LDPE/iPB共混物的性能

采用传统共混方法制备了低密度聚乙烯(LDPE)/全同聚1-丁烯(iPB)共混物,测定了力学性能和热性能。通过偏光显微镜观察和差示扫描量热法等研究了LDPE/iPB体系的结晶行为。结果表明:随着w(LDPE)的增加,共混体系的拉伸强度和弯曲强度出现最小值,热性能下降,结晶变得不完善,LDPE/iPB共混物的相容性较差。     

利用ISBS分散纳米P(MMA-St)对聚丙烯增强增韧改性研究

将0.5%~4.0%的P(MMA-St)粉体作为改性剂加入到聚丙烯(PP)中,利用原位气泡拉伸法(ISBS)进行纳米分散。采用力学性能和SEM研究了共聚物粉体用量对PP拉伸强度、冲击强度及弯曲强度的影响。结果表明：利用ISBS方法,可以将P(MMA-St)很好地分散到PP中,P(MMA-St)的加入提高了PP/P(MMA-St)共混物的力学性能,其中拉伸强度提高了7.50 %,缺口冲击强度提高了103.77 %。利用XRD对共混物的结晶形态和行为进行了研究,结果表明纳米共聚物粉体的加入可以诱导β晶型的产生,使得共混物的韧性提高。     

E-MA-GMA增容剂对PPS/PA66共混体系性能的影响

研究了增容剂乙烯(E)-丙烯酸酯(MA)-甲基丙烯酸缩水甘油酯(GMA)共聚物(E-MA-GMA)对聚苯硫醚(PPS)/聚酰胺(PA)66共混体系的相容性、力学性能、热性能、流变性能的影响。结果表明,增容剂的加入,增加了共混体系的相容性,提高了共混物的力学性能;DSC结果表明,E-MA-GMA影响共混体系的结晶和熔融行为;流变性能测试结果表明,增容PPS/PA66共混体系是假塑性流体,E-MA-GMA用量增加,使共混体系的表观黏度增大。     

PVF2／P（MM—St）共混体系的结晶性能和相容性的研究

用示差量热法（ＤＳＣ）、动态力学分析法（ＤＭＡ）和悬浮法测密度法研究了聚偏氟乙烯（ＰＶＦ２）／甲基丙烯酸甲酯与苯乙烯的无规共聚和［Ｐ（ＭＭＡ－Ｓｔ）］的共混体系的相容性和结晶性能。结果发现ＰＶＦ２／Ｐ（ＭＭＡ－Ｓｔ）共混体系是部分相容体系,其结晶性能随共混物中Ｐ（ＭＭＡ－Ｓｔ）的含量而变化,并就模压成型的热历史对该共混体系相容性的影响进行了讨论。     

PHBV/PCL共混纤维的结构与性能

采用熔融纺丝法制备聚羟基丁酸戊酸酯(PHBV)/聚ε-己内酯(PCL)生物可降解共混纤维。采用差示扫描量热仪、广角X射线衍射仪、热台偏光显微镜和傅立叶变换红外光谱仪对PHBV/PCL共混体系的相容性和结晶性能进行了表征。结果表明:PHBV和PCL是不相容的;PHBV/PCL共混体系中的PHBV影响了PCL的结晶机制和结晶速率,PCL的结晶形态没有改变;PCL不影响PHBV的结晶机制,降低了PHBV的结晶速率,改变了PHBV的结晶形态。     

受阻酚改性聚酯/聚醚胺型PU/P(MMA-St)IPN阻尼性能的研究

用一步法制备了受阻酚AO-80改性的聚酯/聚醚胺型聚氨酯/聚(甲基丙烯酸甲酯-苯乙烯)互穿聚合物网络(PU/P(MMA-St)IPN)。通过热失重分析仪、动态力学分析以及扫描电子显微镜对IPN材料的热稳定性、阻尼性能和微观结构形态进行了表征。研究结果表明:AO-80可以提高PU与P(MMA-St)的相容性,从而有效拓宽阻尼温域;当聚氨酯中聚酯/聚醚胺=80/20,w(AO-80)=20phr,PU/P(MMA-St)=70/30时,所得IPN材料的阻尼性能最佳。     

