Bulk functionalization of ethylene–propylene copolymers. III. Structural and superreticular order investigations
Bulk functionalization of ethylene–propylene copolymers. III. Structural and superreticular order investigations
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DOI：
10.1002/app.1989.070370315
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发表时间：
1989-01
影响因子：
3
通讯作者：
R. Greco;P. Musto;F. Riva;G. Maglio
中科院分区：
文献类型：
--
作者：
R. Greco;P. Musto;F. Riva;G. Maglio
采用自由基引发的本体法，用马来酸二甲酯（DBM）对乙丙共聚物（EPR）进行官能化。通过改变反应混合物的总体组成以及加工程序，已经获得了不同程度的接枝。通过差示扫描量热法（DSC）、傅里叶变换红外分析（FTIR）、广角X射线散射（WAXS）和小角X射线散射（SAXS）技术研究了接枝度对结构和超网状（或“长程”）有序度的影响。官能化导致母体共聚物中存在的“残余结晶度”降低。用DSC和WAXS测定了接枝率与结晶度X_c之间的线性关系。的结构调查的结果，在协议与以前报道的，表明接枝优先发生在更长或更完美的亚甲基序列。SAXS研究表明，结构化的显着程度，即，存在于母体弹性体中的结晶和次结晶顺序通过增加接枝度而逐渐消失。
An ethylene-propylene copolymer (EPR) has been functionalized with dibutyl maleate (DBM) by means of a radical-initiated bulk process. Different degrees of grafting have been obtained by varying the overall composition of the reaction mixture as well as the processing procedures. The influence of the grafting degree on the structural and superreticular (or “long range”) order has been investigated by differential scanning calorimetry (DSC), Fourier transform infrared analysis (FTIR), and wide (WAXS) and small angle X-ray scattering (SAXS) techniques. The functionalization leads to a decrease of the “residual crystallinity” present in the parent copolymer. Linear relationships between the grafting degree and the crystallinity degree Xc evaluated by both DSC and WAXS have been obtained. The results of the structural investigations, in agreement with previously reported ones, suggest that the grafting preferentially occurs onto the longer or more perfect methylene sequences. SAXS investigations showed that the significant degree of structuration, i.e., crystalline and paracrystalline order, present in the parent elastomer, gradually disappears by increasing the degree of grafting.