Melting crystallization behavior of nylon 66

Analysis of isothermal and nonisothermal crystallization kinetics of nylon 66 was carried out using differential scanning calorimetry (DSC). The commonly used Avrami equation and that modified by Jeziorny were used, respectively, to fit the primary stage of isothermal and nonisothermal crystallizations of nylon 66. In the isothermal crystallization process, mechanisms of spherulitic nucleation and growth were discussed. The lateral and folding surface free energies determined from the Lauritzen-Hoffman treatment are sigma = 9.77 erg/cm(2) and sigma (e) = 155.48 erg/cm(2), respectively; and the work of chain folding is q = 33.14 kJ/mol. The nonisothermal crystallization kinetics of nylon 66 was analyzed by using the Mo method combined with the Avrami and Ozawa equations. The average Avrami exponent (n) over bar was determined to be 3.45. The activation energies (DeltaE) were determined to be -485.45 kJ/mol and -331.27 kJ/mol, respectively, for the isothermal and nonisothermal crystallization processes by the Arrhenius and the Kissinger methods.

Crystal transitions of Nylon 11 under drawing and annealing

The crystal transitions of Nylon 11 annealed and drawn at different temperatures (T-d) with different drawing ratios (n) were investigated by wide-angle X-ray diffraction (WAXD). The alpha -form of Nylon Il could be transformed from the delta'-form by annealing at high temperature, The results showed that the crystal transitions of Nylon 11 strongly depended on the thermal history and the conditions of drawing. The delta'-form Nylon Il could he gradually transformed into the alpha -form when it was drawn at high temperature and the alpha -form was only partly transformed into the delta'-form when it was drawn at low temperature. This should be due to the effect of the competition between thermal inducement and drawing inducement. The thermal inducement was favorable to producing the alpha -form, while the drawing inducement was favorable to producing the delta'-form. (C) 2001 Elsevier Science Ltd. All rights reserved.

Lamellar single crystals of nylon-10,10 crown from a dimethylformamide solution

A new solvent, dimethylformamide (DMF), and the traditional solvent, 1,4-butanediol, were used to prepare single crystals of nylon-10,10 from a dilute solution. The lamellae grown from DMF inhabited a more perfect structure and regular shape than those crystals crystallized from traditional solvents such as 1,4-butanediol and glycerin. These thin and perfect lamellar crystals demonstrated patterns of variation in spacing different from those of melt-crystallized spherulites on heating. Specifically, the two main spacings slightly separated rather than continuously approaching each other when the temperature was greater than 180 degreesC. This is a novel phenomenon observed in nylons. Nevertheless, the usual pattern of change in spacing was observed during the cooling process. These lamellar crystals showed more compact spacing of the (002) and (010/100) planes than spherulites at room temperature. (C) 2001 John Wiley & Sons, Inc.

Morphology and structure of micro-fibrillar crystal of nylon 10 10

The nanoscale and microscale fibrillar crystals of nylon 10 10 were obtained by atomizing the very dilute formic acid solution. The length-diameter ratio of these fibrillar crystals increases as the concentration of the atomizing solution increases. Electron diffraction (ED) analysis showed that the hydrogen-bonded sheet in these solution-grown fibrillar crystals was imperfect and had a lower order. Both electron diffraction and characteristic morphology show that melt-crystallized fibrillar crystals always possess perfect packing order and stable structure. A rather perfect ED pattern of the triclinic form of nylon 10 10 along the [001] zone was obtained by tilting the specimen 41 degrees along the elongated direction of the crystal. Fibrillar crystals from bulk have a great tendency to aggregate with parallel packing to form crystal clusters, which look like shish kebabs in morphology. Spherulite is observed occasionally in the domains with very rich sample. (C) 2001 Elsevier Science Ltd. All rights reserved.

拉伸条件对尼龙1010拉伸强度的影响

研究了拉伸温度 T与拉伸速率 v对尼龙 10 10拉伸性能的影响。结果表明 ,随 T升高 ,弹性极限强度 σa、表观杨氏弹性模量 Ea、屈服强度 σy 和应变硬化强度 σt均降低 ;弹性极限伸长 εa 在约 5 0℃时有一极大值 ;当 T≥ 5 0℃时屈服应变 εy 与 T无关 ,而 T=18℃时的 εy低很多。随拉伸速率 v的加快 ,T=18℃、=5 0 mm/ min时 Ea 有一极大值 ;σa、εa、σy、σt和 T≥ 5 0℃后的 Ea 均基本不受 v的影响。