PP/EVOH共混物结构与性能研究

采用丙烯酸接枝聚丙烯（PP-g-AA）、衣康酸接枝聚丙烯 (PP-g-ITA)、马来酸酐接枝聚丙烯 (PP-g-MAH)3种相容剂增容聚丙烯（PP）/乙烯-乙烯醇共聚物(EVOH)共混体系,研究了共混体系的相容性、热性能、力学性能和阻隔性能。红外光谱分析表明,相容性的改善源于相容剂与EVOH之间形成的酯键和氢键。扫描电镜显示,PP-g-AA、PP-g-ITA、PP-g-MAH的增容作用依次增强,共混体系中相容剂增容作用越强,分散相尺寸越小,界面结合越牢固。差示扫描量热分析发现,PP/EVOH增容共混体系中EVOH组分的结晶温度低于不含相容剂的共混体系EVOH组分的结晶温度,PP组分的结晶温度变化则相反。增容共混体系与不含相容剂的共混体系相比,拉伸强度提高了10 MPa,吸油率降幅达0.8 %。     

NC/PEG共混体系的相容性研究

采用差示扫描量热法(DSC)和动态力学分析法(DMA)研究了不同质量比的硝化棉/聚乙二醇(NC/PEG)共混体系的相容性。结果表明,NC/PEG共混体系中PEG的熔点、结晶度和结晶熵随NC含量的增加明显降低,共混组分相互作用参数χ1,2为负值,即共混体系在热力学上具有相容性。共混体系的玻璃化转变温度随NC含量的增加均向低温移动,并且当共混体系中NC与PEG质量比为1∶1时,共混体系呈现单一的玻璃化转变温度。     

丁腈橡胶/聚氧乙烯共混体系对聚氧乙烯结晶性能的影响

通过溶剂浇注法制备了丁腈橡胶/聚氧乙烯(NBR/PEO)共混物,通过接触角测试、傅里叶变换红外光谱分析和差示扫描量热分析,研究了NBR和PEO相互作用对PEO结晶性能的影响。结果表明,NBR/PEO共混物的表面能和附着功分别为8.80 mJ/m2和56.90 mJ/m2,两者之间具有一定的相容性;NBR中的腈基和PEO中的醚基之间并没有相互作用,两者之间具有一定的相容性,是由非极性部分贡献;NBR/PEO共混体系中随着PEO含量的减少,PEO分子链采取旁式构象的结晶结构增多,并使PEO的结晶度和结晶熔融温度明显降低,在PEO含量为5份时,NBR/PEO共混体系中PEO结晶度和结晶熔融温度分别下降80%和10.5℃,NBR的加入明显抑制了PEO的结晶。     

EVOH／PE-HD共混相容性研究

使用三种功能化改性的聚乙烯作为相容剂改善EVOH／PE-HD共混体系的相容性，研究了共混体系的热性能和力学性能。SEM表明，相容共混体系中形成了高度分散和牢固的界面结合，二甲苯萃取实验和IR分析证实了相容性的改善来自于EVOH与相容剂之间的化学反应。相容共混体系中EVOH作为分散相时其结晶温度明显降低，结晶速度放慢；共混物中两组分的结晶熔点均低于纯组分。这些均可归因于体系更好的相容性以及强烈的界面作用。相容共混体系的力学性能较之简单共混体系得到明显改善，EVOH为分散相时拉伸强度提高幅度较大(50％)，而在PE-HD为分散相时缺口冲击强度的增幅达到30％。     

The crystalline phase transformation of poly(vinylidene fluoride)/poly(vinyl fluoride) blend films

Poly(vinylidene fluoride) (PVDF), poly(vinyl fluoride) (PVF), and their blends were prepared by solution casting, followed by quenching in ice water after melting to obtain an α-crystalline phase. The films were drawn by solid state extrusion at two different drawing temperatures, 50°C and 110°C. The crystalline phases were analyzed by DSC and FTIR. In the undrawn films, the content of β-crystalline phase in the blend of PVDF/PVF 88.5/11.5 was higher than in the PVDF homopolymer, but it was lower than in the PVDF film with a draw ratio higher than 4. The α-crystalline phase in PVDF/PVF blends was mostly transformed into the β-crystalline phase beyond a draw ratio of 4, regardless of the draw temperature and PVF content. The α-crystalline phase of PVDF systematically transformed into the β-crystalline phase with increasing draw ratio. The crystallinity of PVDF/PVF blend films drawn at 110°C was higher than those drawn at 50°C. In the drawn blend films, characteristic IR bands of the α form were shifted to those of the β form and completely changed into those of β form at draw ratio of 4, regardless of the draw temperature and PVF content.     

