TY - JOUR
T1 - Synthesis and characterization of maleic anhydride grafted polypropylene with a well-defined molecular structure
AU - Zhang, Min
AU - Colby, Ralph H.
AU - Milner, Scott T.
AU - Chung, T. C.Mike
AU - Huang, Tianzi
AU - Degroot, Willem
PY - 2013/6/11
Y1 - 2013/6/11
N2 - Despite the commercial importance of maleic anhydride grafted polypropylene (PP-g-MAH), it has long been a scientific challenge to prepare this polymer with a well-controlled molecular structure. This paper discusses a new chemical route that can form PP-g-MAH with desirable MAH content, a single MAH incorporated unit, white color, high molecular weight, and narrow molecular weight and composition distributions. The chemistry involves a unique PP-co-p-BT copolymer as the "reactive intermediate" that can be effectively prepared by metallocene-mediated copolymerization of propylene and p-(3-butenyl)toluene (p-BT), with narrow molecular weight and composition distributions, high molecular weight, and a broad range of p-BT contents. The incorporated p-BT comonomer units provide the reactive sites for the subsequent free radical MAH graft reaction under a suspension condition at a low reaction temperature. The resulting PP-g-MAH polymers were carefully examined by a combination of NMR and GPC measurements, which shows almost no change in polymer molecular weight and distribution and a single MAH incorporation (no oligomerization). The incorporated MAH units increase with the increase of initiator concentration, p-BT content, and reaction time. Evidently, the combination of high reactivity of φ-CH3 moiety, a favorable mixing condition between the reactive sites and chemical reagents in the swollen amorphous phases, and low reaction temperature results in MAH grafting reaction selectively taking place at the φ-CH3 moieties without side reactions (i.e., chain degradation and MAH oligomerization). In addition, this suspension reaction process presents an economic method to prepare PP-g-MAH with high polymer content and easy product purification.
AB - Despite the commercial importance of maleic anhydride grafted polypropylene (PP-g-MAH), it has long been a scientific challenge to prepare this polymer with a well-controlled molecular structure. This paper discusses a new chemical route that can form PP-g-MAH with desirable MAH content, a single MAH incorporated unit, white color, high molecular weight, and narrow molecular weight and composition distributions. The chemistry involves a unique PP-co-p-BT copolymer as the "reactive intermediate" that can be effectively prepared by metallocene-mediated copolymerization of propylene and p-(3-butenyl)toluene (p-BT), with narrow molecular weight and composition distributions, high molecular weight, and a broad range of p-BT contents. The incorporated p-BT comonomer units provide the reactive sites for the subsequent free radical MAH graft reaction under a suspension condition at a low reaction temperature. The resulting PP-g-MAH polymers were carefully examined by a combination of NMR and GPC measurements, which shows almost no change in polymer molecular weight and distribution and a single MAH incorporation (no oligomerization). The incorporated MAH units increase with the increase of initiator concentration, p-BT content, and reaction time. Evidently, the combination of high reactivity of φ-CH3 moiety, a favorable mixing condition between the reactive sites and chemical reagents in the swollen amorphous phases, and low reaction temperature results in MAH grafting reaction selectively taking place at the φ-CH3 moieties without side reactions (i.e., chain degradation and MAH oligomerization). In addition, this suspension reaction process presents an economic method to prepare PP-g-MAH with high polymer content and easy product purification.
UR - http://www.scopus.com/inward/record.url?scp=84878993117&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84878993117&partnerID=8YFLogxK
U2 - 10.1021/ma4006632
DO - 10.1021/ma4006632
M3 - Article
AN - SCOPUS:84878993117
SN - 0024-9297
VL - 46
SP - 4313
EP - 4323
JO - Macromolecules
JF - Macromolecules
IS - 11
ER -