拉伸取向尼龙1010样品的抗张回复

研究了拉伸取向尼龙 10 10的抗张回复现象 .残存应变ε′表征了由链滑移而产生的永久形变 ,回复应变(ε -ε′)表征了键角变化和链段取向产生的形变 .当拉伸温度T=18℃

Blends of polyamide 1010 with ungrafted and maleic anhydride grafted high impact polystyrene

The crystallization, dynamic mechanical properties, tensile properties and morphology features of polyamidel 1010(PA1010) blends with the high impact polystyrere (HIPS) and maleic anhydride (MA) grafted HIPS(HIPS-g-MA) were examined at a wide composition range. By comparison the PA1010/HIPS-g-MA and PA1010/HIPS binary blends, it was found that the size of the domains of HIPS-g-MA was much smaller than that of HIPS at the same compositions. It was found that the mechanical properties of PA1010/HIPS-g-MA blends were obviously higher than those of PA1010/HIPS blends. When the content of PA1010 is more than 50wt% in the blends, the crystallization temperatures, T-cs, of PA1010 increase with increasing the content of HIPS-g-MA. On the other hand, when the content of PA1010 in the blends is less than 35wt% the fraction crystallization is observed. The same result is not obtained for the blends of PA1010/HIPS. These behaviors could be attributed to the chemical interactions between the two components and good dispersion in PA1010/HIPS-g-MA blends.

Influence of interface on radiation effects of crystalline polymer - radiation effects on polyamide-1010 containing BMI

Aimed at saving the radiation dose required to crosslinking the polyamid-1010, BMI/PA1010 systems containing different amounts of difunctional crosslinking agent N,N'-bis-maleimide-4,4'-biphenyl methane (BMI) were prepared and the structure changes at the crystallographic and supermolecular levels before and after irradiation were studied by using WAXD, SAXS, and DSC techniques. It was found that by incorporation of BMI the microcrystal size L-100 is lowered due to the formation of hydrogen bond between the carbonyl oxygen of BMI and the amide hydrogen of PA1010 in the hydrogen bonded plane, and the overall crystallinity W-c is also decreased. The presence of BMI causes the crystal lamella thickness d(c) to decrease and greatly thickens the transition zone d(tr) between the crystalline and amorphous regions. As for the irradiated specimen, the maximum increments in the L-100 and W-c against dose curves decrease with BMI content, and the interception point D-i, at which the L-100 and W-c curves intercept their respective horizontal line of L-100/L-100(0) and W-c/W-c(0)=1, shift to lower dose with an increase in BMI concentration. In addition. the mechanism of the radiation chemical reactions in the three different phases under the action of BMI are discussed with special focus on the interface region. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.

Studies on the interfacial adhesion between functionalized polypropylene and polyamide 1010

The interface behavior of polyamide 1010 (PA1010) and polypropylene (PP) was studied. In order to improve their interfacial adhesion, functional PP was prepared by means of grafting glycidyl methacrylate (GMA) on PP main chains and used instead of plain PP. Several technological characterizations were performed here on their interfaces. ESCA was used to confirm that some kind of reaction occurred between end groups of PA1010 and epoxy species of PP-g-GMA. The peel test was adopted to measure interfacial adhesion. It was found that the fracture energy of interfaces between PA1010 and PP-g-GMA was dramatically increased with the content of GMA. Their interfaces were observed as being blurred by using SEM and TEM and a crack that could be seen in the case of the interfaces of the PA1010 and the plain PP disappeared.

Preparation of the HIPS/MA graft copolymer and its compatibilization in HIPS/PA1010 blends

The graft copolymer of high-impact polystyrene (HIPS) grafted with maleic anhydride (MA) (HIPS-g-MA) was prepared with melt mixing in the presence of a free-radical initiator. The grafting reaction was confirmed by infrared analyses, and the amount of MA grafted on HIPS was evaluated by a titration method. 1-5% of MA can be grafted on HIPS. HIPS-g-MA is miscible with HIPS. Its anhydride group can react with polyamide 1010 (PA1010) during melt mixing of the two components. The compatibility of HIPS-g-MA. in the HIPS/PA1010 blends was evident. Evidence of reactions in the blends was confirmed in the morphology and mechanical behavior of the blends. A significant reduction in domain size was observed because of the compatibilization of HIPS-g-MA in the blends of HIPS and PA1010. The tensile mechanical properties of the prepared blends were investigated, and the fracture surfaces of the blends were examined by means of the scanning electron microscope. The improved adhesion in a 15% HIPS/75% PA1010 blend with 10% HIPS-g-MA copolymer was detected. The morphology of fibrillar ligaments formed by PA1010 connecting HIPS particles was observed. (C) 1999 John Wiley & Sons, Inc.

