最佳的接枝率,经接枝改性的ＰＰ与ＰＡ６共混,其冲击强度明显提高。     

一种新型交联剂对ACR增韧PVC的影响

采用二甲基丙烯酸乙二醇酯（EGDMA）作为一种新型交联剂,以种子乳液聚合方法合成了一系列不同交联剂含量的丙烯酸酯类核壳增韧改性剂（ACR）,用于对聚氯乙烯（PVC）树脂的增韧改性研究。通过改变交联剂的含量,测试了ACR的交联度、接枝度、接枝效率和玻璃化转变温度（Tg）。研究了ACR/PVC共混物的力学性能与交联剂含量之间的关系。数据显示：当交联剂含量增加时,ACR的交联度、接枝度、接枝效率和玻璃化转变温度都得到了升高。当交联剂含量为0.4%,ACR/PVC的质量比为8/100时,ACR/PVC共混物发生了脆韧转变,冲击强度为1145J/m,是纯PVC的39倍。     

Natural rubber‐g‐methyl methacrylate/poly(methyl methacrylate) blends

The grafting of the methyl methacrylate (MMA) monomer onto natural rubber using potassium persulfate as an initiator was carried out by emulsion polymerization. The rubber macroradicals reacted with MMA to form graft copolymers. The morphology of grafted natural rubber (GNR) was determined by transmission electron microscopy and it was confirmed that the graft copolymerization was a surface‐controlled process. The effects of the initiator concentration, reaction temperature, monomer concentration, and reaction time on the monomer conversion and grafting efficiency were investigated. The grafting efficiency of the GNR was determined by a solvent‐extraction technique. The natural rubber‐g‐methyl methacrylate/poly(methyl methacrylate) (NR‐g‐MMA/PMMA) blends were prepared by a melt‐mixing system. The mechanical properties and the fracture behavior of GNR/PMMA blends were evaluated as a function of the graft copolymer composition and the blend ratio. The tensile strength, tear strength, and hardness increased with an increase in PMMA content. The tensile fracture surface examined by scanning electron microscopy disclosed that the graft copolymer acted as an interfacial agent and gave a good adhesion between the two phases of the compatibilized blend. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 428–439, 2001     

PB橡胶粒径对CPVC/PVC/ABS共混体系结构与性能的影响

采用乳液聚合技术合成了一系列不同PB橡胶粒径的ABS核壳改性剂,将其与CPVC、PVC共混,考察了CPVC/PVC/ABS共混物的结构与性能。动态力学分析表明：CPVC与PVC比例为90/10时,CPVC/PVC共混物部分相容,CPVC/PVC/ABS共混物也是部分相容;扫描电子显微镜分析其形态结构表明：共混物中ABS分散受PB橡胶粒径影响,PB橡胶粒径为113 nm的ABS在CPVC中分散最均匀。力学性能测试表明：随着PB橡胶粒径的增加,共混物的冲击强度先增大后减小,拉伸强度并无明显变化。