用顺酐化EPDM增容的EPDM改性聚甲醛

以顺酐化三元乙丙橡胶（ＭＥＰＤＭ）为增容剂，研究了ＥＰＤＭ对聚甲醛（ＰＯＭ）的共混增韧生。结果表明，ＭＥＰＤＭ能明显改善ＰＯＭ与ＥＰＤＭ的相容性，使共混物分散相尺寸明显减少，分布更均匀，熔点和结晶度降低，缺口冲击强度提高。当ＰＯＭ／ＥＰＤＭ／ＭＥＰＤＭ（质量比）为８５／９／６时，共混物的缺口冲强度为１０．２ｋＪ／ｍ＾２。     

共混法制备酸性可染聚丙烯腈纤维

用含有碱性基团的丙烯酸氨基酯(TAM)与丙烯腈(AN)单体共聚,其共聚物与聚丙烯腈(PAN)共混,经湿法纺丝制备酸性染料可染PAN共混纤维。结果表明,AN／TAM共聚物与PAN有良好的相容性。随着TAM含量的增加,PAN共混纤维结晶度下降,力学性能下降。纤维中TAM质量分数5％较好,PAN共混纤维酸性染料上染率大于80％。     

苯乙烯和甲基丙烯酸甲酯梯度共聚物的应用

将用原子转移自由基聚合及连续补加甲基丙烯酸甲酯（MMA）的方法制备的苯乙烯（St）/MMA梯度聚合物P（Pt-t-MMA）作为增容剂应用于聚氯乙烯/苯乙烯-丁二烯-苯乙烯嵌段共聚物（PVC/SBS）和PS/PMMA聚合物合金的增容和改性。扫描电镜结果表明,P（St-t-MMA）可以改善PVC/SBS和PMMA/PS合金的相容性。PVC/SBS合金中加入少量P（St-t-MMA)后,冲击强度从6.0kJ/m^2提高到12.1kJ/m^2,加工流变性能得到了改善。SBS用量也影响PVC/SBS合金的冲击强度。     

壳聚糖/聚乙烯醇共混膜的氢键和相容性

采用溶液共混法制备了不同配比的壳聚糖/聚乙烯醇共混膜,通过变温FTIR、TG、DTA、DSC及XRD等对共混膜的结构、氢键相互作用、热行为和结晶性等进行研究。实验结果表明,共混膜中壳聚糖与聚乙烯醇间存在强烈的氢键相互作用。氢键的存在使壳聚糖的热稳定性提高,聚乙烯醇结晶性下降,促进壳聚糖与聚乙烯醇相容。当壳聚糖/聚乙烯醇共混膜的质量比分别为10/0、7/3、5/5、3/7和0/10时,共混膜的初始分解温度分别为244 ℃、257 ℃、260 ℃、262 ℃和285 ℃。聚乙烯醇熔融温度从193 ℃下降到173 ℃,玻璃化转变温度从74.2 ℃上升至80 ℃,结晶度Xc从3.57%下降到1.97%。     

PET/聚烯烃共混改性的研究进展

从聚对苯二甲酸乙二酯(PET)/聚烯烃(PO)共混物的形态结构、力学性能、结晶性能、气体渗透性能和加工流变性能、生物降解等方面详细阐述了国内外PET/PO共混改性的最新研究进展,并对PET/PO共混物的发展趋势作了简要分析.     

