Preparation of Isocyanate Functionalized Ethylene Propylene Copolymer and Its Blending with Polyamide 6

本工作合成了一种含异氰酸酷功能基团的不饱和单体，（3-异氰酸酯基-4-甲基）苯氨基甲酸-2-丙烯配（TAI）。以过氧化二异丙苯（OCP）为引发剂，该单体被用于乙烯丙烯共聚物（EPM）的自由基溶液接枝官能化。纯化后的接枝产物（EPM-g-TAI）的傅立叶变换红外光谱中存在2273cm-l异氰酸酷基团（-NCO），表明异氰酸醋单体已经接枝到乙丙共聚物上。接枝率采用化学滴定和红外光谱的方法确定。与EPM相比，EPM-g-TAl的分子量分布（MMO）变窄。采用旋转流变仪测定了EPM-g-TAl的流变行为。EPM-g-TAl的表观粘度高于EPM且随接枝率的增加而增加。采用接触角测定的表面分析表明，对于给定的的极性测定液体接枝产物的接触角随接枝率的增加而增大；我们同时得到接枝产物的表面自由能（75）以及表面自由能的色散分量（γs）和表面自由能的极性分量（γsρ），这些参数随接枝率提高而增大的趋势使我们可以定量估计接枝反应对改善极性的贡献。本工作研究了（3一异氰酸酯基-4-甲基）苯氨基甲酸-2-丙烯醋（TAl）官能化乙烯丙烯共聚物（EPM-g-TAI）与尼龙6（PA6）的反应共混。傅立叶变换红外光谱表明，由于EPM-g-TAl中的异氰酸醋基（-NCO）与尼龙6中的端胺基（-NH2）之间的化学反应：EPM-g-TAI／PA6谱图中3299cm-1处的阵日伸缩振动峰变窄变高，1640cm-1处阵日变形振动峰和1547cm-1处阵日弯曲振动峰变强。同时研究了共混体系的热性能、流变性能、机械性能和形态特征。OSC结果表明，在相同的共混组成下，EPM-g-TAI／PA6共混体系中尼龙6的结晶烩（△Hc）到氏于EPM／PA6共混体系中的尼龙6，这种差别随着共混物中乙烯丙烯共聚物含量的增加而增大，说明反应共混体系中尼龙6的结晶受到一定的限制；EPM-g-TAI／PA6共混体系的复数粘度和贮能模量高于相应的EPM／PA6共混体系；与相同组成的EPM／PA6相比，EPM-g-TAI／PA6中分散相的粒子尺寸更小，粒子分布更均匀，界面粘合更强；反应共混后的机械性能如拉伸强度、杨氏模量，弯曲强度和模量、缺口及非缺口冲击强度均随着接枝率的提高而增加。Ethylene-Propylene Copolymer (EPM) was functionalized with an isocyanate-bearing unsaturated monomer, allyl (3-isocyanate-4-tolyl) carbamate (TAI), by using dicumyl peroxide (DCP) as an initiator in xylene solution. FT-IR was used to confirm the formation of EPM-g-TAI. The peak at 2273 cm-1, characteristic of-NCO groups in EPM-g-TAI, revealed an evidence of grafting occurrence. The grafting degree was determined by using both chemical titration and FT-IR. Grafting degree could be adjusted and the maximum was over 6wt% without any gelation. The molar mass distribution (MMD) of EPM-g-TAI was narrower, compared to that of EPM. Rheological behavior of both EPM-g-TAI and EPM was investigated by using a rotational rheometer. The apparent viscosity of EPM-g-TAI is higher than that of EPM and increased with increasing the grafting degree of TAI. Surface analysis by contact angle measurement showed that contact angles of EPM-g-TAI samples to a given polar liquid decrease with increasing grafting- degree of TAI. we also obtain the dispersion component of surface free energy (ysd), the polar component of surface free energy (ysp) and the total surface free energy (ys=Ysd+ysp) of the grafted EPM. These parameters increase with the enhancement of grafting degree, which gives us the quantitative estimation of the polar contribution of the grafted TAI to the total surface free energy of EPM-g-TAI. Adhesive property of EPM-g-TAI with akuninum foil was studied. The peeling strength between EPM-g-TAI plate and aluminum foil increases dramatically with enhancing grafted TAI content in EPM-g-TAI. Reactive compatibilization of ethylene-propylene copolymer functionalized with allyl (3-isocyanate-4-tolyl) carbamate (TAI) isocyanate (EPM-g-TAI) and polyamide 6 (PA6) was investigated in this paper. FTIR analysis revealed the evidence of the chemical reaction between the end groups of PA6 and EPM-g-TAI. Thermal, rheological, morphological, and mechanical properties of the resultant system were investigated. DSC analysis indicated that the crystallization of PA6 in EPM-g-TAI/PA6 blends was inhibited, due to the chemical reaction that occurs at the interface of PA6 and EPM-g-TAI. A comparison with the blends obtained from ungrafted EPM and PA6 shows that complex viscosity and storage modulus of EPM-g-TAI/PA6 were dramatically enhanced and the increase was strongly dependent upon the grafting degree of TAI. After examining the morphology of both blending systems, smaller particle size, more homogeneous distribution of "domains and improved interfacial adhesion between matrix and domains were observed in the compatibilized system. Mechanical properties such as tensile strength, Young's modulus, flexural strength and modulus, as well as notched and un-notched impact strength of EPM-g-TAI/PA6 blends were also found to improve gradually with increasing the content of grafted TAI