尼龙1010分别与未接枝和接枝马来酸酐的高抗冲聚苯乙烯的共混体系研究

研究了尼龙1010(PA1010)与高抗冲聚苯乙烯(HIPS)及马来酸酐官能化的HIPS(HIPS-g-MA)间的相互作用，利用DSC,DMA,SEM及拉伸测试等方法研究了不同组成比的共混物PA1010/HIPS与PA1010/HIPS-g-MA的结晶、玻璃化转变、形态及力学性能．结果表明HIPS与PA1010虽然结构相差甚远，但两者之间仍存在着一定的相互作用；而HIPS-s-MA可使PA1010的低温熔融峰变小，当HIPS-g-MA的含量≤50%时，随着其含量的增加，共混物中PA1010的结晶温度升高；当含量＞50%时，PA1010发生分级结晶行为，其结晶温度由原来的178℃降至83℃，同时HIPS-g-MA与PA1010间的相互作用变大，DMA谱上有明显的新的松驰峰．PA1010/HIPS-g-MA共混体系的拉伸性能要优于相同组成的PA1010/HIPS体系．以上现象主要是...

尼龙1010/6及尼龙1010/66基本物理性能与组成的关系

尼龙1010/6 和尼龙1010/66 的基本物理性能随着组成的改变而改变,尼龙1010 含量高时,共聚物密度大于计算值;含量低时,共聚物密度小于计算值.尼龙1010 含量20%左右时,共聚物具有较大吸水率

The characterization of the interfacial reaction in polyamide 1010 poly(propylene)-graft-(glycidylmethacrylate) blends

Binary blends of polyamide 1010/poly(propylene) and polyamide 1010 (PA1010)/poly(propylene)-graft-(glycidyl methacrylate) (PP-g-GMA) were prepared. The epoxy groups in PP-g-GMA react with the amino end-groups in PA1010, thus a PA1010-graft-PP copolymer is formed and acts as a compatibilizer between PA1010 and PP-g-GMA. The reaction was confirmed by electron spectroscopy for chemical analysis (ESCA) and attenuated total reflection (ATR)-FTIR spectroscopic analysis, and also evaluated by the stability of the suspension obtained by dissolving the blends in formic acid and by the morphologies of the blends.

Isothermal and nonisothermal crystallization kinetics of nylon-11

Analysis of the isothermal, and nonisothermal crystallization kinetics of Nylon-11 is carried out using differential scanning calorimetry. The Avrami equation and that modified by Jeziorny can describe the primary stage of isothermal and nonisothermal crystallization of Nylon-11. In the isothermal crystallization process, the mechanism of spherulitic nucleation and growth are discussed; the lateral and folding surface free energies determined from the Lauritzen-Hoffman equation are sigma = 10.68 erg/cm(2) and sigma(e) = 110.62 erg/cm(2); and the work of chain folding q = 7.61 Kcal/mol. In the nonisothermal crystallization process, Ozawa analysis failed to describe the crystallization behavior of Nylon-ii. Combining the Avrami and Ozawa equations, we obtain a new and convenient method to analyze the nonisothermal crystallization kinetics of Nylon-11; in the meantime, the activation energies are determined to be -394.56 and 328.37 KJ/mol in isothermal and nonisothermal crystallization process from the Arrhonius form and the Kissinger method. (C) 1998 John Wiley & Sons, Inc.

Crystallization and melting behavior of nylon 66 poly(ether imide) blends

Isothermal crystallization and melting behavior of nylon 66 and its blends with poly(ether imide) (PEI) were investigated by differential scanning calorimetry. Crystallization kinetics such as overall rate constant Z and index n were calculated according to Avrami approach. Crystallization in the blend was retarded with respect to that of pure nylon 66 by incorporation of PEI with high glass transition temperature (T-g). The lowest growth rate of the spherulites was observed in the blends containing 10 and 15 wt% fraction of PEI. A transition temperature where positively birefringent spherulites disappear and negative birefringent spherulites develop was measured by thermal analysis. The transition temperature increased with content of PEI in the blends. A suitable range of isothermally crystallization temperatures, 238.5-246 degrees C, is suggested For determining the equilibrium melting points by means of Hoffman-Weeks approach.