Preparation of POE Graft Copolymer and Its Application of Toughening Modification for PA6

A series of grafted ethylene-octene copolymers using itaconic acid (ITA) and styrene (St) as grafted monomers (POE-g-ITA, POE-g-(ITA-St)) were prepared via melt grafting technique by twin screw extrusion. The structure of grafted copolymer was characterized by FT-IR. The monomer and initiator concentration and the percent content of St in grafted monomers were also explored in the effect on the graft ratio (GR) and melt flow rate (MFR) of POE-g-ITA. The GR of POE-g-ITA reached 1.36% when when the ratio of POE:ITA:DCP is 94:6:0.36, and the GR of POE-g-(ITA-St) reached 1.44% when the ratio of POE:ITA:St:DCP = 94:3:3:0.18. The compatibilizer POE-g-ITA was introduced into PA6/POE blend by twin screw extrusion. The mechanical properties and morphological structure were investigated. The results revealed that the impact strength of the PA6/POE blend containing 5 phr of POE-g-ITA was enhanced 12.78 times compared with pure PA6. The crystallinity (X _c) of PA6 phase increased gradually when the compatibilizer POE-g-ITA was introduced into PA6/POE blends, although the melting point (T _m) of PA6 phase had no obvious change. The interface between PA6 and POE phase became indistinct and the compatibility was significantly increased.     

The reactive compatibilization effect of copolymer macroactivator for immiscible anionic polyamide 6/polystyrene blends via in situ polymerization

In this article, a novel method has been successfully developed to prepare the anionic polyamide 6/polystyrene (APA6/PS) blends. The macroactivator P(St‐co‐IEM) was synthesized by the free radical polymerization of 2‐isocyanatoethyl methacrylate and styrene (St), then the graft copolymer of PS and APA6 (PS‐g‐APA6) can be obtained by the anionic polymerization of ɛ‐caprolactam activated by the macroactivator P(St‐co‐IEM). The X‐ray diffraction analysis, differential scanning calorimetry, scanning electron microscopy analysis, contact angle measurement, water absorption measurement, molau test, thermogravimetric analysis, and mechanical properties test were performed separately to study the effects of P(St‐co‐IEM) on crystallinity, morphology, water resistance, thermal stability, and mechanical properties. The results indicate the synthesis of macroactivator can promote the formation of the γ‐phase. Moreover, it can improve the interfacial compatibility, water resistance, thermal stability, and toughness. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46302.     

Novel approach for the preparation of a compatibilized blend of nylon 11 and polypropylene with polyhydroxybutyrate: Mechanical,thermal, and barrier properties

This article comprises of the interaction in the immiscible polymer system of nylon 11 (PA 11), polypropylene (PP), and polyhydroxybutyrate (PHB). Reactive compatibilization extrusion method with maleic anhydride-grafted polypropylene (PP-g-MA) is used to achieve compatibility within the polymer. To further improve the interaction of the blend at interphase, PHB was added as a dispersive phase in a concentration varying from 10 to 40% of the total batch. Addition of PHB motives the excellent dispersion of PP chain in PA 11 and assures the compatibility between the phases of PA 11 and PP-g-MA. The entire system of tertiary and binary phases was blended in a twin-screw extruder at different composition. The macro-optimal tensile strength, Young's modulus, bending strength, and notched impact strength of PA11/PP systems were found to be superior as compared to their noncompatibilized systems. The degradation temperature of the blends of PA11/PP and PA11/PHB/PP with and without compatibilizer was evaluated by thermogravimetric analysis (TGA). It was found that the high temperature of degradation was required for compatibilized ternary blend than that of the compatibilized binary blend. The distortion temperature of the systems was studied with the help of heat deflection temperature (HDT) and found to be advanced for blend having a higher concentration of the dispersed phase. Differential scanning calorimetry (DSC) was used to determine the % crystallinity, melting, and crystallization temperature of this system. Chemical resistance and barrier properties of the different compatibilized and noncompatibilized blends were studied. PHB dispersed phase with a reactive compatibilizer cause enhancement in chemical resistance and barrier properties of the blend. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48152.     

X-Ray-Studies of crystallization in swollen polyvinyl fluoride

Polyvinyl fluoride (PVF) shows a strong crystal interference caused by the lateral distances of the chains, and is highly crystalline. Over the temperature range 0—100°C the degree of crystallinity is about 86%. Gelation of PVF in γ-butyrolactone was studied over practically the whole range of concentrations (from pure PVF to 1% solution). Gel temperatures were found practically independent of concentration (174°C). Gelation is coupled with crystallization. The swollen samples showed no differences in degree of crystallinity and quality of the crystals compared with the pure polymer at the same temperature. Therefore the degree of crystallinity of the gels is solely a function of temperature. The crosslinks of the network are formed by crystalline regions. Only the amorphous regions in the gels can take up solvent. Caused by the high crystallinity the gels have a crumb-like nature.